hey all.

i've got an idea floating around in my head.  got a yugo m70ab2 parts kit, gonna get a nodakspud reciever and have been floating ideas about how to join the two.  usually the most common ones i have heard about are the typical rivets, a screw build and u-drive method.  how about welding the trunions to the reciever?  i'm kinda new to building ak's and all, but thought that this would be a fairly straight forward process.

if not a whole welding job, how about just "tacking" the trunions to the reciever and then finishing off with a screw build?  seems easyer to drill/tap with the reciever already solidly in place...  thoughts?

-madtownrob

Welding can be used to hold guns together, HK did this for millions of G3 series rifles. The problem is this: rivets, screws, and welds all work to hold metal together. BUT, they work in different ways. The AK receiver and  trunnion were designed to be riveted together, not screwed or welded. We know that rivets hold AKs together for 100s of thousands on rounds of use, screws and rivets, not so much.

If resale is important to you, I'd never buy a screw or weld built rifle.

BSW

Personally I think is a bad idea.
Worse than a screw or U-drive build.
At least those can be rebuilt with rivets later.

With welding you  not only have to worry about the strength of the weld, but the strength of the heat affected zone.
The steel that the trunnion is made out of may not like the temperatures that is sees during welding.
It could become brittle and pose a risk of coming apart during firing.
Don't worry about the value of the gun.
Worry about your face and vision.

With the prices that Yugo kits are commanding these days and the price of Century built Yugos, you are better off selling the kit and buying one already built if you don't want to invest in doing a rivet build.

Of 3 1980's Yugo underfolders I've seen apart, one had been tack-welded once on each side in front of the short rivet that is alongside the barrel, right where other AKs have another short rivet.  I think those welds were just used for holding alignment while the first rivets were placed, because they were weak enough they broke when I peeled the receiver stub off.

Quoted: hey all. i've got an idea floating around in my head.  got a yugo m70ab2 parts kit, gonna get a nodakspud reciever and have been floating ideas about how to join the two.  usually the most common ones i have heard about are the typical rivets, a screw build and u-drive method.  how about welding the trunions to the reciever?  i'm kinda new to building ak's and all, but thought that this would be a fairly straight forward process. if not a whole welding job, how about just "tacking" the trunions to the reciever and then finishing off with a screw build?  seems easyer to drill/tap with the reciever already solidly in place...  thoughts? -madtownrob

I pretty much only do weld builds and have no issues at all with them. A "correctly" welded ak would have to shear off the receiver before the welds fail. But do ONE or the other, not both.

But I dont "tack" weld them. What I do is do rosette (plug) welds starting the puddle on the trunnions and then pulling the thinner receiver into the weld. You have to do this fairly smooth and quick so you are not cooking the living daylights out of everything.
Weld, clean, wait a little, repeat.
2-3 welds per trunnion including a few welds to the inside as well. Some people will run a bead at the top edge of the barrel block as well, I do not as I don't like the look or the cleanup needed.

But no matter what you do, do it RIGHT the first time.
Look for a new thread in a sec on how not to do a screw build.

Quoted: Personally I think is a bad idea. Worse than a screw or U-drive build. At least those can be rebuilt with rivets later. With welding you  not only have to worry about the strength of the weld, but the strength of the heat affected zone. The steel that the trunnion is made out of may not like the temperatures that is sees during welding. It could become brittle and pose a risk of coming apart during firing. Don't worry about the value of the gun. Worry about your face and vision. With the prices that Yugo kits are commanding these days and the price of Century built Yugos, you are better off selling the kit and buying one already built if you don't want to invest in doing a rivet build.

That is the best advice  and response that I have read in a long time ,Heed it..Pat

Quoted: Quoted: Personally I think is a bad idea. Worse than a screw or U-drive build. At least those can be rebuilt with rivets later. With welding you  not only have to worry about the strength of the weld, but the strength of the heat affected zone. The steel that the trunnion is made out of may not like the temperatures that is sees during welding. It could become brittle and pose a risk of coming apart during firing. Don't worry about the value of the gun. Worry about your face and vision. With the prices that Yugo kits are commanding these days and the price of Century built Yugos, you are better off selling the kit and buying one already built if you don't want to invest in doing a rivet build. That is the best advice  and response that I have read in a long time ,Heed it..Pat