Seriously.... thank you for all of your videos.. I’ve watched a fair amount of your posts but never commented, but dammit it’s time.. The range of subjects and processes that you tackle are a GOLDMINE to makers, breakers, thinkers, and tinkerers, and you should know that your time and effort is most definitely appreciated. You explain each process in such a way that it almost seems like you know what I’m going to ask before I do. All in all, every one of your videos have taught me something invaluable or made me think about a process/project in a new way. To be completely honest, half of the time I end up at one of your videos by accident through auto play or the random suggested video scroll panel; now being a perfect example. I started out researching piezoelectric synthetics and their frequencies aaaaand now I’m here lol.. That being said, Im pretty happy that I landed on this particular video though, as Ive been thinking hard about a homemade boat project and had all but written off the idea of using wood (of any type) for the the frame/stringers. After seeing this video though, balsa frames aren’t looking too shabby (when compared to the cost/weight of composite paneling)... Thank you very much for walking through materials comparison and epoxy/filler process! Anyway, sorry for the novel.. I just wanted to thank you for taking the time to make these videos and (more importantly) for going into such fine detail and explaining the science, nuances, and reasoning behind each project. It is very much appreciated. Best, Thomas
Thanks, that's very kind and it's reassuring to hear that after spending a considerable amount of time on these projects. Oh, we're currently building a hydrofoil catamaran.
so.......I've found some cool channels over the years. & this is one of the coolest. Perhaps google upgraded its recommendation algorithms or I just got lucky. It was a great find though. Interesting & useful yet somewhat diverse content. I already got more stuff than I have time to watch, which is why I hardly ever need to seek out new channels. & damn this dude is smart. & man do I wish I could afford all that nifty apparatus myself. I Need a neighbor like this.....I'm considering relocation lol.
this is the best channel since I found AvE many years ago. and thanks to this excellent video I have a newly found love and appreciation for Balsa wood! thank you!
Give a man sealed balsa wood and he’ll make a composite core structure for a day. Teach a man how to seal balsa wood and he’ll make composite core structures for a lifetime.
Absolutely love your work. I am employed as a machinist/technician at Carleton University, Canada's premier university for mechanical engineering. I am involved in a large variety of projects from aerospace, mechatronics to biomed and beyond. It just never stops and that's great!! :). Your lab is fantastic...cozy and very cottage like. Seems like a good place to sleep. Ha Ha! I am eager to watch ALL of your stuff and to see future vids as well. I agree with some of the other comments regarding the music. Just doesn't fit the mood. Wishing you the best. With respect. Ian
This is so cool. Why have I never seen this channel before? Great work guys and I love seeing the material experimentation for all of these projects. It's awesome that you guys do solid research for your projects rather than just throwing a bunch of stuff together hoping that it works out. Keep up the great videos!
Great video and explanation of how (sandwich) fillers work, and tradeoffs. Love the info on balsa. I have not used it yet, but this video has convinced me to get some to experiment with. I am working on a project which will require every lightweight construction technique I can come up with.
Thanks for putting this info up. Happy to have come across your video. I have been debating core materials for the last 6 months to use on a fire wall repair on my Lotus Europa. I had looked into Coosa board and Nida Core manufactured materials, but after your demonstration of the properties of end grain balsa I think I have a winner. I also appreciate the extra info on proper preparation with coating epoxy/micro balloons on the core to promote adhesion and reduce wicking.
Great way to avoid the balsa from sucking up a bunch of epoxy with the micro spheres. I assumed you were going to use a higher viscosity epoxy that didn't wick, but this is a far better solution. Really interesting channel, I just discovered it today and am looking forward to going through your videos.
I usually just use one resin, a very low viscosity infusion resin, and no additives. To avoid excessive wicking I just brush on a Layer, wait until its geltime is reached and proceed. With extremely spongy and sucky materials I do it twice if needed. Tested it and in many cases it's lighter and stronger as well compared to other solutions, the bonding is way better. Test pieces didn't delaminate/buckle or whatever, like they did with about any other method, the core material simply ripped apart. And not just end grain Balsa, even with Baltic Birch, Acorn etc., Airex or XPS - the poor folks Airex - of course just crumbles no matter which way. I believe it makes the core material an integral part of the composite structure, with a wet-in-wet layup on top of a "wood epoxy composite" instead of incorporating a failure point on purpose, and with the gradually decreasing epoxy content in the wood it seems to have an excellent load distribution. It's rather hard to get the process perfectly repeatable though, a spray gun and metered amounts would be the least I guess. But as amateur or for one offs - who cares? Try it! It's simple and you don't need any unnecessary additives.
You have a incredible ability to teach with efficiency in doing so that astounds me,I genuinely hope you make good from doing these videos cause you deserve every bit
Every single time that I see one of your videos, I know I'll learn something new, and every single time I am amazed at how much information and details about a very specific subject you can deliver! Simply amazing Thanks
Fantastic videos. Please consider sharing your material sources. I think you could do well with affiliate sales from your website; cross listed and/or indexed by technology, videos and kits. Sourcing is half the battle for breaking into new technologies. Great shop/studio!
Gosh! I've recently watched some of your more recent videos about resins, but only just realised the breadth of your expertise across a range of technologies. This is all as impressive as it is meticulously explained.
Very cool, worked the aerospace industry for 30 years and seeing balsa core brings back memories, I also play with pulsejets so I’m looking forward to seeing the ideas for making yours more efficient. I’m burning 500cc/min to produce 12-18 lbs of trust. I’m high for the amount of thrust but don’t burn valves at any rate.
Thank you for the work you do on these videos. They have inspired my to research areas of science I wouldn't have otherwise. UA-camrs like you reinvigorate my passion for science.
You are my science guru. It seems as though every project I stumble into, you tie in as source material in some form or another. Thank you, and please, keep it up!
Thank you for the inspiration once again for self study into material sciences. Your videos are spot on, and you are a phenomenal teacher, not to mention i appreciate you trying to be precise with terminology. That really helps my searches.
I really appreciate the effort and care that you put into your videos. In this specific video, the background audio is really diverting my attention though. It made me stressed and unfocused. You have made some great improvements in the video production of your more recent videos. Very glad to see these changes. :) On the subject of how you explain and go about practical projects, I'm very impressed. Way to go! Excited for all upcoming content. Thank you!
Thank you so much for this video. I've been looking for something that will provide a core for S2 fiberglass for building battery boxes for electric sprint karting that are both light and very strong (especially impact) while also resisting heat. I had looked at a lot of foams and hexagon materials that are as you say, very pricey or not that rigid. This seems like the best of both worlds.
Very good video and I have subscribed. Epoxy resin to hardener ratios are commonly specified by volume. Using a scale is more accurate (especially with smaller batches), less wasteful and less messy. Some epoxy manufactures give alternate ratios by weight, others don't but you can calculate it if you can get the densities from the product data sheets. For the products I use 2:1 by volume translates to 100:46 by weight, and 3:1 volume is 100:32 by weight.
It's good to see you making a video in my field of work, I would tend towards using a vacuum to pre impregnate the core when using epoxy, especially for balsa wood its ability to wick is astounding or even using a thickened isothalic resin which gives less working time but uses less material.
Hi and Thank you ! Super interesting. Like taking physics and chemistry which teachers always wanted to flunk me in though I liked them so much ! Yayyyyyy UA-cam and Tech Ingredients !!!!!!!!
I really wish there wasn't music throughout the video. your more recent videos are so much better. I am very thankful for your channel. Please keep making videos.
I clicked on this video and seen that it had a thumbs down and I never did such a thing,maybe a glitch? I wonder..I changed it to a thumbs up cause all your videos deserves a thumbs up for sure
Thanks for checking! Like other channels we have also had viewers complain that they were involuntarily unsubscribed. UA-cam has been redirecting viewers away from original content creators and toward corporate sites beginning around 2016. As you say, this may be just a glitch...
I realize this is an old video and you'll not read this but I must say that your explanation of the forces at the beginning was excellent. You said the top is under tension and bottom under compression, which is how the limbs of bows work. This year marks my 42nd archery season and I collect bows. It is interesting how different cultures solve these parameters.
The very successful WW2 fighter bomber, the Mosquito, used a lot of balsa in its construction. Very good material, probably under rated in todays high tech world. Excellent video; I learnt a lot.
One of the most educational channels on YT. Priceless for the time spent. I wonder if instead of filling the balsa with "nothing" (the micro spheres and the additional epoxy ) one would not get the same result by placing the mixed epoxy on the carbon fiber and laying flat the balsa on top letting them cure this way and then repeating the process for the other side. Some epoxy might capillary creep into balsa upwards but I doubt it to be too much. Just a thought... Anyway, I have learned a lot from you, so... thank you and keep up the fun education for the rest of us.
@@TechIngredients Thank you! Another afterthought I had (after initial posting) was to lightly sandblast (or sandpaper) the carbon fiber creating some retention (wetting) A lot of fun anyway, thanks again.
Great video. Love all your great videos. Hopefully if possible please do video on FLASH GRAPHENE or something similar. I am planning to build the required capacitor bank on the lines of Rice University experiment.
Len d I don’t think this is cross-grain balsa. That sounds like plywood. This is end-grain balsa. It is put together in small squares where the glued edges are the long grain, not the end grain. I think the manufacturers of sheets of end-grain balsa do this because one of the drawback is to this material is if the costing fails, in an underwater setting like the hull of a boat, or even on the deck, the balsa will wick water and saturate very quickly, and it rots very quickly. Making the sheet from small squares reduces how far and how quickly the water will migrate.
@@oddjobbobb The reason for using end grain balsa was explained early in the video with the bunch of straws, it has higher strength against bending when laminated.
Again a great video. I had no problems with the background music, but reading other comments, I think you could set the music volume to be slightly above "barely hearable". My main motivation for this comment, though, is that I think one could be a little more 'lazy' and give the carbon fiber sheet a coat of epoxy, then wait until it started hardening but still "tacky", then add the Balsa; I believe the epoxy would not get too deeply into the Balsa then. I also thought about the foam... popsicle+foam+popsicle+foam+popsicle ... this would only give you stiffness in one direction, though - however if you have no Balsa but a lot of foam and thin strips of wood, it could be an alternative to get lightweight stiffness. One could also use a bunch of thin strips to make a "torsion-box". -Or if you have a bunch of corrugated cardboard (it can be acquired as "paper-ish" rolls), you could make sheets / rolls and slice them into boards using a cheap (large) handsaw - thinned PVA glue is usually fine for gluing cardboard sheets (eg. from box sides).
I feel like this would be a very good application of stabilizing resin, apply it to balsa prior to carbon fiber application. Downsize is the cost and added weight, but you may see some significant increases in rigidity and hardness.
Absolutely fantastic content! Also watched the 'Easy Tricks Using Fiberglass Strengthening!' and I could't stop. So much knowledge, thank you for sharing it! I came across your channel looking for a solution. I'm building a sit/stand desk with quite a bit of weight of equipment attached to it. I decided to reinforce it with two steel plates where I would place two heavy-duty monitor arms. The problem is that the plates added quite a bit of weight, so much so that there is much more stress on the rear legs than the front ones (it's a 4-legged frame, with 4 separate motors). This contributes to a significant wobble at the start and finish of the motors' operation. Would you be able to recommend some kind of material I could use instead of the steel plates? It doesn't have to be the lightest possible (like balsa wood) but the steel in an overkill in this case.
This is the best channel ever! A lot of these topics are things i'm quite familiar with so I always start watching this thinking i won't new anything new in terms of science but i might get inspired to try some new technique or whatever.. So far, i've never been right about the science part lol. The diversity of in-depth information keeps surprising me every time and its so impressive that your knowledge stretches out over such a wide range of expertise. Thanks again teach! keep em coming! PS. Could you tell me if the tubular orientation in your piece of balsa wood is manufactured like that specifically for use as a hybrid composite core, or is it a typical characteristic of sheets of balsa in general (im referring to the panels i can buy at my local hobby shop, would they most likey be suitable for this application?) cheers
Thanks for your kind words! Regarding the balsa, typical hobby balsa will not work. The tubular orientation is parallel to the surface in these boards. End grain balsa is specifically fabricated as a core material with its vertical grain orientation. It also makes for nice speaker panels if you have any left after your project.
In aircraft a similar product is GLARE glass laminate aluminium reinforced extrusion. Strong as and light as. Another one is a hexagonal aluminium sheet that’s about 10mm thick the hexagons are on the vertical axis and the aluminium is goddessly thin as in thin enough to easily slice your finger. And that honeycomb sheet has a GLARE top bottom and sides and is rigid in all dimensions with fantastic sheer strength. The GLARE outer layer is only about 1.2mm thick and has 2 aluminium layers between 3 glass layers. I’m sure there are more sizes but this is the one used at my work to make chart tables in the rear of our surveillance aircraft. They weigh less than the scales that measure them and can be stood on by an adult male. Well by you but not the average USA male these days. The sheet structure comes in very large panels and you cut it to shape and add the edging. I haven’t done it myself but I have seen a damaged table top that had a corner gouged out be repaired and the engineer said that once the crushed edge was removed that you just re edge it like it was originally and it just as strong as before. And I watched him do that. I’m the captain so I’m responsible and it was interesting as all get out. And yes I bled all over the floor and my flight suit playing with the cutoff. The air gap between the layers is sound muffling and the laminated faces reduce sharp sounds.
I've done this with boat repair. Used fiberglass rather than carbon fiber. West System sells the epoxy and a wide variety of fillers with various properties. If you look up boat repair you can get many good tips (and some bad ones).
My problem with balsa as a composite filler is largely the same as my problem with most composite filler: water intrusion. After some number of years, some point on a boat hull is going to develop a hole the size of a pin that allows water to contact the filler material. Thermal expansion/contraction will force water in. Most composite filler materials quickly start turning into structurally useless mush. And the mush spreads. Below the waterline there's no composite filler that really lasts. If you want a boat to last more than a few seasons you have to get an old boat from when nobody even tried to do fancy layered composites and they were made in solid (and yes, heavy) fiberglass all the way through.
A poor layup leaves behind microscopy air bubbles! Usually from working the fiberglass to fast. Yes, it can take on water over time and can cause severe damage!
I agree but I also find the content entertaining , I will say trying to imagine technical content with music going for me is tough but I have a coworker that is the total opposite..
I read down quite a ways looking to see if my question was already asked, but I didn’t see it. I am curious why you don’t immediately lay at least a lightweight piece of glass in the thickened resin a soon as you have the balsa coated. I NEVER fail to learn from your videos.
Pallets for military and commercial aircraft utilize two inch cross grain balsa and .040" aluminum. These are 8x8 foot pieces. Very little bending and very light. Only downside is corrosion. I'm thinking you built a composite aircraft (VariEze) or some other Rutan design. Nice work.
Thanks for the nice video's! I watched a lot of them the last 2 days and learned a lot, I'm happy to have added you to my subscriptions list :) A question about these core constructions, did you consider a 3D printed core? I am working on an RC paramotor at the moment and am using a composite core construction but in this case the core is made of printed plastic. The thing I like about it is that you are free to make more complex shapes and the shapes get replicated accurately. The internal construction of the printed parts can easily be configured to be optimized for the load you expect to put on it.
Welcome and thanks. We have considered 3D cores. The engineered strength and dimensional freedom are attractive. The relatively slow printing speeds, so far, are not. Nevertheless, it's only a matter of time before the 3D systems become fast enough and the material prices drop from proprietary to commodity.
Thanks for the answer! I understand that it is not even close to beeing an alternative in a production sense. I was mainly/only thinking about one-off jobs or small hobby runs as you are doing with these propeller blades. There are quite quick alternatives for FDM printers though, with large diameter nozzles and double heater elements that can make large shapes reasonably quick. it does require more sanding though to get the surface flat.
I recently discovered your channel and it's fantastic. You are very good at delivering technical information in a very accessible way. With this composite video, it didn't address an issue that came up after I watched the video noted below. I'm trying to understand the interplay of differing materials used in composites used in surfskis The typical configuration is some combination of Kevlar, carbon fiber and nomex honeycomb. The properties of those materials seem to be at odds with each other. They also don't seem to address the common failure point just fore and aft of the cockpit when the surfski breaks through a wave and crashes down on the other side. There is a strong compression on the top and a strong tension force on the bottom. This would presumably cause Kevlar to fail at the compression side. Choosing a single material that is better at handling all forces compared to the darlings of Kevlar and Carbon would seem appropriate. That being S-glass. Can you point me to any sources I can investigate to get clarification? Thank you.
S glass is actually stronger than carbon and tougher than Kevlar. The downside is that it's significantly heavier. It works well in both compression and tension.
@@TechIngredients so do you prefer a single fabric on the outside layers or is a combination of materials, at locations specific to their stresses with other beneficial properties like being lighter
This topic was well presented. May I ask a few questions. NOTE, I ask these questions because I have not yet found any other site that discusses the weight (or specific density) of the end grain balsa that is sealed with any material and also provides the weight of the reference balsa that is unsealed. ~~ Have you or anyone developed an optimized sealer for balsa where the control (reduction) of weight is the primary objective? ~~ Can the phenolic spheres be measured by volume in order to simplify the formulation? ~~ When purchasing the end grain balsa, what density did you purchase and did you weight the balsa prior to your demonstration? ~~ What was the weight of the resin/phenolic mixture that you prepared and what was the remaining weight after you applied it to your sample? ~~ With a scale that can weigh materials to 0.01 grams, could the formulations be developed based on weight? ~~ How much weight of epoxy in the carbon fiber sandwich would be saved by sealing the end grain balsa? ~~ Are there any published sources for this information related material weight?
Those are a fair number of questions. We used the most common balsa density of 6.5 lb/cubic foot. The phenolic microspheres are the lightest available filler for thickening the epoxy. The approximate density of the thickened epoxy is 70% of the pure epoxy. The quantity used is variable and depends significantly on your application technique. Do not attempt to apply the cloth whether carbon or glass to unsealed balsa because the balsa will wick away the epoxy from the interface and prevent a good bond.
Thanks for the videos, I love seeing some productive content rather than recycled rubish! I am curious though, do you feel this would seal the balsa enough to prevent rot long term? I would be worried about any penetration (e.g. screwing something into a panel) that might cause rot later.
It works pretty well, but it still is a cellulose based material. Regarding fasteners, bore a hole much larger than the screw all the way through the first skin and the core, but not through the second skin. Fill the hole with thickened epoxy and once curred, screw into this.
I love this channel! I keep ending back here for great DIY projects. I am watching this video as part of my quest to finding the best material for the DML loudspeaker you've also covered - have you considered testing the audio exciters on a panel of the balsa sandwich material? Or foam core carbon fiber panel?
Yes. The increased stiffness produced by the outer layer of cloth significantly reduces the sound output of the panels especially at the lower frequencies.
Great channel ! Super content. I was wondering what needs to be done to ensure the filled epoxy layer on the balsa adheres well to the carbon fiber layer? Sandpaper? flame ? plasma? THX.
Just revisiting this video after rewatching the "Super Strong Epoxy with Diamonds and More!" video from 2020. Out of those materials presented, would you stick with the phenolic microspheres for this application? The thought is to build a lightweight plane wing so with the UV exposure, maybe one of the powders from that video (graphite, aluminum, dendridic copper) would also be a good additive. In this instance, it would of course only make sense using balsa wood vs a foam core since the foam can be used with plain epoxy.
Interesting. I wonder if this could be used to skin/wrap (for structural purposes) somewhat porous wooden guitar neck, leave it to dry until it's tacky and then apply different carbon fiber layers with additional normal resin? The idea would be to grain fill porous wood, so it's not to shallow and not too deep into the wood, and at the same time (without sanding stages in between) form better bond between wood, filler, carbon fiber and resin.
Balsa is not cheaper than foam in the northeast US. For example, 1" 4x8 XPS is about $20. By comparison, the same square footage of balsa 3/8" thick is about $120, and you probably have to pay shipping as well since it is not usually available locally.
Great video. Could you add reference as to where to get the materials including carbon fiber? This could help in getting support for these video from suppliers.
I've found that when mixing epoxy if I mix it until well mixed, then put the contents into a new clean container and mix it some more I get a MUCH more consistent mixture.
Seriously.... thank you for all of your videos.. I’ve watched a fair amount of your posts but never commented, but dammit it’s time..
The range of subjects and processes that you tackle are a GOLDMINE to makers, breakers, thinkers, and tinkerers, and you should know that your time and effort is most definitely appreciated.
You explain each process in such a way that it almost seems like you know what I’m going to ask before I do. All in all, every one of your videos have taught me something invaluable or made me think about a process/project in a new way. To be completely honest, half of the time I end up at one of your videos by accident through auto play or the random suggested video scroll panel; now being a perfect example. I started out researching piezoelectric synthetics and their frequencies aaaaand now I’m here lol..
That being said, Im pretty happy that I landed on this particular video though, as Ive been thinking hard about a homemade boat project and had all but written off the idea of using wood (of any type) for the the frame/stringers. After seeing this video though, balsa frames aren’t looking too shabby (when compared to the cost/weight of composite paneling)... Thank you very much for walking through materials comparison and epoxy/filler process!
Anyway, sorry for the novel.. I just wanted to thank you for taking the time to make these videos and (more importantly) for going into such fine detail and explaining the science, nuances, and reasoning behind each project.
It is very much appreciated.
Best,
Thomas
Thanks, that's very kind and it's reassuring to hear that after spending a considerable amount of time on these projects.
Oh, we're currently building a hydrofoil catamaran.
so.......I've found some cool channels over the years. & this is one of the coolest. Perhaps google upgraded its recommendation algorithms or I just got lucky. It was a great find though. Interesting & useful yet somewhat diverse content. I already got more stuff than I have time to watch, which is why I hardly ever need to seek out new channels. & damn this dude is smart. & man do I wish I could afford all that nifty apparatus myself. I Need a neighbor like this.....I'm considering relocation lol.
I just had the same experience :)
Agreed. I'm really impressed at his knowledge base.
Let's all be his neighbor. We'll start a cult of engineers and end up migrating to Mars in 20 years.
what are your other favorites?
Same homie. I’d watch this dude talk about anything. One day my shop will be like his i hope
this is the best channel since I found AvE many years ago. and thanks to this excellent video I have a newly found love and appreciation for Balsa wood! thank you!
Brian Boatright dead tree carcasses! 😀😀
Many years ago? Like, six tops?
Give a man sealed balsa wood and he’ll make a composite core structure for a day. Teach a man how to seal balsa wood and he’ll make composite core structures for a lifetime.
Absolutely love your work.
I am employed as a machinist/technician at Carleton University, Canada's premier university for mechanical engineering.
I am involved in a large variety of projects from aerospace, mechatronics to biomed and beyond. It just never stops and that's great!! :).
Your lab is fantastic...cozy and very cottage like. Seems like a good place to sleep. Ha Ha!
I am eager to watch ALL of your stuff and to see future vids as well.
I agree with some of the other comments regarding the music. Just doesn't fit the mood.
Wishing you the best.
With respect.
Ian
This is so cool. Why have I never seen this channel before? Great work guys and I love seeing the material experimentation for all of these projects. It's awesome that you guys do solid research for your projects rather than just throwing a bunch of stuff together hoping that it works out. Keep up the great videos!
Your channel is so wonderful. So educational. I am excited to try new things. Thank you.
Great video and explanation of how (sandwich) fillers work, and tradeoffs. Love the info on balsa. I have not used it yet, but this video has convinced me to get some to experiment with. I am working on a project which will require every lightweight construction technique I can come up with.
Thanks for putting this info up. Happy to have come across your video. I have been debating core materials for the last 6 months to use on a fire wall repair on my Lotus Europa. I had looked into Coosa board and Nida Core manufactured materials, but after your demonstration of the properties of end grain balsa I think I have a winner. I also appreciate the extra info on proper preparation with coating epoxy/micro balloons on the core to promote adhesion and reduce wicking.
Great way to avoid the balsa from sucking up a bunch of epoxy with the micro spheres. I assumed you were going to use a higher viscosity epoxy that didn't wick, but this is a far better solution. Really interesting channel, I just discovered it today and am looking forward to going through your videos.
I'm wondering if whipping air into it would achieve the same result?
I usually just use one resin, a very low viscosity infusion resin, and no additives.
To avoid excessive wicking I just brush on a Layer, wait until its geltime is reached and proceed.
With extremely spongy and sucky materials I do it twice if needed.
Tested it and in many cases it's lighter and stronger as well compared to other solutions, the bonding is way better.
Test pieces didn't delaminate/buckle or whatever, like they did with about any other method, the core material simply ripped apart.
And not just end grain Balsa, even with Baltic Birch, Acorn etc., Airex or XPS - the poor folks Airex - of course just crumbles no matter which way.
I believe it makes the core material an integral part of the composite structure, with a wet-in-wet layup on top of a "wood epoxy composite" instead of incorporating a failure point on purpose, and with the gradually decreasing epoxy content in the wood it seems to have an excellent load distribution.
It's rather hard to get the process perfectly repeatable though, a spray gun and metered amounts would be the least I guess. But as amateur or for one offs - who cares?
Try it! It's simple and you don't need any unnecessary additives.
Your channel is so beyond detailed. Thank you so much for the time you take to share your vast knowledge.
You have a incredible ability to teach with efficiency in doing so that astounds me,I genuinely hope you make good from doing these videos cause you deserve every bit
Great channel!! I started watching you laser videos but always enjoy your in depth explanations. Can't wait for the RF stuff ;-)
Every single time that I see one of your videos, I know I'll learn something new, and every single time I am amazed at how much information and details about a very specific subject you can deliver! Simply amazing
Thanks
Fantastic videos. Please consider sharing your material sources. I think you could do well with affiliate sales from your website; cross listed and/or indexed by technology, videos and kits. Sourcing is half the battle for breaking into new technologies. Great shop/studio!
Gosh! I've recently watched some of your more recent videos about resins, but only just realised the breadth of your expertise across a range of technologies.
This is all as impressive as it is meticulously explained.
Thank you!
Very cool, worked the aerospace industry for 30 years and seeing balsa core brings back memories, I also play with pulsejets so I’m looking forward to seeing the ideas for making yours more efficient. I’m burning 500cc/min to produce 12-18 lbs of trust. I’m high for the amount of thrust but don’t burn valves at any rate.
Thank you for the work you do on these videos. They have inspired my to research areas of science I wouldn't have otherwise. UA-camrs like you reinvigorate my passion for science.
Thanks!
Always nice to learn how others tackle a challenge.. good content ! Thanks for sharing !!!
You are my science guru. It seems as though every project I stumble into, you tie in as source material in some form or another. Thank you, and please, keep it up!
Sure.
Your children are so very fortunate to have you as their father,genetically and as a role model
Absolutely superb explanation of the whys and how’s for us amateurs!! Thankyou
Thank you for the inspiration once again for self study into material sciences.
Your videos are spot on, and you are a phenomenal teacher, not to mention i appreciate you trying to be precise with terminology. That really helps my searches.
I'm glad you're here. Thanks!
Certainly a wealth of knowledge . Much appreciated 👍
Boy did I get lucky finding this channel! I love it and have subscribed.
Another fantastic video! Loving this channel more and more. :)
I really appreciate the effort and care that you put into your videos. In this specific video, the background audio is really diverting my attention though. It made me stressed and unfocused.
You have made some great improvements in the video production of your more recent videos. Very glad to see these changes. :)
On the subject of how you explain and go about practical projects, I'm very impressed. Way to go!
Excited for all upcoming content. Thank you!
Thanks!
I've been a fan of composites for decades (used to sneak off to Jr. High school library to read up on what Bert Ratan was up to ) Thanks, informative.
Thank you so much for this video. I've been looking for something that will provide a core for S2 fiberglass for building battery boxes for electric sprint karting that are both light and very strong (especially impact) while also resisting heat. I had looked at a lot of foams and hexagon materials that are as you say, very pricey or not that rigid. This seems like the best of both worlds.
Thank you for all the incredible information. Learning a lot today.
Great, more incoming!
Thanks for all you do. Very educational.
I always wondered why boat decks had the little cubes of balsa. Now I know! I am so glad your channel got recommended by the algorithm!
Welcome!
Thanks for demonstrating. I grew up with an inventor and laminates were the majority of the process.
This is one of the best videos I've ever seen in my life - thank you, Sir, for taking time to educate us!
Very good video and I have subscribed. Epoxy resin to hardener ratios are commonly specified by volume. Using a scale is more accurate (especially with smaller batches), less wasteful and less messy. Some epoxy manufactures give alternate ratios by weight, others don't but you can calculate it if you can get the densities from the product data sheets. For the products I use 2:1 by volume translates to 100:46 by weight, and 3:1 volume is 100:32 by weight.
Awesome stuff! Love your videos.
Boy it'd be great if you made an update video on all your old projects. I want to hear about the APU and the armor and concrete!
It's good to see you making a video in my field of work, I would tend towards using a vacuum to pre impregnate the core when using epoxy, especially for balsa wood its ability to wick is astounding or even using a thickened isothalic resin which gives less working time but uses less material.
I have found pre sealing with the thickend epoxy works best if you can't get the surface sealed end grain balsa directly from Baltek.
For sure my favorite channel
That opening statement awnsered every question i have 😂 thank you
Thanks, I did not know that you could buy balsa as end grain panels, useful.
Quite!
Thanks a lot for this very informative video, appreciate the efforts
Hi and Thank you ! Super interesting. Like taking physics and chemistry which teachers always wanted to flunk me in though I liked them so much ! Yayyyyyy UA-cam and Tech Ingredients !!!!!!!!
Best demo on jet/fan propulsion I've seen. Great work on creating that hybrid too, I can see you machined most of those items... Impressive.
Thank you for sharing! I love the music too!
I really wish there wasn't music throughout the video.
your more recent videos are so much better.
I am very thankful for your channel.
Please keep making videos.
Thanks!
I've got some serious shed envy watching this :)
Thank you buddy , You have helped me
I clicked on this video and seen that it had a thumbs down and I never did such a thing,maybe a glitch? I wonder..I changed it to a thumbs up cause all your videos deserves a thumbs up for sure
Thanks for checking!
Like other channels we have also had viewers complain that they were involuntarily unsubscribed. UA-cam has been redirecting viewers away from original content creators and toward corporate sites beginning around 2016. As you say, this may be just a glitch...
Nice, like to see more on videos on composite core construction, there are not many videos on what you did, Thanks again
Thanks.
I realize this is an old video and you'll not read this but I must say that your explanation of the forces at the beginning was excellent. You said the top is under tension and bottom under compression, which is how the limbs of bows work. This year marks my 42nd archery season and I collect bows. It is interesting how different cultures solve these parameters.
The universe is what it is, it's up to us to work with it. That's engineering no matter what the application.
The very successful WW2 fighter bomber, the Mosquito, used a lot of balsa in its construction. Very good material, probably under rated in todays high tech world. Excellent video; I learnt a lot.
Thanks!
One of the most educational channels on YT. Priceless for the time spent.
I wonder if instead of filling the balsa with "nothing" (the micro spheres and the additional epoxy ) one would not get the same result by placing the mixed epoxy on the carbon fiber and laying flat the balsa on top letting them cure this way and then repeating the process for the other side. Some epoxy might capillary creep into balsa upwards but I doubt it to be too much.
Just a thought... Anyway, I have learned a lot from you, so... thank you and keep up the fun education for the rest of us.
Thanks!
The capillary action of the balsa channels will still draw the epoxy away from the carbon. The force of gravity is small by comparison.
@@TechIngredients Thank you! Another afterthought I had (after initial posting) was to lightly sandblast (or sandpaper) the carbon fiber creating some retention (wetting) A lot of fun anyway, thanks again.
Wow, so much useful information in one video 👌
Great video. Love all your great videos.
Hopefully if possible please do video on FLASH GRAPHENE or something similar. I am planning to build the required capacitor bank on the lines of Rice University experiment.
Great show!
Thanks interesting video. I’ve never even thought of using cross gain balsa, I like it
Len d I don’t think this is cross-grain balsa. That sounds like plywood. This is end-grain balsa. It is put together in small squares where the glued edges are the long grain, not the end grain. I think the manufacturers of sheets of end-grain balsa do this because one of the drawback is to this material is if the costing fails, in an underwater setting like the hull of a boat, or even on the deck, the balsa will wick water and saturate very quickly, and it rots very quickly. Making the sheet from small squares reduces how far and how quickly the water will migrate.
@@oddjobbobb The reason for using end grain balsa was explained early in the video with the bunch of straws, it has higher strength against bending when laminated.
Again a great video. I had no problems with the background music, but reading other comments, I think you could set the music volume to be slightly above "barely hearable".
My main motivation for this comment, though, is that I think one could be a little more 'lazy' and give the carbon fiber sheet a coat of epoxy, then wait until it started hardening but still "tacky", then add the Balsa; I believe the epoxy would not get too deeply into the Balsa then.
I also thought about the foam... popsicle+foam+popsicle+foam+popsicle ... this would only give you stiffness in one direction, though - however if you have no Balsa but a lot of foam and thin strips of wood, it could be an alternative to get lightweight stiffness. One could also use a bunch of thin strips to make a "torsion-box".
-Or if you have a bunch of corrugated cardboard (it can be acquired as "paper-ish" rolls), you could make sheets / rolls and slice them into boards using a cheap (large) handsaw - thinned PVA glue is usually fine for gluing cardboard sheets (eg. from box sides).
Awesome video and the music made it much more cheerful, alive and vivid.
Very interesting stuff, I like it. Wish you've shown strength of result composite though.
Another great video 👍. If you’d like the XPS to take a greater point load you can always try Owens Corning FOAMULAR 1000 😊
Excellent interesting video as always!.. Thanks.. I would love meet you and visit your lab!
VERY COOL!!! what a good idea
Thought it was called amorphous. Thixotropic, never heard of - guess you learn something new every day :) Thanks :)
Sure!
Perfect timing. I was about to buld a light weight structure.
I feel like this would be a very good application of stabilizing resin, apply it to balsa prior to carbon fiber application. Downsize is the cost and added weight, but you may see some significant increases in rigidity and hardness.
I always learn something new with your videos. Thank you :)
Great info!
Absolutely fantastic content! Also watched the 'Easy Tricks Using Fiberglass Strengthening!' and I could't stop. So much knowledge, thank you for sharing it! I came across your channel looking for a solution. I'm building a sit/stand desk with quite a bit of weight of equipment attached to it. I decided to reinforce it with two steel plates where I would place two heavy-duty monitor arms. The problem is that the plates added quite a bit of weight, so much so that there is much more stress on the rear legs than the front ones (it's a 4-legged frame, with 4 separate motors). This contributes to a significant wobble at the start and finish of the motors' operation.
Would you be able to recommend some kind of material I could use instead of the steel plates? It doesn't have to be the lightest possible (like balsa wood) but the steel in an overkill in this case.
Putting that epoxy on the balsa looked like spreading Nutella on a warm piece of toast! I must be hungrier than I realized. :-)
This is the best channel ever! A lot of these topics are things i'm quite familiar with so I always start watching this thinking i won't new anything new in terms of science but i might get inspired to try some new technique or whatever.. So far, i've never been right about the science part lol. The diversity of in-depth information keeps surprising me every time and its so impressive that your knowledge stretches out over such a wide range of expertise. Thanks again teach! keep em coming!
PS. Could you tell me if the tubular orientation in your piece of balsa wood is manufactured like that specifically for use as a hybrid composite core, or is it a typical characteristic of sheets of balsa in general (im referring to the panels i can buy at my local hobby shop, would they most likey be suitable for this application?)
cheers
Thanks for your kind words! Regarding the balsa, typical hobby balsa will not work. The tubular orientation is parallel to the surface in these boards. End grain balsa is specifically fabricated as a core material with its vertical grain orientation. It also makes for nice speaker panels if you have any left after your project.
Love this!
Thanks! More on the way and if you liked this, please subscribe. It really helps us out.
Brilliant, watched a few now but please loose any music in the background. You don't need it. Its wonderfully instructive. Thanks.
In aircraft a similar product is GLARE glass laminate aluminium reinforced extrusion. Strong as and light as.
Another one is a hexagonal aluminium sheet that’s about 10mm thick the hexagons are on the vertical axis and the aluminium is goddessly thin as in thin enough to easily slice your finger. And that honeycomb sheet has a GLARE top bottom and sides and is rigid in all dimensions with fantastic sheer strength. The GLARE outer layer is only about 1.2mm thick and has 2 aluminium layers between 3 glass layers. I’m sure there are more sizes but this is the one used at my work to make chart tables in the rear of our surveillance aircraft. They weigh less than the scales that measure them and can be stood on by an adult male. Well by you but not the average USA male these days.
The sheet structure comes in very large panels and you cut it to shape and add the edging. I haven’t done it myself but I have seen a damaged table top that had a corner gouged out be repaired and the engineer said that once the crushed edge was removed that you just re edge it like it was originally and it just as strong as before. And I watched him do that. I’m the captain so I’m responsible and it was interesting as all get out. And yes I bled all over the floor and my flight suit playing with the cutoff.
The air gap between the layers is sound muffling and the laminated faces reduce sharp sounds.
I learn something new every day! Thanks so much!
That is definitely useful. Thank you
You're welcome!
Agreed with respect to music, your presentation is adaquate, better than crappy music.
I've done this with boat repair. Used fiberglass rather than carbon fiber. West System sells the epoxy and a wide variety of fillers with various properties. If you look up boat repair you can get many good tips (and some bad ones).
You're right!
We're building a hydrofoil catamaran at this time. Stay tuned.
Brilliant!!!
My problem with balsa as a composite filler is largely the same as my problem with most composite filler: water intrusion. After some number of years, some point on a boat hull is going to develop a hole the size of a pin that allows water to contact the filler material. Thermal expansion/contraction will force water in. Most composite filler materials quickly start turning into structurally useless mush. And the mush spreads. Below the waterline there's no composite filler that really lasts. If you want a boat to last more than a few seasons you have to get an old boat from when nobody even tried to do fancy layered composites and they were made in solid (and yes, heavy) fiberglass all the way through.
A poor layup leaves behind microscopy air bubbles! Usually from working the fiberglass to fast. Yes, it can take on water over time and can cause severe damage!
Love your work mate! If I may offer one small piece of criticism, the music is really unnecessary (and honestly a little distracting)
Agreed, the content presented on this channel does not profit from background music. Better to leave that to the entertainment channels.
I agree but I also find the content entertaining , I will say trying to imagine technical content with music going for me is tough but I have a coworker that is the total opposite..
Make your own damn videos and stop whining.
I find it easier to concentrate on what he is saying with the music.
Audio quality is great and this low volume music makes the class more pleasing, keep it!
I read down quite a ways looking to see if my question was already asked, but I didn’t see it. I am curious why you don’t immediately lay at least a lightweight piece of glass in the thickened resin a soon as you have the balsa coated. I NEVER fail to learn from your videos.
I love your content! I would love to see what’s going on with that gas powered APU lately ;)
Pallets for military and commercial aircraft utilize two inch cross grain balsa and .040" aluminum. These are 8x8 foot pieces. Very little bending and very light. Only downside is corrosion. I'm thinking you built a composite aircraft (VariEze) or some other Rutan design. Nice work.
Outstanding presentation
Thank you!
Love the video, aweful music! ;)
Thanks for the nice video's! I watched a lot of them the last 2 days and learned a lot, I'm happy to have added you to my subscriptions list :)
A question about these core constructions, did you consider a 3D printed core? I am working on an RC paramotor at the moment and am using a composite core construction but in this case the core is made of printed plastic. The thing I like about it is that you are free to make more complex shapes and the shapes get replicated accurately. The internal construction of the printed parts can easily be configured to be optimized for the load you expect to put on it.
Welcome and thanks. We have considered 3D cores. The engineered strength and dimensional freedom are attractive. The relatively slow printing speeds, so far, are not. Nevertheless, it's only a matter of time before the 3D systems become fast enough and the material prices drop from proprietary to commodity.
Thanks for the answer! I understand that it is not even close to beeing an alternative in a production sense. I was mainly/only thinking about one-off jobs or small hobby runs as you are doing with these propeller blades. There are quite quick alternatives for FDM printers though, with large diameter nozzles and double heater elements that can make large shapes reasonably quick. it does require more sanding though to get the surface flat.
I recently discovered your channel and it's fantastic. You are very good at delivering technical information in a very accessible way.
With this composite video, it didn't address an issue that came up after I watched the video noted below. I'm trying to understand the interplay of differing materials used in composites used in surfskis The typical configuration is some combination of Kevlar, carbon fiber and nomex honeycomb. The properties of those materials seem to be at odds with each other. They also don't seem to address the common failure point just fore and aft of the cockpit when the surfski breaks through a wave and crashes down on the other side. There is a strong compression on the top and a strong tension force on the bottom. This would presumably cause Kevlar to fail at the compression side. Choosing a single material that is better at handling all forces compared to the darlings of Kevlar and Carbon would seem appropriate. That being S-glass. Can you point me to any sources I can investigate to get clarification? Thank you.
The missing link
ua-cam.com/video/KHXVf0SaJpA/v-deo.html
S glass is actually stronger than carbon and tougher than Kevlar. The downside is that it's significantly heavier. It works well in both compression and tension.
@@TechIngredients so do you prefer a single fabric on the outside layers or is a combination of materials, at locations
specific to their stresses with other beneficial properties like being lighter
For anything short of a very specialized competition design (expensive), keep it simple.
Raka same stuff I use, great stuff..
This topic was well presented. May I ask a few questions. NOTE, I ask these questions because I have not yet found any other site that discusses the weight (or specific density) of the end grain balsa that is sealed with any material and also provides the weight of the reference balsa that is unsealed. ~~ Have you or anyone developed an optimized sealer for balsa where the control (reduction) of weight is the primary objective? ~~ Can the phenolic spheres be measured by volume in order to simplify the formulation? ~~ When purchasing the end grain balsa, what density did you purchase and did you weight the balsa prior to your demonstration? ~~ What was the weight of the resin/phenolic mixture that you prepared and what was the remaining weight after you applied it to your sample? ~~ With a scale that can weigh materials to 0.01 grams, could the formulations be developed based on weight? ~~ How much weight of epoxy in the carbon fiber sandwich would be saved by sealing the end grain balsa? ~~ Are there any published sources for this information related material weight?
Those are a fair number of questions. We used the most common balsa density of 6.5 lb/cubic foot. The phenolic microspheres are the lightest available filler for thickening the epoxy. The approximate density of the thickened epoxy is 70% of the pure epoxy. The quantity used is variable and depends significantly on your application technique. Do not attempt to apply the cloth whether carbon or glass to unsealed balsa because the balsa will wick away the epoxy from the interface and prevent a good bond.
i found it fascinating
Thanks for the videos, I love seeing some productive content rather than recycled rubish! I am curious though, do you feel this would seal the balsa enough to prevent rot long term? I would be worried about any penetration (e.g. screwing something into a panel) that might cause rot later.
It works pretty well, but it still is a cellulose based material.
Regarding fasteners, bore a hole much larger than the screw all the way through the first skin and the core, but not through the second skin. Fill the hole with thickened epoxy and once curred, screw into this.
I love this channel! I keep ending back here for great DIY projects. I am watching this video as part of my quest to finding the best material for the DML loudspeaker you've also covered - have you considered testing the audio exciters on a panel of the balsa sandwich material? Or foam core carbon fiber panel?
Yes. The increased stiffness produced by the outer layer of cloth significantly reduces the sound output of the panels especially at the lower frequencies.
Great channel ! Super content. I was wondering what needs to be done to ensure the filled epoxy layer on the balsa adheres well to the carbon fiber layer? Sandpaper? flame ? plasma? THX.
Sandpaper works, but take a look at our later video on epoxy "Cheap and Strong" there is an easier, cleaner and stronger method.
So useful indeed
i like how you anthropomorphize the plate of metal
Just revisiting this video after rewatching the "Super Strong Epoxy with Diamonds and More!" video from 2020. Out of those materials presented, would you stick with the phenolic microspheres for this application? The thought is to build a lightweight plane wing so with the UV exposure, maybe one of the powders from that video (graphite, aluminum, dendridic copper) would also be a good additive. In this instance, it would of course only make sense using balsa wood vs a foam core since the foam can be used with plain epoxy.
Interesting. I wonder if this could be used to skin/wrap (for structural purposes) somewhat porous wooden guitar neck, leave it to dry until it's tacky and then apply different carbon fiber layers with additional normal resin? The idea would be to grain fill porous wood, so it's not to shallow and not too deep into the wood, and at the same time (without sanding stages in between) form better bond between wood, filler, carbon fiber and resin.
Balsa is not cheaper than foam in the northeast US. For example, 1" 4x8 XPS is about $20. By comparison, the same square footage of balsa 3/8" thick is about $120, and you probably have to pay shipping as well since it is not usually available locally.
Great video. Could you add reference as to where to get the materials including carbon fiber? This could help in getting support for these video from suppliers.
Ebay, Amazon, and your local search engine. :-)
I've found that when mixing epoxy if I mix it until well mixed, then put the contents into a new clean container and mix it some more I get a MUCH more consistent mixture.