How do you think they made the hinges?

[mhorowit]

Re: Welding/repairing 4130

Mike, try to open this link and select the clip regarding working with 4130 chromoly. Dick

Good flick - thanks. Wish there were more discussion on how he got to the OTHER side of the longeron to continue the weld.
Also, he had to use a spreader to get the correct distance between station marks, so wasn't the structure under stress when he finished the weld? - Mike

[high time cub]

Re: How do you think they made the hinges?

Mike,
As you finish the weld, always bring the heat in that area down slowly in order to normalize the 4130. This will help reduce any built up stress.
Never allow a cool breeze or fan to blow on the parts being welded.
Jim

[mhorowit]

Re: How do you think they made the hinges?

Mike, you need to purchase a copy of the EAA's book:
"Aircraft Welding"
The ISBN is: 0-940000-49-0

Dick

And here's the jig (page 27) I built from the book - Mike

[flyguy]

Re: How do you think they made the hinges?

Mike,
I'm not a real expert, but that looks like a pretty good piece of tail to me.
DC

[mhorowit]

Re: How do you think they made the hinges?

Mike,
I'm not a real expert, but that looks like a pretty good piece of tail to me.
DC

Thanks, but although I'm very pleased with what I did, I know the welds could me much prettier, but I know how to improve that. I had a break from everything right after Katrina (I have some property in Biloxi) and my welding seems to have deteriorated. - Mike