Welding 4130

[kg4enb]

While waiting on my plans to come in I decide to research welding 4130. Now I am experienced at mig and stick on mild steel and aluminum, castiron.

Here is a video on the metallurgy of welding 4130. I found it interesting and thought I would share

[aeroplain2003]

The metallurgy is interesting, but what Mr. TIG is missing is that many builders of airframes are not expert welders, far from it. What he also doesn't say is what method of welding the welder at Osh. was using. I LOVE TIG, but if the heat affected area is to brittle for the rigors of flight, and performed by an amateur and my "Minnesota Mosquito" breaks, I might wish that I annealed. Just my opinion, and we all know about opinions.

Kent

[Bugsmasher]

I hate to say this....but I can't stand this guy at all.
I want to see his welding. I fly what I weld...and others as well. From a mechanical engineering background and pending weld multi-process certification I feel I have to speak out here to keep someone in a safer train of thought. Use ER70-s2 filler on molly. Period. If you use ER80 whatever it will need post weld stress relief to balance/maintain the levels of chromium and silicon in the parent metal and weld pool if it is 4130 CrMo. This is done in a controlled oven...not a torch. Most community college classes for welding will test a coupon for you. Just be honest/nice and explain what you are doing. There are a ton of things to go wrong with any weld process....even some early Piper J-2 and J-3's were stick welded! The new Champion airplanes are MIG welded !Most of the time 3 things go wrong in TIG welding. Torch too close or too far from weld puddle. Torch angle wrong. Filler wire taken out of the shielding gas cone while welding. You tame those and you'll go far.  The thing that bugs me is the Mr Tig never mentioned that the tubing was said to be from china. Who knows on that part. I would be more than happy to help anyone with welding this type stuff. I would even be willing to submit test coupons of my work for you to test. Sorry to rant on...but that touched a nerve.....Patients and willingness to learn whatever process you feel comfortable with {afford} is what I would weld with. A torch even welds when the power is out......these skills will make TIG an easy jump. I weld most all aircraft tube at 100 amps on the machine.....the weld puddle will show you all you need to know....even 1/4 x .035 wall. Learn to use the foot pedal amperage control. There is a wealth of knowledge to be gained here......        http://www.weldingtipsandtricks.com/tig-welding-heat.html                 Jody is a great guy to share a lot of good arc shot videos.

There are tons of TIG welded airframes flying all around the world.....most are home built. Absolutely nothing wrong with TIG as long as some instruction is taken on the fundamentals. But this is just me and my opinion...YMMV

[kg4enb]

Thanks Bugsmacher.
 I was trained stick and mig in high school, little bit pipe training in college and worked a few years in a full fab shop. but nevered touched tig. Back when I was coming up tig was for the local nuclear power plant, NASA, Racecars. I guess that is where  mystic of tig started for me so I stayed away.
 Yes I found Jody and I have been soaking up all I can. 
 EAA is having a tig fuselage class @ $400 in October down in Georgia I think I might sign up for it but I could just use that money and get a Tig setup and just start practicing.   
  By the way nice weld

[aeroplain2003]

This is what I wanted to here. I TIG all the time for work (alum welding on boats) and want to TIG my air frame, but have heard so much "fuss", I bought a torch. TIG makes so much sense to me for air frames for a less heat affected area, and major control of the weld to produce a high quality, and safe, union of the tubing.
Jody, of weldingtipsandtricks, is one of the best, and raised my skill level with his info.
Thanks Bugsmasher!!

Kent

I hate to say this....but I can't stand this guy at all.
I want to see his welding. I fly what I weld...and others as well. From a mechanical engineering background and pending weld multi-process certification I feel I have to speak out here to keep someone in a safer train of thought. Use ER70-s2 filler on molly. Period. If you use ER80 whatever it will need post weld stress relief to balance/maintain the levels of chromium and silicon in the parent metal and weld pool if it is 4130 CrMo. This is done in a controlled oven...not a torch. Most community college classes for welding will test a coupon for you. Just be honest/nice and explain what you are doing. There are a ton of things to go wrong with any weld process....even some early Piper J-2 and J-3's were stick welded! The new Champion airplanes are MIG welded !Most of the time 3 things go wrong in TIG welding. Torch too close or too far from weld puddle. Torch angle wrong. Filler wire taken out of the shielding gas cone while welding. You tame those and you'll go far.  The thing that bugs me is the Mr Tig never mentioned that the tubing was said to be from china. Who knows on that part. I would be more than happy to help anyone with welding this type stuff. I would even be willing to submit test coupons of my work for you to test. Sorry to rant on...but that touched a nerve.....Patients and willingness to learn whatever process you feel comfortable with {afford} is what I would weld with. A torch even welds when the power is out......these skills will make TIG an easy jump. I weld most all aircraft tube at 100 amps on the machine.....the weld puddle will show you all you need to know....even 1/4 x .035 wall. Learn to use the foot pedal amperage control. There is a wealth of knowledge to be gained here......        http://www.weldingtipsandtricks.com/tig-welding-heat.html                 Jody is a great guy to share a lot of good arc shot videos.

There are tons of TIG welded airframes flying all around the world.....most are home built. Absolutely nothing wrong with TIG as long as some instruction is taken on the fundamentals. But this is just me and my opinion...YMMV