What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Rivet removal: expert advice requested

SabreFlyr

Well Known Member
Sponsor
Preparing to preform SB 16-03-28 on my pre-SB QB RV-14 wings as I begin this phase of construction. The SB requires drilling out 16 AN470AD4-5 rivets attaching the inboard aileron hinge brackets to the rear spar. I’ve put 24 similar rivets in a couple pieces of scrap totaling nearly the same thickness. As you can see from the attached pic, I can’t put my rivet removal tool on the rivet heads in proper perpendicular position. Therefore, I’m not using the tool for my practice. However, since the rivets on the wings still have nice dimples in their heads, I did use the tool to make centered dimples in the practice rivets. I’ve decided that I’m not going to attempt removing those 16 rivets on the wings until I can remove 24 practice rivets in a row without any elongated holes.

In the first four rivets I’ve removed, the holes I’ve drilled in the heads have all gone off center after starting centered. I’m having to use a 5-1/4” drill bit because that is what I’ll need to clear the hinge bracket. I might be putting a bit of pressure on the drill and causing the bit to flex a little and wander off center. But, suspecting that, I was very careful on the fourth practice rivet not to use anything but the slightest pressure and still ended up with an off-center hole for removing the head. That also starts me off center drilling with the #40 bit to drill out the shank.

I’d like to hear what some of you do to keep your holes centered when drilling out universal rivets.

All this being said, I DID use my rivet removal tool at about a 3-4° “angle of attack” on the fifth practice rivet. It was actually the best of all five and my starting point for drilling out the shank was the most centered of all five. Leads me to believe that maybe I SHOULD use the tool for drilling the heads of the “real” rivets.

Also, all five drilled out holes were at least what I would consider minimally satisfactory, the worst of them being only very slightly enlongated. I just wouldn’t want more than 2-3 per side like that.
 

Attachments

  • 2173B707-946B-4A89-9F41-723AE4C9FB69.jpeg
    2173B707-946B-4A89-9F41-723AE4C9FB69.jpeg
    556.6 KB · Views: 257
I like to get the hole started with rivet removal tool as you show - just deep enough so that a bare bit won't slip off the rivet head. THEN I use a long #40 bit to center the hole and drill it a bit deeper than the rivet head - this centers the hole much easier than using a #30 bit. THEN use a long #30 bit to drill the head just deep enough to pop it off - then pop it off. Now you can see the original hole easily. THEN drill center just a bit deeper with a #40 bit (just deep enough to avoid drilling all the way through). Then support the material just next to the back side of the rivet (shop head) with a bucking bar while driving the rivet out with a #40 punch (or a tapered punch)

Lots of steps, but much more consistent center drill results and holes rarely enlarged...
 
Last edited:
I had a similar problem. I used an auto-spring center punch about 6 or 8 times to punch a deep mark in the center of the manufactured head. Then, I used a 24" long #30 drill bit to carefully and slowly drill the head off. The, I used an awl and a mallet to punch the shank and shop head out the other side.

I had to go slow and bend the bit around a little to keep it directly centered. I'd drill a little, lift the bit to check, then drill a little more. But, it worked. And, I did not elongate the original hole.
 
Drilling rivets

I had a similar problem. I used an auto-spring center punch about 6 or 8 times to punch a deep mark in the center of the manufactured head. Then, I used a 24" long #30 drill bit to carefully and slowly drill the head off. The, I used an awl and a mallet to punch the shank and shop head out the other side.

I had to go slow and bend the bit around a little to keep it directly centered. I'd drill a little, lift the bit to check, then drill a little more. But, it worked. And, I did not elongate the original hole.

That's what I would recommend. #40 bit should have plenty of clearance but you still want to be as close to center as possible. I also recommend a second set of hands so someone can hold a bar behind the part.
Make a set of these. Very handy
https://drive.google.com/open?id=0B7hyZ-sKQmtremd0cEtqaW1NMWc
I use a pin punch modifed to be used in a rivet gun because I work alone. I don't recommend it because it packs a whallop but in the right hands, it's really useful.
 
Down the center with a #40

I use a #40 and even #50 drill and go down the center. Then when I go just deep enough I look down the hole and if I’m down the center then open up the hole with the next size up.. I also try to not go below the parts surface and use the butt of the #30 drill ( in this case ) and wobble the drill and the head breaks away. The shank and buck tail still have their stress to be relieved, and a smaller drill going down the center of what’s left a small amount going below the surface of the work to relieve the internal pressure will allow the shank and buck tail to get pulled or pushed out, think. The 12inch drill is your friend.
This works for me and in no way is a recommendation and any loss or damage resulting from ones own work is not my responsibility.
 
Last edited:
Then, I used a 24" long #30 drill bit to carefully and slowly drill the head off....

I had to go slow and bend the bit around a little to keep it directly centered.

Ken, are you using the long bit so that you CAN bend it around and guide the bit more as you drill? Otherwise, why such a long bit?

That's what I would recommend. #40 bit should have plenty of clearance but you still want to be as close to center as possible.

Larry, you're saying that your doing the same thing but with a smaller bit, right? I had imagined that I should be using as short a bit as possible.

Also, since I have access to the shop heads on the forward side of the spar, I'm also guessing that I will be able to use flush cutters to twist the shop heads out.
 
Drilling rivets

Ken, are you using the long bit so that you CAN bend it around and guide the bit more as you drill? Otherwise, why such a long bit?



Larry, you're saying that your doing the same thing but with a smaller bit, right? I had imagined that I should be using as short a bit as possible.

Also, since I have access to the shop heads on the forward side of the spar, I'm also guessing that I will be able to use flush cutters to twist the shop heads out.

Yes. I almost always drill 10 smaller. Then I use a drill stop with the correct drill bit to only drill the depth of the head. Snap it off. I sometimes try to twist out from the shop side but it is not always successful. The bar and punch always work.
 
One of the points of my earlier post is that a long (I use 12") #40 bit is easy to bend in such a way as to keep it centered on the rivet - as Billytime1 says, drilling out the center of the rivet makes it easy to punch out the rest.

Once the center is drilled #40 (but not all the way through the rivet), get the head off using a "just deep enough" use of the #30 bit. After this, and removing some of the center of the rivet with #40 bit, easy to punch out.
 
Sorry but I guess i drilled out too meny rivets in my time. I would use rather a long drill and bend it, or use a 90* drill motor. Just drill the head then use a punch and hammer to remove the shank. Backup the meterial when doing so, and if it refuses to pop out exalt, drill a little deeper, and try punching it out agin. You know you’ve gone through the center when as your drilling you pop through suddenly and it surprises you. I mean to say the tail pops out. Anouther method is to lightly tap the back of your drill motor with your palm as you drill. The bit will pop the tail out. Also every time you drill out a rivet the hole it inlarges/elongates. Drilled holes aren’t round thay look like a figure 8. And when you shoot the rivet thay expand into the hole however shaped it is. That’s why thay sometimes disappear into the hole.
Hope this helps. Good luck.

RD
 
Ken, are you using the long bit so that you CAN bend it around and guide the bit more as you drill? Otherwise, why such a long bit?



Larry, you're saying that your doing the same thing but with a smaller bit, right? I had imagined that I should be using as short a bit as possible.

Also, since I have access to the shop heads on the forward side of the spar, I'm also guessing that I will be able to use flush cutters to twist the shop heads out.

I use the long bit so that i can bend it. The jobber length bits chucked up in my favorite HS drill motor just won't get perfectly perpendicular to the head. So, the extra long bits are flexible enough to do this. If I have a bit that's 2 or 3 numbers smaller, I'll use it. But, i've found if I'm careful, the #30 bit will do the job without enlarging the hole noticeably.
 
Also the long bit allows you to get closer to a rivet that is right up against some.min this case you can’t get the rivet removal tool straight up and down because of clearance, the same would likely be true of a drill chuck with a short bit.

I have screwed up so many rivets and had to drill them out that I can start well off center and chase it back to center, almost in my sleep. You just need to drill out a few hundred of them. :p

But for sure a long bit is the way to go. When I don’t need to use a long but I generally use a #31 or #41 instead of a #30 and #40 respectively. It helps save the hole.
 
Threaded drill bits with a long extension gives you a good visual on angles. Drill 90% through the head and use a spring center punch to pop the shank out.
 
I wish you were close to me, I would come do it and show you my technique. It’s pretty much the same as others here said. I personally don’t like that river removal tool. I have it, and in theory, it should work but I’m really good at going without it. I also like the long bits too, as you can bend them and give them some “english”. Start with a spring loaded automatic center punch, put a bucking bar on the shop head to back up the rivet, and center punch the dimple to make it bigger. Then use a #40 to center drill the rivet all the way through. Check your work and if it looks like it’s going off center, you can work it back centered by eye by drilling at an angle for a little bit. Then step up to the #30 (or 32 or 31 if you have the length to get it in without the chuck hitting things) and just go to the head or less. Then take the #30, and use the back of the drill bit, stick it in the hole and wobble it around, it’ll snap the head off if you are close to the right depth. Then you can punch out the rivet body with another center punch that you have squared off the tip. I find that drilling the whole rivet to a #40 takes the press fit out of the rivet, and they come out pretty easily. If you don’t gundrill the rivet, then they are much harder to drive out.
 
As other as have said, just drill deep enough to pop the head off the rivet. A #30 drill bit inserted upside into the drilled hole will pop the head off with ease. Go slow and don't drill too deep. If you have to knock out the shop head with a punch, have a helper back you up with a bucking bar next to it.
 
I’d like to hear what some of you do to keep your holes centered when drilling out universal rivets.

Scrap steel strap, 1/4" thick. Drill a hole through the end, same size you'll use to remove the rivet. Countersink the hole enough to fit over the rivet head. Stick it in the vise and bend to suit the job. Use with a long drill bit.
.
 

Attachments

  • ScreenHunter_744 Nov. 16 23.20.jpg
    ScreenHunter_744 Nov. 16 23.20.jpg
    14.9 KB · Views: 133
Scrap steel strap, 1/4" thick. Drill a hole through the end, same size you'll use to remove the rivet. Countersink the hole enough to fit over the rivet head. Stick it in the vise and bend to suit the job. Use with a long drill bit.
.

I like that! Thanks, Dan! Might put #4 on one end and #3 on the other!
 
As other as have said, just drill deep enough to pop the head off the rivet. A #30 drill bit inserted upside into the drilled hole will pop the head off with ease. Go slow and don't drill too deep. If you have to knock out the shop head with a punch, have a helper back you up with a bucking bar next to it.

This process has worked well for me. I would say, a thousand times...maybe more.
 
That aileron bracket becomes scrap after you remove it from the wing so you don't need to worry about damaging the hinge bracket while removing the rivets (I think you just need the bearing out of it to put in the replacement). So another idea you could try is using a dremel tool to grind off the manufactured heads and then you might be able to either drive the rivets out or pry them out from the back. I would practice this on scrap of the same thickness just to make sure you can still get the rivet out because it may very difficult after grinding off the heads to see where the center of the rivet is so you may not be able to drill down the center of the rivet if they are difficult to remove.

Or, you could carefully cut off the vertical part of the hinge bracket so that you can properly use the rivet removal tool.
 
That aileron bracket becomes scrap after you remove it from the wing so you don't need to worry about damaging the hinge bracket while removing the rivets (I think you just need the bearing out of it to put in the replacement). So another idea you could try is using a dremel tool to grind off the manufactured heads and then you might be able to either drive the rivets out or pry them out from the back. I would practice this on scrap of the same thickness just to make sure you can still get the rivet out because it may very difficult after grinding off the heads to see where the center of the rivet is so you may not be able to drill down the center of the rivet if they are difficult to remove.

Or, you could carefully cut off the vertical part of the hinge bracket so that you can properly use the rivet removal tool.

Thanks, Tim, for reminding me that I don't have to be concerned about the old bracket. I guess my only real concern then is getting the #40 hole reasonably centered so that I don't enlarge the hole in the shank. I have, indeed, thought about cutting the old bracket off so that I could use the rivet removal tool and may still do that. The top skin still gets in the way of one of the rivets, but just one.

A lot of the replies have dealt with general rivet removal technique. I've removed a lot of rivets and generally do pretty well. My only concern is keeping the drill from wondering off center as I drill.
 
Back
Top