Silver solder part deux

[main_cogg]

It's been years since I've used it, but they make silver solder paste, too. It's a mix of alloy and flux and is available with different melting points. It takes some trial and error to get the right amount so that it doesn't go everywhere. It also helps if you can purge the oven for the process.

 

[NC Rick]

I may have to re-design so it can be spot welded. the existing rails have rivets that go under the charge handle cover, so the rails must be attached first. They are in the way of doing a spot weld. Does not work to have a thick piece of 4140 (0.125"), then a 0.060" sheet (receiver), then another 0.060" (charge handle cover) and try to spot weld the last two.

For TIG, need no welding showing on the sides of the cover. So we drill holes in the cover and tried plug welding. Just cannot get a enough heat with 5/16 holes. Went to 3/8 and then it burns out the side at least once. I am using a pro - my son - he welded for a living for two years.

Anyway, if i can silver solder, it will save scrapping several parts and re-design. Also hi temp silver solder is out - would loose the temper on the 4140.

While 4130 is quite straightforward to weld, the 4140 is more tricky, I would want to check in to spot welding that stuff. 4130 is less difficult to find in sheets too. Interesting.