preparehandbook 326 Posted March 4, 2012 Report Share Posted March 4, 2012 So, I was playing around with some riveting the other day (trigger guard) and it occured to me that forming the rivet might be made easier by heating the rivets red hot first, I figured when it cooled it would shrink up nice and tight. I know this was how big rivets used to be done (and might still). At first I worried it would unduly harden them, but as long as you cooled it slowly. I am going to drag some scrap metal and a torch home from work and try some hot ones versus cold ones and then destructively test them against each other, but this will take me a while to get around to as I am pretty backlogged on projects. Does anybody have any thoughts on the matter? Quote Link to post Share on other sites
gunfun 3,931 Posted March 4, 2012 Report Share Posted March 4, 2012 Some people use a micro torch or soldering iron to heat the rivets. I've smacked small rivets with a ball peen or a hammer and punch and they go easily enough in a few hits that I don't think heating is really necessary. I wouldn't want to risk detempering the receiver anyway. Further, you usually want to paint the parts before riveting them on, and heat could mess that up. I think you can put the rivets in and put a punch against them and spread them with 4-5 good solid whacks. The tricky part is going to be rigging a proper anvil around the trigger guard to back them. Quote Link to post Share on other sites
netpackrat 566 Posted March 4, 2012 Report Share Posted March 4, 2012 Heating the rivets is a bad idea. While they will appear to get tighter as they cool due to shrinkage in length, they will also shrink in diameter, which could lead to motion and ultimately a loosening rivet job. One of the advantages of cold driven rivets, is that they expand to fill the hole, and eliminate any motion that might have otherwise occurred such as with a bolted fastening. Also, if you are doing it right, the rivets drive just fine cold. I use an air hammer, but the hammer and punch technique described above works fine. Use a big enough hammer. 1 Quote Link to post Share on other sites
RED333 1,025 Posted March 4, 2012 Report Share Posted March 4, 2012 Heating the rivets is a bad idea. While they will appear to get tighter as they cool due to shrinkage in length, they will also shrink in diameter, which could lead to motion and ultimately a loosening rivet job. One of the advantages of cold driven rivets, is that they expand to fill the hole, and eliminate any motion that might have otherwise occurred such as with a bolted fastening. Also, if you are doing it right, the rivets drive just fine cold. I use an air hammer, but the hammer and punch technique described above works fine. Use a big enough hammer. +1 Quote Link to post Share on other sites
G O B 3,516 Posted March 4, 2012 Report Share Posted March 4, 2012 The old hot rivets that they used on ships and buildings were iron, they need to be hot to be malleable. The small rivets we use on AK's are mild steel and do not need to be heated. You do need a solid buck and a tool to set the rivet. The rivet can be set with a 32 oz hammer,an air hammer or a press. I highly recommend you practice riveting some scrap together before doing a firearm. You can make practice rivets out of 16p nails, they are the same steel as rivets. In a pinch they can be used to make those odd sizes of rivets that are hard to find, like the extra long one I needed for the wife's S-.410 UF. 2 Quote Link to post Share on other sites
ramlake 98 Posted March 4, 2012 Report Share Posted March 4, 2012 A solid surface and a small hand sledge hammer and they will form easily 2 Quote Link to post Share on other sites
preparehandbook 326 Posted March 4, 2012 Author Report Share Posted March 4, 2012 Maybe my OP was unclear. I'm not having difficulty with cold rivets (if I was I can't imagine a red hot one being easier to manage). I find cold rivets to be simple and easy and often do them freehand as I do a lot of rivet work in othe hobbies (by freehand I mean a hammer, punch, and buck vs a riveting doodad like AK builder sells or modded bolt cutters). My curiosity merely lies in the area of shrinkage, fit, annealing. I've got to look p the amount of shrinkage longitudinally and laterally to see if even on paper there would be enough longitudal "pinch" or too much lateral "slop" I was figuring on playing around with some flat stock and them stretching it through our 75 ton press at work and seeing which broke easier. Not very scientific and I'm sure some old codger who has done it before knows the fine points already, but I am a curious one. I'd have to see some pretty amazing results before I'd try it on a saiga, but I might play around with it on a cheap AMD65 (I have a refugee from a screw build) The responses to this thread have mirrored my own concerns for why this may be ineffective/fruitless. Quote Link to post Share on other sites
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