Another great lesson I’m going to have to put a tv in my garage when I get my tig welder so me and my grandson can replay your videos while we’re learning thanks Greg you are the master.
Glad to hear you like it 😀👍. As things progress less and less time will be spent on the basics and a lot more time just on the welding aspects in the videos. I am making sure the whole series will build everyone’s skills from nothing up to functionally good. I will also do some advanced videos to help boost skills for seasoned people via challenges.
Such a helpful, instructional video. Explaining that the arc involves not just the very tip of the tungsten but a little bit along the length of it reveals why I can never see the very tip of the electrode. Also the color change indicating the arc lengths. The longer the arc length the brighter the arc. Many thx again,Greg! Most likely I am your oldest student at going on 82Years.
Glad you learned a bunch. Once you train your eyes/brain to interpret the light output to determine arc gap, tig becomes far easier. It takes a bit to build the muscle memory tied to what your eyes see, but it’s far easier than trying to look at the difference in a arc gap when your talking 64ths of a inch lol.
@@makingmistakeswithgreg This comment gives me some hope. I thought I was old, but John's like older than my father! I figured how can I learn to TiG weld, when even my own handwriting is sloppy, and my hands shake a bit... And I definitely don't have anywhere near perfect vision either. I had no idea the arc gap was only 1 mm, from watching a lot of other videos of TiG welding, I thought it was more like 1/8-3/32 of an inch which I know I can do that. The TiG videos I've watched are just welds not particulary teaching videos, but I was going by where the cone ends, I didn't realize the tip of the tungsten was down inside the arc, can't see the tip thru the ball of plasma on a lot of videos unless they're using something like a very high ND filter, or very fast shutter speed, and then the whole video would be complete darkness, except for a tiny arc cone.
Love all these videos!! Well you convinced me!! I pulled the trigger and ordered that esab 235- just hope my wife's not home when it shows up!! Also emailed esab corporate office told them they should contact you as your gaining alot of followers on youtube and you speak highly of their products!!
Thanks for the kind words and I am glad to hear you bought the same machine. I spent a lot of time to pick the 235 and it is in a pretty odd class of machine. I didn’t want/need a 300+ amp class machine but a normal 200 amp mig machine doesn’t have the power/duty cycle. The fact it runs 6010, uses the same foot pedal as other esab machines (if you haven’t bought a pedal but the SSC controls on eBay), and it doesn’t have the 70+ lb weight of many welders in the 250-280amp class makes it a real solid welder. I am sure you will be happy with it, and you won’t be short on power 😀
This series has been invaluable, I have watched it repeatedly over the last couple of weeks while waiting for black Friday to come and then for the welder and equipment to arrive and over the last 2 days of finally getting hands on and welding I have made massive progress in a short period. I did find a trick tonight that helped me a ton and I wanted to share, I had been changing my tungsten as soon as it got contaminated every time, finally I just said F* it, I'm gonna use this one to learn, I got it unstuck, fired an arc, took the torch and started playing with it, watching the arc, how it behaved, trying different things without worrying about contaminating the tungsten. Doing this I was able to figure out what the right arc looked like and once I ran a couple of beads with a dirty tungsten I took another crack at it running a bead with filler and the difference in my welds was incredible. I want to say thank you Greg, I appreciate the effort you put into your videos and the time you spent passing on your knowledge.
"Probably the greatest benefit of Tig welding is because your heat source is separate from your filler you're able to achieve very small high fusion welds that are much smaller than you'd ever be able to achieve with short-circuit Mig or stick." Learning here. I think this is helpful.
Glad to hear that 😀👍. If you think about it, tig is capable of making the most consistent fusion on a weld start to finish. Take a 1inch long weld on some part out of 1/2inch thick steel. If you were to weld it with mig/stick your start will have a lack of fusion 1/4inch from the actual start, this is mostly unavoidable. Tig (with an experienced welder) would not have this. Not to mention you are limited on weld size with other processes. Wire processes can only deposit so little of a weld before you can’t pass enough current to get fusion. The wire will become liquid and burn back. That’s why switching gasses to spray arc and running a different process is better for thick metal, but even then you’re still putting down big welds. Since tig is a heat source (and laser) they can achieve full root fusion separate of filler natal addition. I will have a full video demonstrating this soon.
I started tig welding recently and one thing I've noticed for a beginner, you can lay down the wire in front of the torch and just have the torch melt it as you move forward. However this requires you to understand your arc gap and travel speed well and also the geometry of the weld. I had a huge problem with walking the cup back and forth to weld fillet welds on coupons because you need to do the back and forth motion while moving the tig torch in the direction of the weld.
You can do the “lay wire” technique, but you must be careful that you melt through the wire and fuse the root. By pulling the wire out and pushing it in you can visually see the root fuse, keeping the wire in place you can’t. It actually takes a fair amount of amperage to do lay wire without a lack of fusion. Make sure to cut&etch your work to see what’s going on. As far as walking the cup, for a majority of what people do free handing is easier and functions better. It’s rare on a fabrication job I have done that walking the cup would have worked (you’re talking shorter welds with starting points that makes it impossible to walk from the start. Get good at weaving by hand first, trust me. Walking works really well on pipe, but pipe is not exactly common to what things most people weld on. Anyway, keep up the practice and welcome to tig welding 😀👍
Mr Greg it's great to see the content that you put out it also makes a great big difference in what style and what size of cup you're using too and the grind on your tungsten. Me personally my go-to on steel and stainless steel is my jazzy 10 cup I see as you're showing as a demonstration it looks like you're running either an 8 or 7 large gas lens with a 45° angle grind I like my grind at a 30° grind it gives me a better pinpoint on my cone why welding.
The #10 is a solid option, I can use less shielding gas with a #8, but if I had to pick one cup the #10 gives the best overall results. You can use a lot of different grind angles and believe it or not they will affect how wide of welds can be made. I will have to do a video testing that to find out how much a difference there is.
great lesson Greg, and really great shots. I can't wait to get started. I have almost everything ready, just need to get a bottle of Ar. Have you had any thought of someplace for folks to share pics of their progress?
Glad to hear you’re getting ready to start 😀. I am in the process of starting something for people to share pics. Because of my more limited time I am having someone help me with it. I would love to share pictures of peoples work/progress to help keep everyone motivated 😀
Great question. I will have a video on this in particular. It really comes down to joint configuration and material thickness. The key thing is you don’t want to produce a thin point in the joined pieces.
Some Plasma cutters has a stand off bracket , but we never see that on tig . Is it because it in most cases is impractical , or is it that tig is an art form not to be touched?
The only time something to hold a standoff would work is on flat butt welds, on things like inside corner joints you can actually use the cup itself to help hold a arc gap 😀
Making mistakes with Greg.. Getting back into TIG (welded for a living in the 90's) has been a little bit of a challenge for me. For some reason I just can't see puddle almost like the light is too bright or something. Stick and MIG welding is still on point. Just that dang TIG. LOL
Try a different helmet. I went through several that were fine for stick and mig but sucked for tig.My tig helmet sucks for stick. No matter the settings.
@@beyondmiddleagedman7240 Thanks I will have to try that. I have like 4 helmets. All I had back in the day was a normal flip shield/helmet so I didn't think it mattered. My eyes were a lot better back though so I thought it was my eyes now. I mean all I see with these auto-darkening helmets is bright light no matter the setting like you said. Thanks for the info.
What other people shared really sums it up. Some welding helmets are better than others. To me being able to see some color of the weld can make a big difference in knowing what’s going on. Most hoods with “4C” lenses are going to be pretty decent for tig.
One thing I hear many, many people talk about is the heat zone and how important that is. For stainless steel, I get it. For aluminum, too much heat and the metal can drop out. Steel? Never an explanation other than warping can be experienced. I have gas welded a motorcycle frame, drove in many miles in the dirt and even raced it about 3 times and tried to practice it often. The racing was in motocross and the bike saw many conditions. I know when I changed the peg location and how they were mounted, the steel was glowing more than any half a.. TIG weld. Can you possibly explain the importance of a heat affected zone with mild steels, 1045 steels and 4130 steels. 4130 would be the one that could cause the most failures but, no one explains why HAZ is important. If it is important, why is no one making videos about the topic?
For mild steel it really isn't short of melting it it's meant to be soft and bend. Heating something up and then letting it cool slowly will be at its softest state. Some tool steels or high alloy steels like 4130 are not supposed to be super soft theyve been heat treated to be a little bit harder. That's the issue you will ruin the strength. If you're welding it prior to the hardening process you will be golden. Also you have to think about diluting the chemical composition using welding wire that's meant for mild steels. There are specialty wires
I definitely will cover this in a future video, but here is some info for now: How welding affects a metal is completely dependent on the metal in question. Some metals have serious changes in the heat affected zone (chromoly, cast iron, tool steel, titanium, aluminum, etc). Other metals are mostly unaffected (stainless and normal mild steel). Now I am not a metallurgist but I know a lot about difficult to weld metals and what happens when you weld them improperly. There are some pretty hard set truths with them. Universally metals that are heat treated or tempered as part of the production they will have serious changes in the heat affected zone. Universally metals with high carbon content will become brittle during welding. Those two things can cause failures of a part of the changes are not accommodated for. Since you talked about chromoly in specific, the HAZ is where changes to the material happen. Chromoly is commonly welded with er70 and not straight chromoly/er80 because the failure of the welded part is in the heat affected zone and not the weld. Under welding it with a more ductile er70 tends to work better. Material under 1/4in is generally not considered thick enough to mandate a preheat, interpass limits, or post heat required. It is possible to weld chromoly with straight 4130 but it would be required to heat treat the finished part. Chromoly can be successfully oxy fuel welded because in a round about way you are slowly bringing it up to temp and slowly lowering the temp when it’s finished being welded. Chromoly (and many higher strength materials) do not like being brought to a hot temp and then allowed to cool fast. Aluminum has this “hot shortness” issue just like thicker chromoly does. Oxy fuel also will have a much wider heat affected zone, and likely have an annealing effect on a significant area near the weld. My guess is chromoly tube oxy fuel welded would have less rigidity (and possibly less strength) than a tig welded tube, but it would be less likely to crack/break when stressed. With that understood the reason many people don’t weld it properly is because they don’t understand how it should be welded. The reality is chromoly will never retain 100% of its unwelded strength unless it’s heat treated after welding. For the most part the loss in strength isn’t a huge issue. However it brings up a interesting issue: the cost of chromoly and the weight savings is often not worth it for many things because of its tendency to break and fail in undesirable ways that mild steel doesn’t. As far as conventional steel, the heat affected zone has minimal changes and is of little concern. Excessively hot welds on mild steel (aka a bunch of passes fast) produce poor grain structure that can’t be changed after the fact, but that strength loss is universal with all of welding.
@@makingmistakeswithgreg Can mild steel with poor grain structure be reheated to a very high temperature, say like to the point where it becomes nearly soft, like forging temperature, and then allowed to cool very slowly? I'm familiar with glass work, so glass blown pieces have to be reheated and then put in a tempering oven at like 900 degrees, and depending on if it's a big piece has to be cooled over even 24 hours. The bigger the chunk of glass, the more internal stresses there are to relieve or the piece can just explode after cooling. I've seen some stainless steels become very brittle from lots of heat cycle abuse to the point where it becomes dark grey and kind of crumbly like a dark grey cookie. One example that comes to mind is a large restaurant steam table that had a single long gas burner under the bottom. Well, they had repeatedly let the water evaporate and neglected to top off the water in it, and the stainless steel bottom becomes red hot. And then they dump in 4-5 gallons of warm water which shock cools it. Rinse and repeat, and the bottom was all warped and lots of big cracks and leaked. The stuff was so bad it was impossible to patch it or weld over it, so the only option was to cut out the whole bottom and replace it. Just for fun I hit the piece with a hammer, and it shattered into little crumbly grainy pieces. 300 series stainless steel sheet metal should never shatter even if you beat it hard with a hammer it should just make a dent.
@@makingmistakeswithgreg Thanks for taking the time to explain the chrome moly. I understand the change a 300 series stainless goes through and the HAZ effects. Very glad to hear you will be doing a video on HAZ. You have one viewer lined up already to watch it, me. Many videos I have watched talk able this topic when doing mild steel and it made me scratch my head. From playing with 4130 tubing and dabbling with airplanes, I know that it too can have issues with too much heat with the weld cooling to quickly. I will be using ER70-2 for the 4130 welds I have to make.
@@4speed3pedalsI also forgot to mention that heat affected zone in the case of stainless can be an issue. Oxidization of stainless steel reduces its corrosion resistance. When the stainless is over heated it can also be subject to “carbide precipitation” where the chromium more or less gets baked out of the molten/ solidifying material. For the most part the material isn’t weaker from a strength perspective like with say 4130. Titanium’s heat affected zone is a much bigger concern, if the hot material is exposed to oxygen it will become brittle and weak. So it oxides colors much like stainless but the colors indicate the material is compromised where is stainless color just indicates fairly harmless oxidization (unless it’s dark grey).
The tighter the arc gap the more focused the arc and the more penetration. Amperage will have the same effect. This is only to a point, tig doesn’t have much “arc force” aka it has no push behind the heat. Mig and stick both have more or less physical energy pushing molten metal into the base material. I will definitely do a video covering this in depth 😀
Great question. It’s primarily done on very thin material with a very tight fit up. There are many downsides to straight fusion welds. If there is any gap you can’t weld it. Producing a clean weld that isn’t just “undercut/underfill” is very difficult. Prime example would be fusion welds on exhaust pipe but welds will likely fail due to the thinning of the metal thickness. It can be done on lap welds fairly easily. In most cases you’re far better off adding filler.
Hi Greg. These lessons are just fantastic. You explain it in a perfect way that makes sense. Thanks matey.
Another great lesson I’m going to have to put a tv in my garage when I get my tig welder so me and my grandson can replay your videos while we’re learning thanks Greg you are the master.
Thanks for the kind words and I am glad the videos are helpful to you 😀
I really like how you’re breaking it down into the basics and focusing on one thing before moving on. The series is great.
Glad to hear you like it 😀👍. As things progress less and less time will be spent on the basics and a lot more time just on the welding aspects in the videos. I am making sure the whole series will build everyone’s skills from nothing up to functionally good. I will also do some advanced videos to help boost skills for seasoned people via challenges.
Such a helpful, instructional video. Explaining that the arc involves not just the very tip of the tungsten but a little bit along the length of it reveals why I can never see the very tip of the electrode. Also the color change indicating the arc lengths. The longer the arc length the brighter the arc.
Many thx again,Greg!
Most likely I am your oldest student at going on 82Years.
Glad you learned a bunch. Once you train your eyes/brain to interpret the light output to determine arc gap, tig becomes far easier. It takes a bit to build the muscle memory tied to what your eyes see, but it’s far easier than trying to look at the difference in a arc gap when your talking 64ths of a inch lol.
@@makingmistakeswithgreg This comment gives me some hope. I thought I was old, but John's like older than my father! I figured how can I learn to TiG weld, when even my own handwriting is sloppy, and my hands shake a bit... And I definitely don't have anywhere near perfect vision either. I had no idea the arc gap was only 1 mm, from watching a lot of other videos of TiG welding, I thought it was more like 1/8-3/32 of an inch which I know I can do that. The TiG videos I've watched are just welds not particulary teaching videos, but I was going by where the cone ends, I didn't realize the tip of the tungsten was down inside the arc, can't see the tip thru the ball of plasma on a lot of videos unless they're using something like a very high ND filter, or very fast shutter speed, and then the whole video would be complete darkness, except for a tiny arc cone.
Love all these videos!! Well you convinced me!! I pulled the trigger and ordered that esab 235- just hope my wife's not home when it shows up!! Also emailed esab corporate office told them they should contact you as your gaining alot of followers on youtube and you speak highly of their products!!
Thanks for the kind words and I am glad to hear you bought the same machine. I spent a lot of time to pick the 235 and it is in a pretty odd class of machine. I didn’t want/need a 300+ amp class machine but a normal 200 amp mig machine doesn’t have the power/duty cycle. The fact it runs 6010, uses the same foot pedal as other esab machines (if you haven’t bought a pedal but the SSC controls on eBay), and it doesn’t have the 70+ lb weight of many welders in the 250-280amp class makes it a real solid welder. I am sure you will be happy with it, and you won’t be short on power 😀
This series has been invaluable, I have watched it repeatedly over the last couple of weeks while waiting for black Friday to come and then for the welder and equipment to arrive and over the last 2 days of finally getting hands on and welding I have made massive progress in a short period.
I did find a trick tonight that helped me a ton and I wanted to share, I had been changing my tungsten as soon as it got contaminated every time, finally I just said F* it, I'm gonna use this one to learn, I got it unstuck, fired an arc, took the torch and started playing with it, watching the arc, how it behaved, trying different things without worrying about contaminating the tungsten. Doing this I was able to figure out what the right arc looked like and once I ran a couple of beads with a dirty tungsten I took another crack at it running a bead with filler and the difference in my welds was incredible.
I want to say thank you Greg, I appreciate the effort you put into your videos and the time you spent passing on your knowledge.
Another great educational video on TIG welding.
Thank you for this series! Looking forward to more!
No problem 😀👍
Thank u Greg we appreciate u God Bless u always🙏🏽🙏🏽🙏🏽
"Probably the greatest benefit of Tig welding is because your heat source is separate from your filler you're able to achieve very small high fusion welds that are much smaller than you'd ever be able to achieve with short-circuit Mig or stick." Learning here. I think this is helpful.
Glad to hear that 😀👍. If you think about it, tig is capable of making the most consistent fusion on a weld start to finish. Take a 1inch long weld on some part out of 1/2inch thick steel. If you were to weld it with mig/stick your start will have a lack of fusion 1/4inch from the actual start, this is mostly unavoidable. Tig (with an experienced welder) would not have this. Not to mention you are limited on weld size with other processes. Wire processes can only deposit so little of a weld before you can’t pass enough current to get fusion. The wire will become liquid and burn back. That’s why switching gasses to spray arc and running a different process is better for thick metal, but even then you’re still putting down big welds. Since tig is a heat source (and laser) they can achieve full root fusion separate of filler natal addition. I will have a full video demonstrating this soon.
Very Excellent Presentation. Thanks !!!!
No problem 😀👍
Realy nice and informating video! 👍👍👍
Glad you liked it 😀
Great job. Thank you
I started tig welding recently and one thing I've noticed for a beginner, you can lay down the wire in front of the torch and just have the torch melt it as you move forward. However this requires you to understand your arc gap and travel speed well and also the geometry of the weld. I had a huge problem with walking the cup back and forth to weld fillet welds on coupons because you need to do the back and forth motion while moving the tig torch in the direction of the weld.
You can do the “lay wire” technique, but you must be careful that you melt through the wire and fuse the root. By pulling the wire out and pushing it in you can visually see the root fuse, keeping the wire in place you can’t. It actually takes a fair amount of amperage to do lay wire without a lack of fusion. Make sure to cut&etch your work to see what’s going on.
As far as walking the cup, for a majority of what people do free handing is easier and functions better. It’s rare on a fabrication job I have done that walking the cup would have worked (you’re talking shorter welds with starting points that makes it impossible to walk from the start. Get good at weaving by hand first, trust me. Walking works really well on pipe, but pipe is not exactly common to what things most people weld on.
Anyway, keep up the practice and welcome to tig welding 😀👍
Mr Greg it's great to see the content that you put out it also makes a great big difference in what style and what size of cup you're using too and the grind on your tungsten. Me personally my go-to on steel and stainless steel is my jazzy 10 cup I see as you're showing as a demonstration it looks like you're running either an 8 or 7 large gas lens with a 45° angle grind I like my grind at a 30° grind it gives me a better pinpoint on my cone why welding.
The #10 is a solid option, I can use less shielding gas with a #8, but if I had to pick one cup the #10 gives the best overall results. You can use a lot of different grind angles and believe it or not they will affect how wide of welds can be made. I will have to do a video testing that to find out how much a difference there is.
great lesson Greg, and really great shots. I can't wait to get started. I have almost everything ready, just need to get a bottle of Ar. Have you had any thought of someplace for folks to share pics of their progress?
Glad to hear you’re getting ready to start 😀. I am in the process of starting something for people to share pics. Because of my more limited time I am having someone help me with it. I would love to share pictures of peoples work/progress to help keep everyone motivated 😀
Love the videos, may never use the info, but maybe I will.
Welding farm stuff, worked for NASA for 12 years - not doing that again!
Thank you!
No problem 😀👍
Greg, what situations would you employ fusion welding instead of adding filler?
Great question. I will have a video on this in particular. It really comes down to joint configuration and material thickness. The key thing is you don’t want to produce a thin point in the joined pieces.
Some Plasma cutters has a stand off bracket , but we never see that on tig . Is it because it in most cases is impractical , or is it that tig is an art form not to be touched?
The only time something to hold a standoff would work is on flat butt welds, on things like inside corner joints you can actually use the cup itself to help hold a arc gap 😀
Making mistakes with Greg.. Getting back into TIG (welded for a living in the 90's) has been a little bit of a challenge for me. For some reason I just can't see puddle almost like the light is too bright or something. Stick and MIG welding is still on point. Just that dang TIG. LOL
Try a different helmet. I went through several that were fine for stick and mig but sucked for tig.My tig helmet sucks for stick. No matter the settings.
@@beyondmiddleagedman7240 Thanks I will have to try that. I have like 4 helmets. All I had back in the day was a normal flip shield/helmet so I didn't think it mattered. My eyes were a lot better back though so I thought it was my eyes now. I mean all I see with these auto-darkening helmets is bright light no matter the setting like you said. Thanks for the info.
@@beyondmiddleagedman7240 What helmets do you use for tig, stick and mig?
What other people shared really sums it up. Some welding helmets are better than others. To me being able to see some color of the weld can make a big difference in knowing what’s going on. Most hoods with “4C” lenses are going to be pretty decent for tig.
@@jheissjr I have a Lincoln fixed shade, an auto darkening Matco helmet and two Yeswelder auto one
One thing I hear many, many people talk about is the heat zone and how important that is. For stainless steel, I get it. For aluminum, too much heat and the metal can drop out. Steel? Never an explanation other than warping can be experienced. I have gas welded a motorcycle frame, drove in many miles in the dirt and even raced it about 3 times and tried to practice it often. The racing was in motocross and the bike saw many conditions. I know when I changed the peg location and how they were mounted, the steel was glowing more than any half a.. TIG weld. Can you possibly explain the importance of a heat affected zone with mild steels, 1045 steels and 4130 steels. 4130 would be the one that could cause the most failures but, no one explains why HAZ is important. If it is important, why is no one making videos about the topic?
For mild steel it really isn't short of melting it it's meant to be soft and bend. Heating something up and then letting it cool slowly will be at its softest state. Some tool steels or high alloy steels like 4130 are not supposed to be super soft theyve been heat treated to be a little bit harder. That's the issue you will ruin the strength. If you're welding it prior to the hardening process you will be golden.
Also you have to think about diluting the chemical composition using welding wire that's meant for mild steels. There are specialty wires
I definitely will cover this in a future video, but here is some info for now: How welding affects a metal is completely dependent on the metal in question. Some metals have serious changes in the heat affected zone (chromoly, cast iron, tool steel, titanium, aluminum, etc). Other metals are mostly unaffected (stainless and normal mild steel). Now I am not a metallurgist but I know a lot about difficult to weld metals and what happens when you weld them improperly. There are some pretty hard set truths with them. Universally metals that are heat treated or tempered as part of the production they will have serious changes in the heat affected zone. Universally metals with high carbon content will become brittle during welding. Those two things can cause failures of a part of the changes are not accommodated for.
Since you talked about chromoly in specific, the HAZ is where changes to the material happen. Chromoly is commonly welded with er70 and not straight chromoly/er80 because the failure of the welded part is in the heat affected zone and not the weld. Under welding it with a more ductile er70 tends to work better. Material under 1/4in is generally not considered thick enough to mandate a preheat, interpass limits, or post heat required. It is possible to weld chromoly with straight 4130 but it would be required to heat treat the finished part. Chromoly can be successfully oxy fuel welded because in a round about way you are slowly bringing it up to temp and slowly lowering the temp when it’s finished being welded. Chromoly (and many higher strength materials) do not like being brought to a hot temp and then allowed to cool fast. Aluminum has this “hot shortness” issue just like thicker chromoly does. Oxy fuel also will have a much wider heat affected zone, and likely have an annealing effect on a significant area near the weld. My guess is chromoly tube oxy fuel welded would have less rigidity (and possibly less strength) than a tig welded tube, but it would be less likely to crack/break when stressed.
With that understood the reason many people don’t weld it properly is because they don’t understand how it should be welded. The reality is chromoly will never retain 100% of its unwelded strength unless it’s heat treated after welding. For the most part the loss in strength isn’t a huge issue. However it brings up a interesting issue: the cost of chromoly and the weight savings is often not worth it for many things because of its tendency to break and fail in undesirable ways that mild steel doesn’t.
As far as conventional steel, the heat affected zone has minimal changes and is of little concern. Excessively hot welds on mild steel (aka a bunch of passes fast) produce poor grain structure that can’t be changed after the fact, but that strength loss is universal with all of welding.
@@makingmistakeswithgreg Can mild steel with poor grain structure be reheated to a very high temperature, say like to the point where it becomes nearly soft, like forging temperature, and then allowed to cool very slowly? I'm familiar with glass work, so glass blown pieces have to be reheated and then put in a tempering oven at like 900 degrees, and depending on if it's a big piece has to be cooled over even 24 hours. The bigger the chunk of glass, the more internal stresses there are to relieve or the piece can just explode after cooling. I've seen some stainless steels become very brittle from lots of heat cycle abuse to the point where it becomes dark grey and kind of crumbly like a dark grey cookie.
One example that comes to mind is a large restaurant steam table that had a single long gas burner under the bottom. Well, they had repeatedly let the water evaporate and neglected to top off the water in it, and the stainless steel bottom becomes red hot. And then they dump in 4-5 gallons of warm water which shock cools it. Rinse and repeat, and the bottom was all warped and lots of big cracks and leaked. The stuff was so bad it was impossible to patch it or weld over it, so the only option was to cut out the whole bottom and replace it. Just for fun I hit the piece with a hammer, and it shattered into little crumbly grainy pieces. 300 series stainless steel sheet metal should never shatter even if you beat it hard with a hammer it should just make a dent.
@@makingmistakeswithgreg Thanks for taking the time to explain the chrome moly. I understand the change a 300 series stainless goes through and the HAZ effects. Very glad to hear you will be doing a video on HAZ. You have one viewer lined up already to watch it, me. Many videos I have watched talk able this topic when doing mild steel and it made me scratch my head. From playing with 4130 tubing and dabbling with airplanes, I know that it too can have issues with too much heat with the weld cooling to quickly. I will be using ER70-2 for the 4130 welds I have to make.
@@4speed3pedalsI also forgot to mention that heat affected zone in the case of stainless can be an issue. Oxidization of stainless steel reduces its corrosion resistance. When the stainless is over heated it can also be subject to “carbide precipitation” where the chromium more or less gets baked out of the molten/ solidifying material. For the most part the material isn’t weaker from a strength perspective like with say 4130. Titanium’s heat affected zone is a much bigger concern, if the hot material is exposed to oxygen it will become brittle and weak. So it oxides colors much like stainless but the colors indicate the material is compromised where is stainless color just indicates fairly harmless oxidization (unless it’s dark grey).
How is penetration increased and decreased in tig?
The tighter the arc gap the more focused the arc and the more penetration. Amperage will have the same effect. This is only to a point, tig doesn’t have much “arc force” aka it has no push behind the heat. Mig and stick both have more or less physical energy pushing molten metal into the base material. I will definitely do a video covering this in depth 😀
Looking forward to the video!
Hows it goin greg?
It’s going well 😀👍
Greg, what situations would you use fusion tig welding instead of using filler?
Great question. It’s primarily done on very thin material with a very tight fit up. There are many downsides to straight fusion welds. If there is any gap you can’t weld it. Producing a clean weld that isn’t just “undercut/underfill” is very difficult. Prime example would be fusion welds on exhaust pipe but welds will likely fail due to the thinning of the metal thickness. It can be done on lap welds fairly easily. In most cases you’re far better off adding filler.