What kind of steel? Best welding material?

[prexigrass 0]

I have a friend who owes me some time at his machine shop. I trade computer work for machine shop labor. I was going to have them weld the back plat onto my saiga 12 for my ace folding stock. And maybe even weld over and smooth out any leftover holes in the receiver from doing the conversion. What I need to know is the following. I already spent about 15 minutes looking for these answers to no avail. So I thought I would ask here.

 

What type of steel is the receiver?

 

What do you guys use, or what would be best for welding tools/material to weld it with?

[Wotan1105 7]

I'm no expert but my brother welds and waiting for the chance to do about the same as you. Can ask him later if you don't get a good answer here. Fill holes, weld back plate on, etc.. It's not rocket science, tig welder, probably stainless welding rods, done and done brush and finish. There isn't a whole lot to it. This has to be a terribly simple job for a welder. Only question I really had is it worth welding the entire back plate on as opposed to spot welding it on in a few corners and finishing? Would assume weld the whole thing and finish would be how the pros would do it, for appearance and workmanship. Never inspected a professionally converted gun to check the back plate.

Edited March 12, 2009 by Wotan1105

[Starballs_135 1]

don't know what the reciever is but any mild steel would work for the rear plate ur speaking of, pic a good thickness, and try to manage heat as recievers are heat treated and u would be anealling i.e. re softening, if that word works for u, anything that heats to much, ur little back plate will not be standing up to what the rest of the reciever does

[Gunfixr 76]

I TIG weld them on, and fill the rivet holes the same way. I use a basic general mild steel weld filler rod for this, and have had no problems. You could also use 309SS filler rod, a stainless filler, with just as good results. 309 series is better for dissimilar metals, or unknown metals. Since the receiver is hardenable, be careful about cooling the welds. Water quenching isn't recommended, as you could create hard spots, which might crack later, especially at a stress point, such as on a back plate.

The back plates are made almost the exact size of the outside of the receiver. When the plate is placed on the end of the receiver prior to welding, this leaves a seam to seal up all the way around, except for across the top, which is a corner fillet. The receiver is thin enough that cutting a "v" around the edge to fill in isn't very practical. Adding the "v" would strengthen the weld greatly. So, since this cannot be done easily, a little more heat is used, and moved over the surface a little more slowly, so that the fusion penetrates more thoroughly. Filler is still needed, or the fusion point will be too thin. Since the weld is not likely to be perfect all the way around, it should be welded all the way around to ensure there's enough good weld to hold it securely.

After all, when the weld is dressed down smooth, most of it will be gone, except where you get it to fully penetrate. Too much heat will melt off the corner, and it'll look like shit.

 

You want it to look like it was made there to begin with.

[Project_Pat 0]

I TIG welded mine with ER70S2 1/16" dia. welding rod............as the member above said just general purpose steel welding rod.

 

Make sure you get good penetration when you weld in the back plate....or the weld may crack.

[skiboatsp 111]

I use 1313 filler, a 1/8" plate that is beveled .060 or so for good penetration

 

Low heat, careful to keep edge crisp.

 

Finish by dressing corners with file

 

 

[Azrial 1,091]

Nice work!

 

The 4 hole on the end is pretty interesting, what was the purpose of the lower set of holes?