Welding 4130

4130 welding should be it's own topic. Lets move the hornets nest here.

http://home.hiwaay.net/~langford/sportair/

http://www.tigdepot.com/faq.html

[chip hayden]

Roger,
that's an excellent website! thanks for posting it. chip

[TheOldOne]

Re: Welding 4130

Originally posted by Roger
4130 welding should be it's own topic. Lets move the hornets nest here.

http://home.hiwaay.net/~langford/sportair/

http://www.tigdepot.com/ought it better to try mofaq.html

Roger that's A very nice web page. Thanks for the information!

[airweld]

I've been a fan of Wyatts for a long time. I agree with just about everything he says about welding 4130. Let's hope the PWHT issue dies right here. But if you still have doubts, get some tubing and make some test specimens and see how they break. It's great fun and we all need more practice anyway. Post your results so we all can see. Thanks, Scott.

[chip hayden]

once again, Wyatt has an awesome site and has done considerable testing with 4130. i do believe though that thick sections and multi-pass welds of this alloy will show brittle microstructure if cooling rates are not slowed. i have seen this firsthand in the machinabilty of this alloy and a simple file nick test can prove this.
D10.8-96 AWS spec addresses this in saying 1/2" or thicker has 1300F pwht, and 250F for a preheat of any thickness of 4130 tubing.
now i realize a&p mechanics and builders don't often see this thickness, but tube clusters and welds in close proximity do generate internal stresses that may cause embrittlement. so i believe these types of situations deserve special consideration. chip.

[Roger]

I just noticed 2nd link in my original post was scrambled but link is now right.

http://www.tigdepot.com/faq.html

Wyatt in his fac uses, "Preheat to 100ºF to 125ºF to remove moisture from parent material." The magazine article at the first link doesn't say anything about preheat.
Wyatt's fac also address post weld stress-relieving.

[airweld]

All this talk about welding 4130 tubing makes me want to build an airframe. Anyone have an airplane project in the works? I've been working on a tri-pacer conversion, stretched, tailwheel, cargo door, spring gear, 200 sq.ft. of wing, and hopefully 200 hp. Something that you can put a whole moose in and still get off in 400 ft.

[chip hayden]

is the moose dead or alive?[sorry]

[airweld]

If I could train the moose to follow me home, I wouldn't need to bother with the airplane.