Rivet Squeezing on a Budget
A test... inspired by some talk on the Gunco forum
I originally designed these in March 2004 because at the time I didn't have any money to put toward tons of shop tools, and I wanted to build an AK. Just one. The "right" way is to buy a 12-ton shop press, a special jig (or make your own), an air hammer, or chose any other "industrial" rivet solutions to assemble the AK properly, or screw the build together (but this isn't really the correct way to build an AK). What to do? Buy $200-$400 worth of tools just to build a $300 gun?
I realized that many many aspiring builders would love to build an AK but are intimidated by the complexity in comparison to something easier, like ARs for example, and set out to open the door for those people. This is the result of that pursuit. A low-tech, low-budget solution to rivet AKs that won't break the bank and will give you a "factory finish".
Picked up some 24" bolt cutters from a Harbor Freight sidewalk sale - $10 for the cutters.
They normally run around $15. Part #41149
I used two sets, not counting the one failure.
Here are some links to the REAL Hand Rivet Squeezers:
NOTE: I did this to my set of cutters, what you do to yours is up to you.
IF YOU DO THIS TO YOUR CUTTERS, it will void your warranty, blood-thirsty robots will roam the streets, your computer will crash, your bank account will be emptied, and God will kill a kitten. Think about the kittens.
I shaped the jaws with a 5" angle grinder.
I am trying to imitate the shape of pneumatic alligator rivet squeezers, or the hand-rivet squeezers which use the same yoke:
Needs some tweaking, but it got in there and began crushing the rivet...
Well I think it works. I have just riveted my front trunion rivets with this custom squeezer and I must say I am impressed. The rivet smashed almost like it was a foam earplug - barely felt it in the handles. I can't express how excited I am! For less than $20 and the cost of my shop tools, I have a rivet squeezer that WORKS. I have only tried the front two rivets, but it WORKS. At this rate, I could buy another set of jaws and shape them down for each set of rivets. Tested with the rivets from the recent group buy that 1-Pat put together... which BTW he's putting another one together on the Gunco group buy forum...
Note: This was tested on a BULGARIAN TRUNION... therefore I do not know how these measurements will work on other trunion types...
Note the angle of impact:
My test rivet - partially smashed. Really chewed up at this point, but I am just fitting it for now.
Squeezing the Rivets
That's 1/4" scrap metal with a concave head dremeled into it to allow the rivet head to seat. Works like a charm.
This rivet wasn't done too well, but I need only to test the clamping force at this time. My concern is that the rivet will not be seated deeply enough to allow the barrel to be reinserted... but not any more. I bit more minor tweaking of the jaw adjustment and it seated BELOW the edge of the notch, so YES there will be a small bit of clearance between the shank of the rivet and the barrel!
Finding that I need to do some final grinding. I have to get it fit properly to clear the trunion. I found that the bottom of the jaw creased the inside of the trunion, in the pic, this is directly below the rivet. So I need to round off the sides of the jaw so that it has a convex shape, and hopefully this will keep it from touching against the trunion:
Final grinding should be complete. Started with a new rivet, that other one is toast... yes, there is a scrap piece of sheet steel between the trunion and the head of the rivet - I wanted to get it as close to the real operation as possible... material was scrap from my Ace receiver blank.
And yes, that's a swell-neck rivet from the recent group buy that 1-Pat organized. ;) BTW he's currently working on another rivet group buy here
Of interest is the head of the rivet on top, nearest the piece of sheet metal - the bottom is my older rivet that is smashed...
On the flip side, the now-squeezed rivet shank in a nice clean little pancake:
Its hard to see, but I am trying to show the clearance between the barrel section and the rivet shank:
OK. Now let's see if I can set those rivets that are farther back on the trunion... yes they will fit!
Confirmed, the lower rivets are accessible by this clamp design, and even the rear trunion rivets look accessible... so the only unknown factors are the center trunion rivets - the jaw won't fit around the left of the trunion so I may try to grind it down further so as to fit this one.
If I can make it work, I may try to grind down the other jaw, so that I don't screw up the one jaw that works. I really need to find if another set of jaws can be purchased separately... if not I'll probably just get another set of cutters when I next visit Harbor Freight.
I was undecided on which way to approach the second rivets, so I took a guess and chose to go at it from the front, not the top. The left side of the trunion was my concern because it was so thick. It now appears that I will need to try from the top...
Started with comparison of the cuts on the first jaw...
Testing the fit of my first attempt...
I made the jaw itself thinner, so it would be able to handle that section of the trunion better... dremeled the thickness down to 1/4".
Ready to test...
OOPS! When it snapped, it sounded like a good-sided tree limb was broken.
OK. So this is how I am going to try this next time - from the top of the trunion, and I won't take out the extra material closer to the handles, because it seems I won't need to worry with the clearance this way. Anyhow, its good to know my limits.
Now off to HF for another set of cutters ;)
TESTING REDESIGNED CUTTER
Got the new cutters. Actually, got two sets...
Success! I didn't take this pic until after I was finished, so don't be confused by the left-side rivet:
The rivet squeezed with moderate effort. I was more careful here since there was more trunion material around this one.
Preparing to test for the left rear rivet:
That's it, all front trunion rivets are possible with my reshaped cutters!
In summary, all of the front trunion rivets are accessible by these modifications, and I spent a total of $20-30 for the cutters. I already had the shop tools and grinder. So in comparison to purchasing a set of true hand rivet squeezers which normally run around $130, I saved $100. And had a good time too. I don't see any glaring safety concerns with this approach, but YMMV.