Thread 1540122

I asked this on diy but the board is slow so I'm not getting any responses
https://www.amazon.com/FEMEROL-Welding-Portable-Inverter-Synergic/dp/B0F1K4G6R7
I'm trying to weld two tubes together, butt to butt with one overlapping part of the other like pic rel, and one is made out of 4140 and the other is mild steel due to it being the only material available in the specific size
I have 0 experience welding but I know somebody who does (but their welder no longer works so I need to buy a new one)
what I understand is that I have to heat up the 4140 section (I have a gas forge or a propane torch available to use, am open to rigging something up if the soot would be an issue)
and it can't warp or anything, I'm hoping it wont be an issue anyways since the mild steel tube is 3mm thick and the 4140 tube is significantly thicker but i can never be too safe
>just hire somebody to do it
it's for a gun receiver, not illegal to do myself or with a friend, I just can't pay somebody to do it for me
if its impossible to do with the mild steel tube just tell me, but it would mean a loss of $240 worth of machined metal

also the red part is the area that would be welded, it can have as big or small of a gap as it needs, I have more material on the mild steel tube than is necessary so I can grind it down to keep the dimensions correct

>>1540122 (OP)
Try >>>/k/

>>1540124
none of those retards have actually made or shot a gun in their life before
and its a question specifically for somebody who's good with welding, most people making guns don't weld

>>1540122 (OP)
You are overthinking every aspect of this project

With a Tig torch you can weld mild steel to tool steel. Just run the torch over the tool steel until it melts, and let the heat of the molten metal melt the mild steel.

But I would not try a weld like this as a first time welder on a $240 custom machined product. Find another solution

>>1540152
>Find another solution
there really isnt any unless you think a bit of solder will work, but i can practice a shit ton atleast

>>1540158
actually, would brazing work? the way this receiver is designed is that the bolt that travels inside of it absorbs most of the recoil and is slowed down by a strong spring, so really the connection only has to be as strong as if they were threaded to eachother

>>1540160
>, so really the connection only has to be as strong as if they were threaded to eachother
Now you're getting somewhere.

Cut your losses and go back to the drawing board, you will probably need to make several models anyway before you get it the way you want

>>1540189
its a parts kit and information on it is sparse, I can't bin the receiver sections and start over because it would be too damn expensive, but tack welding and brazing should be enuff

bump

i think as an added way to add some strength to the brazing I could drill a hole that doesnt go all the way through to pin the tubes in place together, and see if i can braze it in place

If you just need this one thing welded, why don't you just pay someone to weld it for you?

>>1540688
Didn't read the OP I see
>>just hire somebody to do it
>it's for a gun receiver, not illegal to do myself or with a friend, I just can't pay somebody to do it