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If you are struggling with riveting in general or with riveting cut/sheared rivets then what I share below has really worked well for me as an A&P. I riveted decently out of A&P school but an old IA taught me what is below.
People have trouble driving rivets they have cut with a rivet cutter tool that's made for shearing off the rivet to the desired length. This can be due to the fact the sheared end isn't perfectly flat so it throws the bucking bar at a bit of an angle. I've used a rivet cutter like that for thousands of rivets without issue. If you are having a problem with sheared rivets using a rivet cutting tool (not a pair of wire cutter/dikes but an aviation tool made for shearing rivets) I'm guessing it's one of three things: a gun with poor speed control, a finger with poor speed control, or too much air pressure. I watched a video of a bearhawker who made a jig, cuts the rivet with a pair of dikes, then sand it down with a die grinder. I shook my head thinking that's way too much work for cutting a rivet,. Apparently many bearhawkers end up avoiding a rivet cutting tool and doing something crazy. Let me help you use that rivet cutting tool and save you a lot of time and effort. Seriously, it's pretty easy and will make sense if you follow along.
Besides the usual "Keep the gun perpendicular and lightly but firmly pushed into your work and the bucking bar flat to the work (sure, everyone knows that)" here's the key with a cut rivet from a rivet cutting tool. Start very slowly on the first 3-4 hits so the not-as-perfectly-flat sheared end of the rivet gets flattened in those 3-4 hits. Once it's perfectly flat from the 3-4 hits I speed the gun up until I have the flattened height I desire then stop and inspect. I can see having problems with cut rivets if you just pull the trigger full on and let-r rip because any angle on the cut will throw the bucking bar off at an angle and once the bucking bar is out of kilter then get the drill. Use the 3-4 slow hits to flatten the end then you can speed up to finish. Dit dit dit dit brrrrrrrr constantly speeding up until done.
For a demonstration, look at https://youtu.be/37SQj_WMnPA?t=946 and that's the speed (where he hits the table) that I use for the first 3-4 hits. He also demonstrates good speed control constantly speeding up at 17:00 minutes in https://youtu.be/37SQj_WMnPA?t=1020 I do a combination of both those parts of the video by putting them together: I give 3-4 really slow hits to get the sheared end flat, then speed up consistently until done. He does similar in this clip but I don't give it quite as many slow hits but you get the idea https://youtu.be/37SQj_WMnPA?t=1300 I'm not sure who that guy is and I didn't watch his entire video but he has good technique with the gun. Give that a try and I think you'll be pleasantly surprised with all your rivets. Doing it this way in the slow stage you can stop if things are going awry after a few slow hits (I think that's why the guy in the video is going slowly because he's watching that his angle is correct with the bucking bar) and correct it before ruining the rivet. If you just pull the trigger full on you have a greater chance of not catching a misalignment early on then you have to redo it.
Perhaps your rivet gun doesn't have good slow speed (some are very bad) or you might have the air pressure too high so the gun always runs fast and hard. I have used guns that don't have good speed control and for that I can see problems but the problem lies in the gun or the trigger finger, not the sheared/cut rivet. I have an Ingersol-Rand gun that was bought from Boeing surplus that has great speed control and is the nicest running gun I've ever used. Don't be afraid of a good quality surplus sale gun. The aircraft factories don't tend to buy junk guns and they are hard to wear out. When I was in A&P school you learned which guns you could really control the slow speed and which ones didn't and if they didn't I didn't use them. It was funny too when guys ran too much air pressure and would always have problems over-driving rivets, bending the piece (especially with flush rivets) or not being able to control the gun and bar well making smileys on the rivet head or worse yet on the piece. If they just lowered the air pressure a bit they could eliminate many headaches. Some folks think of the trigger on their rivet gun like a trigger on a firearm which is like an on/off switch and not like a rheostat/fully adjustable switch. Think a variable speed drill trigger and not on/off. If your air pressure is too low it won't hit hard enough and you'll work harden your rivet and have a hard time getting it to half the dia height.
I think if you try this technique you will find a rivet cutter is a handy tool. If you use this technique on all rivets you will find you can be really consistent because you have good speed control and things don't get away from you because you are going slow enough you can stop before ruining the rivet. You will have to drill out a lot less rivets, saving you much time and aggravation. In my experience a slower gun makes faster work and a faster gun makes slow work because you end up drilling out rivets and redoing them or worse yet replacing aluminum pieces.
One last tip many know but some don't, put a small piece of masking tape on the end of the rivet set in the gun (where the dimple is for an470 rivets or the contoured end for flush rivets) as it cushions the rivet head slightly which leaves the head looking nice when done.
I hope these are beneficial for someone who is having problems with riveting in general but especially with cut rivets from a rivet cutting tool.
Jay
People have trouble driving rivets they have cut with a rivet cutter tool that's made for shearing off the rivet to the desired length. This can be due to the fact the sheared end isn't perfectly flat so it throws the bucking bar at a bit of an angle. I've used a rivet cutter like that for thousands of rivets without issue. If you are having a problem with sheared rivets using a rivet cutting tool (not a pair of wire cutter/dikes but an aviation tool made for shearing rivets) I'm guessing it's one of three things: a gun with poor speed control, a finger with poor speed control, or too much air pressure. I watched a video of a bearhawker who made a jig, cuts the rivet with a pair of dikes, then sand it down with a die grinder. I shook my head thinking that's way too much work for cutting a rivet,. Apparently many bearhawkers end up avoiding a rivet cutting tool and doing something crazy. Let me help you use that rivet cutting tool and save you a lot of time and effort. Seriously, it's pretty easy and will make sense if you follow along.
Besides the usual "Keep the gun perpendicular and lightly but firmly pushed into your work and the bucking bar flat to the work (sure, everyone knows that)" here's the key with a cut rivet from a rivet cutting tool. Start very slowly on the first 3-4 hits so the not-as-perfectly-flat sheared end of the rivet gets flattened in those 3-4 hits. Once it's perfectly flat from the 3-4 hits I speed the gun up until I have the flattened height I desire then stop and inspect. I can see having problems with cut rivets if you just pull the trigger full on and let-r rip because any angle on the cut will throw the bucking bar off at an angle and once the bucking bar is out of kilter then get the drill. Use the 3-4 slow hits to flatten the end then you can speed up to finish. Dit dit dit dit brrrrrrrr constantly speeding up until done.
For a demonstration, look at https://youtu.be/37SQj_WMnPA?t=946 and that's the speed (where he hits the table) that I use for the first 3-4 hits. He also demonstrates good speed control constantly speeding up at 17:00 minutes in https://youtu.be/37SQj_WMnPA?t=1020 I do a combination of both those parts of the video by putting them together: I give 3-4 really slow hits to get the sheared end flat, then speed up consistently until done. He does similar in this clip but I don't give it quite as many slow hits but you get the idea https://youtu.be/37SQj_WMnPA?t=1300 I'm not sure who that guy is and I didn't watch his entire video but he has good technique with the gun. Give that a try and I think you'll be pleasantly surprised with all your rivets. Doing it this way in the slow stage you can stop if things are going awry after a few slow hits (I think that's why the guy in the video is going slowly because he's watching that his angle is correct with the bucking bar) and correct it before ruining the rivet. If you just pull the trigger full on you have a greater chance of not catching a misalignment early on then you have to redo it.
Perhaps your rivet gun doesn't have good slow speed (some are very bad) or you might have the air pressure too high so the gun always runs fast and hard. I have used guns that don't have good speed control and for that I can see problems but the problem lies in the gun or the trigger finger, not the sheared/cut rivet. I have an Ingersol-Rand gun that was bought from Boeing surplus that has great speed control and is the nicest running gun I've ever used. Don't be afraid of a good quality surplus sale gun. The aircraft factories don't tend to buy junk guns and they are hard to wear out. When I was in A&P school you learned which guns you could really control the slow speed and which ones didn't and if they didn't I didn't use them. It was funny too when guys ran too much air pressure and would always have problems over-driving rivets, bending the piece (especially with flush rivets) or not being able to control the gun and bar well making smileys on the rivet head or worse yet on the piece. If they just lowered the air pressure a bit they could eliminate many headaches. Some folks think of the trigger on their rivet gun like a trigger on a firearm which is like an on/off switch and not like a rheostat/fully adjustable switch. Think a variable speed drill trigger and not on/off. If your air pressure is too low it won't hit hard enough and you'll work harden your rivet and have a hard time getting it to half the dia height.
I think if you try this technique you will find a rivet cutter is a handy tool. If you use this technique on all rivets you will find you can be really consistent because you have good speed control and things don't get away from you because you are going slow enough you can stop before ruining the rivet. You will have to drill out a lot less rivets, saving you much time and aggravation. In my experience a slower gun makes faster work and a faster gun makes slow work because you end up drilling out rivets and redoing them or worse yet replacing aluminum pieces.
One last tip many know but some don't, put a small piece of masking tape on the end of the rivet set in the gun (where the dimple is for an470 rivets or the contoured end for flush rivets) as it cushions the rivet head slightly which leaves the head looking nice when done.
I hope these are beneficial for someone who is having problems with riveting in general but especially with cut rivets from a rivet cutting tool.
Jay
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