Help!! I Can't Rivet Worth a Crap.

[DougF]

So far, building this M53 has been fairly pleasant but yesterday and today, I've been REALLY frustrated. Lot's of builders have griped about welding or some other aspect of the build but I don't remember anyone saying much about how hard riveting was for them so I must be doing something wrong.

The biggest problem that I'm having is that I can't get the rivets to form a dome that is tight against the surface. Yeah, I know that I'm leaving those half moon marks but after I noticed that I was leaving them, I ground a little off of the face of the driver and that fixed that problem for the most part.

These pictures are of the tops, bottoms, and a couple of side views. Unfortunately, I wasn't careful about ensuring that the factory heads were all on the same side of the metal strip so some of them don't look too bad but that is misleading. There was only one that I would have accepted (but not pleased with) and I circled it in red.

I've taken a picture of my pneumatic hammer which I ran at 90 and 110 psi. Also included are some closeups of the driver that I ground myself. Finally, I included some closeups of the rivets that I attempted to set. For a couple of them, I used a torch to get them red hot but it really didn't seem to make a whole lot of difference. Yesterday, I started off driving the rivets with as much down force as I could apply. They were really mangled. Today, I was a little more gentle at first and they came out a little better but I could never get a domed head to completely form even when I was putting all my weight on the hammer for almost a minute. The hammer requires 3 CFM at 90 PSI. My compressor puts out 6.4 CFM at 90 PSI.

Can someone coach me on how to get a tight domed rivet head? Thanks in advance.

[Michael J]

I use a ball peen hammer and do them by hand . Mind you, i have avoided rivets altogether so far on this particular build by welding everything, and building up welds as to appear as rivets .

[Bil]

For starters,you need to back up your rivets.That means that the preformed head must be tight against the material,and must stay there.You should have a rivet buck inside the rails,or for practice like you are doing,a piece of steel with a relief that the rivet head will just fit in,and clamped tight.No bounce,you are spreading the force all over without it.There is a picture in the thread'Bil's build,with dimentions.Also,Pirate used to sell them,check with him.I think your rivet tool needs to be milled a little deeper-you want it to be the final shape of the rivet,but not quite as deep,so you don't gouge the receiver.I also used a hammer,bucking block in the receiver,and the receiver blocked on a steel table to absorb any bounce,and to keep from bending the receiver.Remember that if you are applying force to the side of the receiver,it will bend. I also heated the rivet shaft,and the rivets I send out are longer than nessesary,cut to fit your rivet tool.Hope this helps.BTW,the correct rivet length is in one of JBaums book,a list of all rivets in the gun.I am far away from my copy,so no help with the length. ---bil

[DougF]

Thanks MichaelJ and Bil.

I held the strip on the anvil of my vise and of course, the pneumatic hammer's force was being divided between both sides of the rivet!!! That makes perfect sense. That's why the factory dome was getting flattened rather than the shaft.

According to a post I read somewhere on this forum, the length of the rivet shaft is supposed to be - the thickness of the material + 1.5 * the diameter of the shaft. I ground my rivets down to that length + or - a few thousandths.

Okay. Tomorrow, I'm going to make up a backing plate with a nice dimple and I'll deepen the dimple in my driver and give it another try.

I can't thank y'all enough. Whew. I feel better already.

[DARIVS ARCHITECTVS]

Doug: Wrong tools, bad technique. Believe me. I'm a medieval armourer with over 20 years experience riveting by hand. If you want to do it right and stop the frustration, listen to me. This job is doable with the right tools and some practice.

Bil's advice is sound. Here's a neat tool tip: If you don't have a proper rivet set set upside down in a vise to act as a backing, us a block of lead. You may have to move to a flat portion of the lead surface about 3-4 times before the shank of the rivet is finished on the opposite (hammer side). Also, you can FLUSH RIVET the back side of the strip. Take the strip with the holes in it, and bevel each of the holes with a larger drill bit (on the unseen inside side). cut or file the rivets such that the shanks are a TINY bit longer than the thickness of the strip. Backing the dome rivet up with something that will not flatten or deform it, like a rivet set tool which is upside down or a block of lead, mushroom over the shank with a ball peen with MANY MANY MANY MANY light taps, NOT a few HEAVY ones. You want to move the metal SLOWLY. The metal will tend to fille the beveled volume, forming a lip that is flush with the back of the strip. If you hurry, youll mess it up. Orbit the shank edge, peening it over. Make the shank edge curl EVENLY all the way around 360 degrees and you go. If you smash one side over more that the rest, you will BEND the SHANK and DEFORM the nice rivet dome! It's ALL TECHNIQUE and patience. I have trained MANY apprentices in the Art or Armouring over the years. Fail to listen and your will piss yourself off bigtime, because AT THIS STAGE in the game, you are an apprentice with a hammer and things go 5 times slower than with an experience metal smith. SO TAKE YOUR TIME. Remember, you don't need a LOT of peened over shank to hold the rivets in. The last blows you make should be FLAT ON, to SWELL the shank, and SET THE RIVET HARD into it's final place.

If you work at it for at least four years, you can make stuff like this:

[42rocker]

Wish that I was as good setting a rivet as DA. Nice work... But another way that I read about and thinking about trying is to start with hammer or air gun and do the first 2/3's or so then set the last bit using a press. However do what you are doing PRACTICE like you are doing and find what works best for you.. Several on 1919 heat, many don't, some use just a press start to finish. I know that on the last several ak's that I worked on there were times that I thought that I knew what I was doing, then the very next rivet would go badly....
Well keep on trying and Good Luck... Glad to hear that your welding goes well..

GOOD LUCK

Later 42rocker

[Bil]

I don't know how the rivets are on the 1919,but on the 42/52,the inside is hard to get at,you will need a bucking tool,easily made.Keep at it and you can get as good as DA,look at the finely made armour,I think he even made the German outfit from riveted pieces! You should see the mail shirts he does,a real craftsman.[now I have undone all the bad things I said! ] ---bil

[DARIVS ARCHITECTVS]

Yep.. Gotta start over now, Bil. You want me to say afew stupid things to help you kick things off and give you something to work with ? <--- here's your shot, Bil

[DougF]

I want to thank everyone for their input. I made a lot of progress and am pretty much satisfied that I can make some goodlooking and solid rivets on my machinegun.

The first set of pictures are of the rivets that I set using only the pneumatic hammer. The left two were heated and the right two were driven cold. They look much better than what I had done yesterday.

This set of pictures shows the rivets after I used a hammer to shape them. Actually, I used a hammer and punch to shape them and then cleaned up the finish with the pneumatic hammer. The hot rivets were too hard to shape so I think I'll set them cold on my gun. DA, I thought you were crazy and told my wife that I wasn't going to individually hammer the rivets on these guns but it really works and the right one looks pretty damn good after only 10 minutes of work. Thanks.

I still need more practice but I'm getting there. Thanks again, everybody, for the help.

Can anyone recommend a good place to buy a couple hundred of these rivets for a cheap price?

[DARIVS ARCHITECTVS]

Too long on the rivet shank Doug! You are trying to push way too much metal. DO YOU SEE A GAP BETWEEN EACH RIVET HEAD AND THE STRIP? You shouldn't. By moving so much of the shank, you are SWELLING the shank outward prematurely, making the dome on the other side freeze in position with a gap between it and the strip's surface. Grind the rivet shanks down to just 1/32" above the surface of the strip. Don't make work for yourself. My Master used to say when I was just an Apprentice, "Work the metal, don't let the metal work you". A little grinding will go a LONG way to save pounding!

Don't give up yet. You're HALFWAY there.

Another tip. Take a GOOD CLOSE LOOK at one of your rivets. See where the shank and the bottom of the dome meet? The corner isn't sharp, is it? If it were, a stress crack would form and the rivet heads would just POP OFF under stress. There is a VERY SMALL radius there. Well, on the strip, you have to make room for that metal! Take a large drill bit in your hand and take the corner edge off each hole BEFORE you insert the rivet. Twist that burr off of there! See how the head lays flush with the strip when inserted now? No gap!

It's all in the prep work, buddy!

[DougF]

Thanks for the tips DA. I didn't even think about chamfering the edge of the hole. Great idea and it makes sense.

1/32"!?!? Will there be enough metal left to form a dome? I'm practicing to rivet the rails on my M53 and I thought they were supposed to be domed.

[Bil]

Ah-Grasshopper-you can learn much from the master! He can teach much.As for me,the lowly rivet supplier,I woild suggest if you need that many rivets,you go to my secret rivet supplier,Grainger,or MvMaster-Carr.5/32X3/4 at Grainger is $10.05 plus shipping for a bag of 185,or same price for 225 of 1/2 length.If you just want a set for one gun,I will send you some-I am getting a bag on Wednesday and sending bunches out.I am not at home,so had to get them locally.The counter guy looked at my account-I have never bought from the same Grainger store more than once!

[DARIVS ARCHITECTVS]

Thanks for the tips DA. I didn't even think about chamfering the edge of the hole. Great idea and it makes sense.

1/32"!?!? Will there be enough metal left to form a dome? I'm practicing to rivet the rails on my M53 and I thought they were supposed to be domed.

1/32" is only enough to HOLD the rivet in place, not creat a nice hemispherical dome. You need 1/8" of shank for that.

RIVETS STEPS

1) If you make hammer blow around the very edge of the shank in a circular orbit, you will only curl the edge.

2) After a first set of passes, making blow around the perifery of the shank, move your hammer to a smaller orbit, striking a tighter circle closer to the center of the rivet shank but not on the center - YET. Do a few more orbits of about 12 blows each, moving the metal a tiny bit with each blow.

3) After two passes on the shank edge (for curling) and the tighter orbit path (for pushing the shank downward, do 2-3 blows on the CENTER of the shank, to squash the pointy peak which has been forming there. That way, the shank starts to form a DOME and not a POINTY shape.

4) Repeat, starting at step 1).

Why do this pattern? It moves the metal of the shank throughout the entire volume of the shank without stretching any place IN THE metal to the point where it starts cracking. Hammer the edge too much and forget to make blows near and then on the center, and the edges of the mushroom your are forming WILL SPLIT AND CRACK. You won't get a pretty dome then. It will hold, but now it's ugly.

YOU CAN make the hammered shank as ROUND and PRETTY and the preform head of a rivet! It may not be as tall a dome, but it WILL be round and crack-free... WITH PRACTICE AND SLOW FORMING WITH LOTS OF LIGHT BLOWS!

Hammer Technique 101:
Focus your sight ON THE PLACE where the hammer strikes, so you can SEE the metal deform with each blow. This tells your where you are hitting, which GUIDES YOUR HAND for the next blow. NEVER LOOK AT THE HAMMER. It's like NOT looking at your hood ornament, but looking 1/2 mile down the road. Your path is smoother and straighter! You hammer blows are ACCURATE, and the next blow goes where you EYE tells it to go.

Class dismissed.

[Michael J]

Excellent tutorial DA! Hmm, why don't you copy and paste it into a new thread and make a sticky ?

I've always had the occasional rivet crack/split, and could never figure out how to avoid it. I just ended up doing the correct procedure by fluke for the most part. Now that i understand it better, i hope to increase my efficiency!

[Bil]

I tried that with the new guy at work-I said 'I'll hold the nail,and when I nod my head,you hit it". OUCH ---bil

[DougF]

Thanks Bil for the offer of some rivets but I'll just buy a bag so I can waste a few if I need to.

DA, thanks for the coaching. I've got a few rivets left to practice with today and I'll save four so I can at least install my rails and finish the other stuff that depends on them. Then I'll go back and put the last eight in once the shipment gets here. I'm anxious to get out in the garage and try these new techniques.

Thanks again everybody. I'll post pics when I get my guns completed. I noticed yesterday that IMA sent me two receivers that were separated by one serial number. Dang.