Michael Burbidge

Michael Burbidge

Well Known Member
As I was admiring my newly finished rudder last evening, a chill ran down my spine, when out of the corner of my eye I noticed two extra parts. Upon further examination I discovered that they were the rudder attach strips used to attach the bottom cap to the rudder. Needless to say I spent a sleepless night worrying about how I was going to drill out 32 flush rivets.

So far I've had to drill out only 1 flush rivet. It did not go well. I had a very hard time keeping the hole centered. I've had no problem with the universal head rivets.

I'd be glad to hear tips on drilling out flush head rivets.
 
Drilling rivets

You need to get a sharp drill bit. There is a small divot in the middle of the rivet that is the center. Start drilling very slowly. I try to stay directly above the rivet but sometimes you have to angle your drill bit around to stay in the center. Once you get a good center started then drill and stay directly above it. Keep some pressure on it but let the drill do the work. If you are really good, you can drill the head off and just push the rivet out. Take a piece of scrap alum and put a few rivets in it and try drilling that first. Heres you worst case senerio. If you auger the holes out a little too much you can get those oversized rivets that have a 1/8 shank and 3/32 head or you can drill the holes oversized to 7/64 and use flush monel pop rivets to put it back together. No one is going to notice in the end anyways when it's all painted. Biggest thing is don't sweat it. I once had to drill off a whole bottom wing panel when I forgot to install some parts (duuuuh!). TAKE YOU TIME. Aden.
 
Good advice to practice on scraps.

You've recv'd good advice. I'll just reinforce it by saying to start with practice pieces, this is no big deal but you should be comfortable before you start drilling out the rudder rivets.

I start with a very small drill bit (something like 1/16) to get a good center location, if by chance you don't start in the center with the tiny drill bit you can "walk" the hole back to the center by angling the drill for a second. Then I switch to the full size drill bit and test with the punch to see if the head will easily pop-off. The manufactured head should pop of easily when you have the hole drilled deep enough. If you pry the head off before enough material is drilled away then you may have a problem getting the rivet shank out (this is where material can get bent.)

Relax, practice and don't sweat it. take breaks and don't feel forced to get thru it in one or two sessions.

A fresh/sharp drill bit would be best. Don't pry with much pressure before the head is ready to snap off.

Once the manufactured head has been popped off, I grap the shop head with a small set of needle nose pliers and slowly rotate it while pulling out gently. go slow and make sure your pliers aren't digging into the skin/material.

Good luck,
Stan
 
Last edited:
If you insert a male dimple die into your hand squeezer and leave out the female die, it makes a real good rivet-pusher-outer once the rivet head is removed.
 
Practicing on scraps is a good idea.

I'd also suggest putting it away in a closet for now. Nothing says you need to finish it in the next six months.

Come back to it a year from now when you have a few more skills, and by then you'll feel much better about drilling 32 rivets. You'll have plenty of opportunities to develop those skills in bunches of 1 or 2. Not 32.

So I wouldn't lose any sleep over it. Time is on your side and you'll have the answer sometime in the future.

I've got a few rivets in my HS that were nearly impossible to drive. I finally had to say 'uncle' and put it away. It was the same situation. I finally decided to put it away and trust that I would come up with the answer/tools/skills/whatever-it-may-be to make it happen in the future. I just taped a note onto it and put it in storage. Next thing I knew, I had the answer and I could go back to it and do it right.

So I say sleep easy, wait, and by the end of the project it won't be a big deal. Time is on your side.

Phil
 
On the contrary, I would say that this is an excellent time to learn how to drill flush rivets. Aside from working with scrap material, this is about the cheapest part to completely screw up and replace (worst case scenario). I would much rather scar up my rudder and be able to rebuild it entirely in a matter of days than take a chance on screwing up a wing while learning how to drill out rivets.

Personal choice...

On the positive side, if you've made it all the way to closing the rudder and you haven't HAD to learn how to drill out flush rivets yet, then you're setting your flush rivets better than I did! By the way - I set the first three rivets on the bottom of my rudder without the strip also - drilled them out and started over. Don't feel too bad about it, it happens.
 
One thing that I tried was to take an automatic center punch (the kind that you push foward until they snap) and carefully find the tiny dot in the center of the rivet. then push the centerpunch eight or ten times. when you're done you'll have a nice sized divot right in the center of the rivet. back up the part if you can so you don't dent anything I guess, but that hasn't been a problem for me. the bigger divot will hold the drill bit on center much easier than the stock dimple
 
You must log in or register to reply here.