Note: These blowers were originally used on kids small home bouncy castles. Once the castle "pops" they generally get sold off cheap due to limited application. They are however perfect for a small wood or charcoal fired furnace or forge. Alternatively you could use a barrel vacuum that has blow function. Cheers Rob
Hi Tony. It's certainly very cheap for this much heat. The gas furnace probably costs about $6 AU for an equivalent burn. The wood furnace with blast air burns as clean as gas. Cheers Rob
Hi Nobby. I got started doing this many years ago because the aluminium prices in Oz are a total rip off as well. Plus wasting any aluminium is of no concern, and you can re-melt your mistakes ;) Cheers Rob
I live in Thailand and I made my furnace from a Thai BBQ and I use my shop vac which I can reverse the hose on so it blows, as my blower. I fuel it with the charcoal the Thais use in the BBQs, I also have a proper crucible I bought and it works a treat. I use it mainly for doing lost foam casting, and it was interesting to hear what you said about not overheating the aluminium, because I can at times get a lot of bubbles in my castings, which I have always put down to gases from the foam burning away trying to escape, but getting trapped. I have had some success reducing them by the way I set it up in the sand and the way I attach the sprue, to try and ensure there are no sharp corners for gas to get trapped in. Great video, and very educational. 👍
Hi. I have done a bit of lost foam casting and the main issue I had was that the scrap packing type poly foams I used vary in composition, and some are even fire retardant. I didn't have a gasing issue, but did get some black carbon deposits from the foam melting/not burning up 100%. Definitely keep your aluminium temperature as low as possible to prevent porosity. The hotter the molten aluminium, the more it will gas. It's pointless to keep heating when the ally is already molten ;) I'm glad you enjoyed the video. Cheers Rob
@@XynuduI started out with a very low-density foam, which burns away too fast and I now only use that for my sprues. Then I found a much denser version and it works much better.
Yes, foams do vary a lot, burn up differently, even though they look much the same. I must get back to messing with lost foam casting again and get it right. Wax casting also looks interesting. So many varied ways to cast stuff on the cheap :) Cheers Rob
@@XynuduJust to sign off on this one, I have a mate who works for a tunnel boring company in Bangkok and they have their own maintenance shop, just recently they scrapped a heap of old equipment and I got 12kg of cast aluminium for around A$35, bargain. 👍
The cheap (or already on hand) blower of choice here in the states is a shop vac (the little barrel with a turbine on top type vacuum cleaner). They move a good bit of air, and also do a fine job of cleaning up sawdust, drill chips, and all the other fine crud that eventually coats your shop, lol.
Yes, that would work fine. Even an old hair dryer. The more air through put the hotter the fire. I've seen people burn out tree stumps by blasting a set fire with a leaf blower. Forced air blast makes a BIG difference to the fire temperature. Cheers Rob
A two for one idea. Force the air and then clean up afterwards. I picked one up on sale at Walmart the other day for $19. Should have bought two now that I think of it.
the shop vacs in the US no longer have an outlet to attach a hose to to blow air. They have eliminated the outlet port some time ago. Hard to find one like that used
Thongs and shorts on only in the workshop after everything had cooled down. I had my usual steel cap leather work boots on while melting/pouring. The ally slug looks OK. I will be interested to see how it turns on the lathe. Cheers Rob
The cast did turn out well Colum. Second time around ;) Lesson worth learning, if the cast is a dud, second time around often removes the impurities (as in this case).Cheers Rob
Brilliant Rob 👍👍👍 There's me thinking your paint can furnace was your first one 🙂 Finding the right type of tin can is a bit of an art form. Sad bugger that I am I spent ages walking up and down the tin can aisle in my local supermarket examining the cans 🤣 As you know they are nearly all ribbed these days, which is fine if you intend to sacrifice them but no good if you want to reuse them. Then I found the tuna cans, smooth sided with pattern draft built in and the size matches my small crucible for quantity of aluminium, perfect. When cooled I just tap the bottom of the tin and the aluminium falls out! Cheers, Alan.
Hi Alan. I think those tuna cans are made of thicker metal as well ? Once you get the process right, casting aluminium round stock is pretty easy really. Big money saver. I have a completely different to my usual videos project in mind ATM and if it works I will video it. This round stock will be part of it. Cheers Rob
@@Xynudu Hi Rob. According to my digital mic the tuna cans are 12.5 thou wall thickness. Not sure if that is thicker, sounds about right for a can. Horses for courses. Your crucible is much larger so you'd need a t least a couple of the tuna cans I use. Looking forward to the mystery video. Cheers, Alan.
I like this idea for myself because I have woods on my property and access to all the free fuel I could ever need. Did you add any sort of flux to the aluminum to help prevent porosity?
No flux or de-gaser. Not necessay if you pour as soon as the alloy goes runny. The hotter the melt, the more it will gas. It'spointless to continue heating after the metal has already melted, but plenty of people do and struggle for fixes. I generally use old wooden pallets for fuel as they are often given away free and made of hard wood with no chemical treatments. Cheers Rob.
@@Xynudu thanks for the information! I haven’t done a melt yet but I’ve watched several videos (including several of yours) but this is the first time I’ve seen your wood fire and block setup. Have you shown this before and I missed it? I’ll definitely be doing this instead of building a propane furnace. I have all the oak I could ever want. I was thinking about doing a melt in a can and just leaving it to solidify and cutting the end with the dross off with my horizontal bandsaw. Do you know if the dross will stay on top as everything cools down? If you don’t know, I may give it a try to find out.
This method is a good and cheap no fuss intro to metal melting. I did this for a long time before I went gas. I have shown it way back. The only drawback is that it must be done outside and there's a lot of heat blast involved. I've never tried a melt in a can as you mentioned. The dross should stay on top as it cools (I think) . The two main things that determine how good the melt will be are (1) use good quality clean, non oxidised, ally to begin with, and (2) don't over heat the melt. Do that and you should get good results. Scrap aluminium car wheel rims are the best ally I've used. A simple brick furnace and blower will get you started. If you get the bug you can move on to insulated gas furnaces etc. Good luck. Cheers Rob
Hi Jon. I don't think so. I get similar results using wood or gas. It all comes down to technique. Gasing is only an issue at higher melt temperatures. I pour as soon as the alloy is runny. Plus if possible always pre-heat the mould to prevent metal chill and burn off any coating. I've tried all the recommended, so called, de-gasers and fluxes and come away very unimpressed. They generally cause more harm than good. Cheers Rob
Hi Jon. The gas fired foundry is much more convenient and you don't have to deal with so much heat blast. The gas unit actually doesn't cost a lot to run. Probably about $6 a melt of that size. Yes, forced air feed makes a HUGE difference, depending on volume of air added. Not hot enough to melt brass properly, but very close. Cheers Rob
No. As this is a mainly experimental project I just melted down some odds and sods I had laying about. I think it will work, but I'm not sure how difficult it will be. Cheers Rob
Note: These blowers were originally used on kids small home bouncy castles. Once the castle "pops" they generally get sold off cheap due to limited application. They are however perfect for a small wood or charcoal fired furnace or forge. Alternatively you could use a barrel vacuum that has blow function. Cheers Rob
Thanks for the advice!!!
You have done a good job explaining the process
That must be far more economical than using bottled gas to heat the furness. Works great, good demonstration Rob. Cheers Tony
Hi Tony. It's certainly very cheap for this much heat. The gas furnace probably costs about $6 AU for an equivalent burn. The wood furnace with blast air burns as clean as gas. Cheers Rob
Great job Rob. That lump of aluminium would cost a fortune here. Thanks for sharing. Cheers Nobby
Hi Nobby. I got started doing this many years ago because the aluminium prices in Oz are a total rip off as well. Plus wasting any aluminium is of no concern, and you can re-melt your mistakes ;) Cheers Rob
I have used an old cast iron frying pan. Works great if you only need an inch or two deep. Melt and let cool in same pan and drops right out.
That takes me back Rob. When I was about 11 or 12 I had a similar set-up I used to melt lead. I used a vacuum for the blower.
When I was a kid we melted lead for spoon fishing sinkers on the kitchen stove. Melts pretty easily. Cheers Rob
@@Xynudu Always nice to see a new video from you Rob. 👍👍
I live in Thailand and I made my furnace from a Thai BBQ and I use my shop vac which I can reverse the hose on so it blows, as my blower. I fuel it with the charcoal the Thais use in the BBQs, I also have a proper crucible I bought and it works a treat. I use it mainly for doing lost foam casting, and it was interesting to hear what you said about not overheating the aluminium, because I can at times get a lot of bubbles in my castings, which I have always put down to gases from the foam burning away trying to escape, but getting trapped. I have had some success reducing them by the way I set it up in the sand and the way I attach the sprue, to try and ensure there are no sharp corners for gas to get trapped in. Great video, and very educational. 👍
Hi. I have done a bit of lost foam casting and the main issue I had was that the scrap packing type poly foams I used vary in composition, and some are even fire retardant. I didn't have a gasing issue, but did get some black carbon deposits from the foam melting/not burning up 100%. Definitely keep your aluminium temperature as low as possible to prevent porosity. The hotter the molten aluminium, the more it will gas. It's pointless to keep heating when the ally is already molten ;) I'm glad you enjoyed the video. Cheers Rob
@@XynuduI started out with a very low-density foam, which burns away too fast and I now only use that for my sprues. Then I found a much denser version and it works much better.
Yes, foams do vary a lot, burn up differently, even though they look much the same. I must get back to messing with lost foam casting again and get it right. Wax casting also looks interesting. So many varied ways to cast stuff on the cheap :) Cheers Rob
@@XynuduJust to sign off on this one, I have a mate who works for a tunnel boring company in Bangkok and they have their own maintenance shop, just recently they scrapped a heap of old equipment and I got 12kg of cast aluminium for around A$35, bargain. 👍
The cheap (or already on hand) blower of choice here in the states is a shop vac (the little barrel with a turbine on top type vacuum cleaner). They move a good bit of air, and also do a fine job of cleaning up sawdust, drill chips, and all the other fine crud that eventually coats your shop, lol.
Yes, that would work fine. Even an old hair dryer. The more air through put the hotter the fire. I've seen people burn out tree stumps by blasting a set fire with a leaf blower. Forced air blast makes a BIG difference to the fire temperature. Cheers Rob
A two for one idea. Force the air and then clean up afterwards. I picked one up on sale at Walmart the other day for $19. Should have bought two now that I think of it.
That's a good price. I sometimes use this blower and hose to clean out the workshop when leaves blow in. It's a handy unit.
the shop vacs in the US no longer have an outlet to attach a hose to to blow air. They have eliminated the outlet port some time ago. Hard to find one like that used
The 20 litre wet and dry barrel type (Ryobi, DeWalt, Ozito etc) in Oz all still have a blower function.
Thongs out of the question Rob? Leather thongs ofcourse!
That was a magnificent result.
Thongs and shorts on only in the workshop after everything had cooled down. I had my usual steel cap leather work boots on while melting/pouring. The ally slug looks OK. I will be interested to see how it turns on the lathe. Cheers Rob
Rob
Thongs are either panties or bathing suit bottoms in the U.S. Got me there for a second.
@@Xynudu I'll be watching out for that episode.
That's the way I do it Rob, great video, keep'um coming..
It's also pretty neighbour friendly. Cheers Rob
Great to see this in action , nice cast👍
The cast did turn out well Colum. Second time around ;) Lesson worth learning, if the cast is a dud, second time around often removes the impurities (as in this case).Cheers Rob
Brilliant Rob 👍👍👍 There's me thinking your paint can furnace was your first one 🙂 Finding the right type of tin can is a bit of an art form. Sad bugger that I am I spent ages walking up and down the tin can aisle in my local supermarket examining the cans 🤣 As you know they are nearly all ribbed these days, which is fine if you intend to sacrifice them but no good if you want to reuse them. Then I found the tuna cans, smooth sided with pattern draft built in and the size matches my small crucible for quantity of aluminium, perfect. When cooled I just tap the bottom of the tin and the aluminium falls out! Cheers, Alan.
Hi Alan. I think those tuna cans are made of thicker metal as well ? Once you get the process right, casting aluminium round stock is pretty easy really. Big money saver. I have a completely different to my usual videos project in mind ATM and if it works I will video it. This round stock will be part of it. Cheers Rob
@@Xynudu Hi Rob. According to my digital mic the tuna cans are 12.5 thou wall thickness. Not sure if that is thicker, sounds about right for a can. Horses for courses. Your crucible is much larger so you'd need a t least a couple of the tuna cans I use. Looking forward to the mystery video. Cheers, Alan.
If it's a success it may get some air time :) Cheers Rob
Sorta reminds me of doing heat treatment in the woodfire, not ideal but works just fine if care is taken 👍🍺
I like this idea for myself because I have woods on my property and access to all the free fuel I could ever need. Did you add any sort of flux to the aluminum to help prevent porosity?
No flux or de-gaser. Not necessay if you pour as soon as the alloy goes runny. The hotter the melt, the more it will gas. It'spointless to continue heating after the metal has already melted, but plenty of people do and struggle for fixes. I generally use old wooden pallets for fuel as they are often given away free and made of hard wood with no chemical treatments. Cheers Rob.
@@Xynudu thanks for the information! I haven’t done a melt yet but I’ve watched several videos (including several of yours) but this is the first time I’ve seen your wood fire and block setup. Have you shown this before and I missed it? I’ll definitely be doing this instead of building a propane furnace. I have all the oak I could ever want. I was thinking about doing a melt in a can and just leaving it to solidify and cutting the end with the dross off with my horizontal bandsaw. Do you know if the dross will stay on top as everything cools down? If you don’t know, I may give it a try to find out.
This method is a good and cheap no fuss intro to metal melting. I did this for a long time before I went gas. I have shown it way back. The only drawback is that it must be done outside and there's a lot of heat blast involved. I've never tried a melt in a can as you mentioned. The dross should stay on top as it cools (I think) . The two main things that determine how good the melt will be are (1) use good quality clean, non oxidised, ally to begin with, and (2) don't over heat the melt. Do that and you should get good results. Scrap aluminium car wheel rims are the best ally I've used. A simple brick furnace and blower will get you started. If you get the bug you can move on to insulated gas furnaces etc. Good luck. Cheers Rob
@@Xynudu Thanks Rob!
Nice end result Rob, I wonder if there are any natural de-gassing properties from the wood combustion, that looks to be very homogeneous. Cheers, Jon
Hi Jon. I don't think so. I get similar results using wood or gas. It all comes down to technique. Gasing is only an issue at higher melt temperatures. I pour as soon as the alloy is runny. Plus if possible always pre-heat the mould to prevent metal chill and burn off any coating. I've tried all the recommended, so called, de-gasers and fluxes and come away very unimpressed. They generally cause more harm than good. Cheers Rob
That blower certainly makes this a much faster job Rob. What do you prefer, this method or the foundry?
Hi Jon. The gas fired foundry is much more convenient and you don't have to deal with so much heat blast. The gas unit actually doesn't cost a lot to run. Probably about $6 a melt of that size. Yes, forced air feed makes a HUGE difference, depending on volume of air added. Not hot enough to melt brass properly, but very close. Cheers Rob
Would like to see it turned up. What's the project?
Ha Ha. It may fail miserably, so I will stay quiet on it for now. It's different. Cheers Rob
@@Xynudu did you use alloy wheels ?
No. As this is a mainly experimental project I just melted down some odds and sods I had laying about. I think it will work, but I'm not sure how difficult it will be. Cheers Rob