Video series on TIG welding thin wall aircraft tubing

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1Bad88

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I just looked up my nearest EAA tech counselor to see if someone local can give me some welding pointers. The closest is Leonard Millholland.
 

Little Scrapper

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Tig brazing, 1/8” Silicon bronze, Argon, amp setting 105, 3/32” tungsten on 1/8” mild steel.

I made a new table for my 48” Tennsmith brake. Every once in a while I use this process because it’s about 2x faster than using steel filler and strength isn’t life or death. My Tig is always set up ready to go with a flip of the switch and Tig brazing is just a matter of grabbing the filler and let r rip.

Obviously I could have used RG45 or something else but Silicon bronze is just flat out fun. It’s been well over 2 years since I Tig Brazed (not to be confused with gas brazing and capillary action) so I was looking forward to this.

A big benefit to Tig Brazing with Silicon Bronze is you don’t need the heat like you would with steel type fillers (look at my amp setting). That means a lot less warping and a lot less jigging. I built this with zero jigs, I just built the legs and clamped it together, leveler it and got to work. Zero warping. Very fast. Big fat smooth welds that lay down rapidly is a fun process. 056AE9A8-65BD-44AE-B157-B90289CEA7D8.jpeg352CB419-9A3D-4D5A-B4A0-EFB625EA1C9E.jpeg2A21477F-8A3A-4F0E-8E05-C827DCC0F1A5.jpeg

If you do this don’t experiment with a airplane, build shop stuff with it instead and treat this process as something fun to do. In the real world of airplane building stick to the fillers I mention in all my videos.
 

Fiberglassworker

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Everdure silicon bronze is great stuff for brazing frames and joining galvanized parts , don't get it near 4130 unless you can live with the reduced strength.
 

Little Scrapper

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To avoid running another thread, what filler rod is best for gas welding of 4130, ie can you get 4130 filler rod ?
and can MIG be used just to tack a joint prior to gas welding, I have no TIG available at present. thanks .
I have a complete video series here in this thread that outlines that question with 100% clarity.

The quick version is you can use whatever you want from RG 45 to 70s2 etc. Experience tells you what to use based on your welder, style, preference etc etc.

For .035” I personally prefer a roll of mig wire and just cut 10’ pieces off the roll. .035/.040 in diameter 70s2 mig wire is how I built my Baby Ace fuselage. TIG process with MIG spool wire. To me it’s ideal.

And yes, you can tack with mig but I’d urge you not to do it. I would gas weld or buy a TIG machine and practice because there’s a ton of welding to do so do it right from the start.

Good luck.
 
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subnoize

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To avoid running another thread, what filler rod is best for gas welding of 4130, ie can you get 4130 filler rod ?
and can MIG be used just to tack a joint prior to gas welding, I have no TIG available at present. thanks .
Never use 4130 rod with 4130. Especially on aircraft. It will make a brittle weld that will crack quickly.

I recommend ER70S-6. Less splatter and less prone to cracking.

Lastly, you do not have the facility's to "normalize" anything much less metal. Watch this video instead;

Best of luck! Gas is very hard to do right but once you master it you will be better at all of the other processes.
 

Geraldc

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Never use 4130 rod with 4130. Especially on aircraft. It will make a brittle weld that will crack quickly.

I recommend ER70S-6. Less splatter and less prone to cracking.

Lastly, you do not have the facility's to "normalize" anything much less metal. Watch this video instead;

Best of luck! Gas is very hard to do right but once you master it you will be better at all of the other processes.
For those without the time to watch this the main points I got are.
Use the recommended filler rod .In the video ER80xx .
ER70-s6 is slightly weaker.
There has been a lot of discussion about heat treatment and post heat .
Presenter advises not to post heat.
Was a long video but I am in lockdown.
 

reo12

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If all the prior discussion didn't get one thinking that the world is full of opinions - here is discussion on an EAA forum. Note that while MIG wires can be used - they may not be ideal for the application.
ER70S6 vs RG45
 

Little Scrapper

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If all the prior discussion didn't get one thinking that the world is full of opinions - here is discussion on an EAA forum. Note that while MIG wires can be used - they may not be ideal for the application.
ER70S6 vs RG45
I’m confused by your post. MIG wire is just filler in a roll vs a stick, it’s spool wire. Designation of the filler wire itself is what matters not that it’s in a roll. Industry has done this for years and will continue to do so in the future because it’s efficient in certain applications.

MIG process? I’d never do it on thin wall 4130 as long as I’m capable of TIG welding. The problem here is people are cheap and want to talk themselves in to crappy machines and just get by. Fortunately those people almost never build a fuselage, they just talk about it on forums. The gold standard will always be Gas or TIG.

As far as filler type there’s zero data on airplane accidents pointing to filler used. So, it comes down to a bunch of amateurs arguing about made up facts.

I have welded with most of the popular filers and they all work great behind a competent welder / operator who understands penetration etc. 70s2 and 80s2 is my personal favorite but that’s only because I own a ton of it and use it all the time. Most amateurs don’t know the difference unless they do it for a living.

At some point actual data from issues that exist in the welded homebuilt aircraft hobby should be the reason to choose. I don’t know of any data that exists, if it does I’d love to read about it. Most of these welded designs were designed when RG45 was THE official material and they work great. 100 years of welding data and nobody mentions we have the answers and they are simple and available.

When data doesn’t exist and people are confused the answer to these questions is quite simple. Either follow the popular choice or weld samples and do destructive testing.

In one of my videos I talk about a sample joint that was intentionally welded horribly and then destroyed it. I intentionally did everything wrong I could. It held up fine. That’s the reality. Few people are willing to do this. I do it, film it and talk about it.

Most people overthink this stuff instead of actually practicing. It’s like they are afraid to practice and test. It’s unfortunate really.
 
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misterpeter

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I’m confused by your post. MIG wire is just filler in a roll vs a stick, it’s spool wire. Designation of the filler wire itself is what matters not that it’s in a roll. Industry has done this for years and will continue to do so in the future because it’s efficient in certain applications.

MIG process? I’d never do it on thin wall 4130 as long as I’m capable of TIG welding. The problem here is people are cheap and want to talk themselves in to crappy machines and just get by. Fortunately those people almost never build a fuselage, they just talk about it on forums. The gold standard will always be Gas or TIG.

As far as filler type there’s zero data on airplane accidents pointing to filler used. So, it comes down to a bunch of amateurs arguing about made up facts.

I have welded with most of the popular filers and they all work great behind a competent welder / operator who understands penetration etc. 70s2 and 80s2 is my personal favorite but that’s only because I own a ton of it and use it all the time. Most amateurs don’t know the difference unless they do it for a living.

At some point actual data from issues that exist in the welded homebuilt aircraft hobby should be the reason to choose. I don’t know of any data that exists, if it does I’d love to read about it. Most of these welded designs were designed when RG45 was THE official material and they work great. 100 years of welding data and nobody mentions we have the answers and they are simple and available.

When data doesn’t exist and people are confused the answer to these questions is quite simple. Either follow the popular choice or weld samples and do destructive testing.

In one of my videos I talk about a sample joint that was intentionally welded horribly and then destroyed it. I intentionally did everything wrong I could. It held up fine. That’s the reality. Few people are willing to do this. I do it, film it and talk about it.

Most people overthink this stuff instead of actually practicing. It’s like they are afraid to practice and test. It’s unfortunate really.
I agree entirely and while I spend my time TIG welding stainless, the same techniques and ideas apply with chrome-moly or any other metallic materials if approached sensibly :) Interesting in your series is the no-**** approach and your honesty about the access problems with or without a welding helmet on! I was just wondering… welding inside the ‘birdcage’ is a real pain, but surely some of the difficult bits on ‘bulkhead’ positions could be, with a bit of planning, be pre-welded as an assembly and then welded in to the sides/top/bottom sections of the fuselage (where the access problems are at least partly closer to the outside of the build)? My only experience with chrome-moly tubing is with bikes, where everything gets soldered. I have just ordered a set of drawings for a cub, so my welding expertise is about to get a new angle (or two) added to my present repertoire… Keep up the good work! Peter
 

Little Scrapper

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I agree entirely and while I spend my time TIG welding stainless, the same techniques and ideas apply with chrome-moly or any other metallic materials if approached sensibly :) Interesting in your series is the no-**** approach and your honesty about the access problems with or without a welding helmet on! I was just wondering… welding inside the ‘birdcage’ is a real pain, but surely some of the difficult bits on ‘bulkhead’ positions could be, with a bit of planning, be pre-welded as an assembly and then welded in to the sides/top/bottom sections of the fuselage (where the access problems are at least partly closer to the outside of the build)? My only experience with chrome-moly tubing is with bikes, where everything gets soldered. I have just ordered a set of drawings for a cub, so my welding expertise is about to get a new angle (or two) added to my present repertoire… Keep up the good work! Peter
I covered this is depth in one of my videos, I believe I did this with my wife in a video too. My videos are based on my experience over a 35+ year timeframe. It’s not the only way, it’s just my way. Inside the fuselage welding those hard to reach clusters is actually not hard at all. You will have no problem with this.

I use a sock hood with goggles and a special Gold Lens which is really a awesome lens by the way. Then I slide in. 2+ diopter magnifying lens. It’s quite the set up.

Please don’t sweat this stuff. Seriously, you’re gonna do great! Think of it this way, In order to end up with a hard to reach cluster you would already have hours of experience getting to that point in your fuselage of building the sides, bending, joining them, putting in the intercostals etc. So, by the time you get to that hard to weld inside cluster you’re gonna be a boss at this.

Just start. Just build that fuselage table and start! Wanna know what real confidence is? It’s knowing that no matter what, you’re gonna figure it out and not quit. That’s what real confidence is. So make that agreement with yourself and just start.

On the Cub. Personally, I would build a small portable table on wheels in a small area and build all the sub components first. Spend 6 months building the fittings, the tail group, the rudder pedals, the control stick etc. By the time you get to that fuselage you’re gonna be a Ace! You just will by great at it by default. And because all these components are already built the fuselage is gonna come together fast.

Lastly, if you do struggle at all it’s real simple. Just let me know. I’ll stop what I’m doing and make a video for you and build or show you how I might personally approach it. I have nothing to hide and love showing people how to fabricate from steel. I don’t just write things, I do it and film it live with zero editing. But I do it my way and my way isn’t the only way. There’s many ways that are better than mine and you may discover that you have ways that are better. But you don’t know this unless you start.
 

misterpeter

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Every journey, however short or long, begins with the first step out of the door… I have every confidence that I can do it - the welding will be the least of my troubles (and with a helping hand now and again, what could possibly go wrong!). I am 65 and have a 1year old who is aircraft mad! I hope I live long enough to finish it for him ( or one of the other 5 kids!). Interesting, I’ve never used goggles to TIG… I use a fantastic Swiss helmet that on or off allows me to differentiate even coloured objects. No use for the tight stuff, of course :) And thanks for your offer of help - I might well come back on that. I Used to fly quite a lot in Australia, but now in Germany my license is invalid and elapsed anyway. The biggest single-engine that I flew was an AN-2 in Ukraine, but the most fun was a 450hp Stearman in Adelaide. Ah, those were the days! Taildraggers are real fun! :) Peter
 

Little Scrapper

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Every journey, however short or long, begins with the first step out of the door… I have every confidence that I can do it - the welding will be the least of my troubles (and with a helping hand now and again, what could possibly go wrong!). I am 65 and have a 1year old who is aircraft mad! I hope I live long enough to finish it for him ( or one of the other 5 kids!). Interesting, I’ve never used goggles to TIG… I use a fantastic Swiss helmet that on or off allows me to differentiate even coloured objects. No use for the tight stuff, of course :) And thanks for your offer of help - I might well come back on that. I Used to fly quite a lot in Australia, but now in Germany my license is invalid and elapsed anyway. The biggest single-engine that I flew was an AN-2 in Ukraine, but the most fun was a 450hp Stearman in Adelaide. Ah, those were the days! Taildraggers are real fun! :) Peter
You have a great attitude, you’re gonna have lots of fun!
 

misterpeter

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You bet! Since I’m not anymore only welding, but now also Laser-cutting at work (4kw laser, so up to 10mm stainless…), maybe I’ll be able to make a few custom parts for myself, too :) Shame about my commercials going down the Swanee, maybe I’ll manage a German ultralight licence yet! All the best, Peter
 

Little Scrapper

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@ misterpeter

You mentioned you have solid experience TIG welding stainless. That’s actually gonna help you big time, A good stainless welder is a hellova skill. You’re gonna kill this 4130, it will be like nothing for you.

I’ll dig up a photo for you of a stand I made when I built the Cassutt fuselage that helped me get in tight areas.
 

Little Scrapper

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@ misterpete

You mentioned tight areas. Cassutt’s are tiny inside. This was how I welded the inside clusters when I needed6E66E399-6B58-404C-AA96-EE0D09F7C6D5.jpeg560B3C94-9732-43BF-A120-E0F294F02BA1.jpeg it. I took some aluminum angle and drilled some holes and cut the webs. Halfazzed mounted it on a stand at a angle that would’ve tip. This allows me to hook on anywhere I needed at funky angles.

Man, it was so dam tight I couldn’t wear a hood so needed to get creative and wore a painters sock over my mellon and work goggles with lenses as described. It worked pretty good!
 

misterpeter

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The stand looks good :) I spend a lot of time fuse-welding (no filler!) 1mm to 5mm at 90 degrees and a fair amount of ‘hygienic’ welds for hospitals with gas on both sides or inside and out for tubing (mostly for distilleries). Ah well, gotta do something for a living, eh! Germany is a desert for home builders and the paperwork will be horrendous…
 

Little Scrapper

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The stand looks good :) I spend a lot of time fuse-welding (no filler!) 1mm to 5mm at 90 degrees and a fair amount of ‘hygienic’ welds for hospitals with gas on both sides or inside and out for tubing (mostly for distilleries). Ah well, gotta do something for a living, eh! Germany is a desert for home builders and the paperwork will be horrendous…
Think of it as a adventure abroad and you’re voluntarily gonna do the hardest thing possible in a foreign country with no resources. Haha. Imagine the hero status you’ll have if you get this figured out! 😂
 
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