I have gathered all the makings for my AMD-65 pistol, and I was contemplating rivets versus screws, when I remembered some Hesse hack weld jobs. I started thinking how nice it would be to have a smooth sided (no rivets or bolt heads) pistol receiver. Would a spot weld be practical ? What kind of equiptment would be needed, as I figger that the sheet metal type attachments for an Arc welder would not work on the thicker trunnions. How about a plug weld ? What kind of rod should be used ? Would TIG be alot better ?        

Don't try Arc Welding...Ive seen some Super Talented folks who can do it well enough (Im not one) to smoothly plug weld a receiver without porosity or spattering.  I am NO Welder, so I can't give amp settings etc... but I have built 4 AK's and had others do the welding for me.  Wire welding will do ok if you keep the temp. just low enough to give you some good melting, blending of the trunion and receiver. Good thing about Wire Welding is that if you have predrilled your holes a slightly then the wire itself will act as the fastener as it fills the hole.  My personal favorite is TIG...  but grind and clean about an 1/4" around the trunion holes and then around the receiver holes.  Drill the rivet hole out in the trunion about 1/8", then plug weld it with the TIG.  It makes the nicest round "rivet-like" bumps on the receiver.  In fact on one I ground the peak off each bump and took a 1/4 Dremel Sandpaper Roll and ground it around on the outside edge of the bump until it left a crease around it looking just like a rivet.  One of the ones that I had wire welded has well over 3500 rounds shot thru it with NO problems or cracks.  The others except for the latest have had well over a 1000 each.  My 12 year old son can BURN UP some 7.62X39 Ammo!  I am expecting Wolf to give him an all expense paid vacation or something.... :-)
OH well. hope that helped a little, maybe I can find out from my buddy exactly what settings / materials etc. he uses on the Tig and the wire weld.  If so I'll write you back.
see ya
T2

TIG would definitely be the way to go.  This welding process provides the cleanest and most professional looking results, if you have the right equipment.  You will need at least a DC power source with leads, TIG torch assembly with 1/16" or 3/32" electrodes, and Argon as a shielding gas.  The filler rod should be compatible with ferrous metals, and these are readily available from any welding supply company such as Holox or Pye-Barker.  A high frequency set up and remote amperage control such as a foot pedal or thumb switch is also recommended, but not really necessary.  These items would give you more pinpoint control over your arc/bead as opposed to "scratch start".  I would stay away from MIG or SMAW...  

For home welders and people getting it welded by a friend, a MIG is the best option (TIG is $$$$).  You'll be grinding down your weld anyway, so why not use MIG??  Welding isn't hard with a little practice, no need for a TIG with foot controls and whatnot.  Think anyone can tell a difference between my MIG welds and someone elses TIG welds when they're sanded down?  Get/use a gas MIG and pull the trigger (after practicing and learning the machine).  It ain't that hard or complicated.

FRIENDS DON'T LET FRIENDS MIG WELD AK'S TOGETHER!

Please...  Your friends must be bad welders...  

lets hear more of this welding

cmon campy is it safe to weld together a bitch gun?

First of all, I prefer rivets, and do not care to do any welding on my receiver.  However, there is "more than one way to skin a cat", and if folks prefer to use screws or welds as an alternative means of assembly then so be it.  Apparently these other methods do work, hence the interest in utilizing them.  The question about welding posed by bulletslap really didn't address cost issues but rather which welding process would be the better choice.  As a welder myself in an industrial environment, I feel that I can offer my opinions from a more technical aspect rather than which one is cheaper.  First of all, there is nothing wrong with MIG welding as it relates to this particular project.  With the proper constant current/constant voltage setup, the proper slope adjustment in relation to the wire diameter will enhance the quality of a MIG weld.  My reasons for preferring TIG has to do with the DC straight polarity setup, which allows for more penetration due to the increased allocation of heat at the positive pole, as compared to MIG welding.  If the welds are to be ground smooth, you'll have a much better weld joint with a TIG weld, as most of your weld will be intact instead of being ground off.  You are right; I doubt that anyone can tell the difference between the MIG and TIG weld after grinding smooth...it's what's beneath the surface that counts.  Something else to consider...some receivers may be hardened in which case you may want to avoid welding altogether.  Steel that has more than .30% carbon can harden excessively around the weld area, causing brittleness and subsequent cracking.  Additional annealing procedures would have to be utilized in addition if hardened receivers are welded.  

Totally agreed mp5, we just went after the question two different ways, you from an industrial background and me from a frugal home do-it-yourselfer background .  I agree with every point.  I also don't plan on welding together anymore AKs, even though my MIGed AMD is really strong and holding great.  Good point with cracking around the weld too, I think a lot of people don't take this sort of thing into account (me included sometimes).  Sorry if I came off as an ass...

Interesting thread on welded AK's.

Welding AKs

Squeky: No need to apologize...that's why we have discussion forums, to talk about these issues and share ideas so that we all can safely build and shoot AK's.  Whether it's in an industrial or a home environment, familiarization and training in either welding process is essential for proper results.  

Maxxx93: Wow! This definitely reinforces my above statement about knowing what you are doing.  From looking at the photos, it looks like the amperage was set too low, allowing the wire to fill up the holes without penetrating the trunion, a common mistake when plug welding with a MIG.  By increasing the amperage setting in relation to the voltage (wire speed), a proper plug weld can be achieved with a MIG.  I still prefer TIG simply because you are able to initate better penetration to ensure proper bonding of the trunion and the receiver.  

that was a horrible job there

Quoted: that was a horrible job there

Absolutely,
The scary part is that, it was not a home build, he bought it that way.