To Drill or Not to Drill

JoeG · #1 04-17-2006, 09:09 PM

OK... So I'm still a newbie... I searched the forum for questions of this nature but didn't find exactly what I was looking for. Pictures speak louder than words. So look at this...

Does the left rivet need to be replaced? I know the picture isn't that great. And it sort of exaggerates things due to the angle and lighting. Case in point, the rivet on the right is nice and flush. Most of my rivets are flush, but I can feel this one protruding slightly if I swipe across it with my fingertip.

Back in the old wood-working days I used my fingers to find imperfections that the eyes couldn't discern. I'm somewhat inclined to drill this out and replace it. But I can be overly analytical sometimes, and I don't want to screw-up an "OK" rivet if it's not necessary. Oh, and this is on the bottom side of the H. Stab. Not that that makes any difference.

Thanks,

scard · #2 04-17-2006, 09:19 PM

I say leave it. Unless you are just totally board and think you can drill it without touching the hole at all with the drill bit

. I know I was WAY too anal about this kind of stuff in the beginning.

Robert M · #3 04-17-2006, 09:24 PM

Joe - your an amature aircraft builder - don't expect perfection! That looks great to me, I only hope I can do that good of work when the time comes for me to start.

jcoloccia · #4 04-17-2006, 09:27 PM

I like your website, by the way. Some people are persnickety and want every rivet absolutely perfect. For the occasional on like this, I'd just leave it the heck alone. Rivets are particularly difficult to get out when they're not on the edge of your piece because you don't have a good way of backing them up. Often times, you'll enlarge the hole or otherwise screwup the hole as you're trying to get it out. I've especially noticed this with dimples holes. I think as the rivet expends, it expands the dimple slightly also so even if you do drill it out perfectly, the hole's still going to end up a little bigger than ideal.

I dunno...I'm from the "we're not making jewelery" camp. Just my opinion.

az_gila · #5 04-17-2006, 09:35 PM

Joe.... leave it alone...

If you want more specific information on the flushness of rivets, the Mil Spec. gives actual numbers....

http://www.home.earthlink.net/~gilal...ec/rivet_a.htm

For flush rivets, strength is OK

Unless otherwise specified on the engineering drawing or specification, flushness limits shall be 0.010 inch above to 0.005 inch below the material surface.

Your rivet looks like less than 0.010 inches above the surface. It can be shaved if you want, but not needed....

gil in Tucson ...who prefers actual numbers....

JoeG · #6 04-17-2006, 09:59 PM

Quote:

Originally Posted by az_gila

gil in Tucson ...who prefers actual numbers....

Thanks Gil. Perfect timing with your response. I was looking for the Mil Spec when you replied.

I think I'll leave it be...

RScott · #7 04-18-2006, 05:35 PM

I have learned the hard way that way too often I make things worse by drilling out rivets. I now only drill them out if they have a serious problem. A rivet that isn't set quite right stays. Van's will tell you their engineering analysis shows you could build the plane using only every second rivet and it would still be safe. Of course they don't recomend it, and what would you do with all those extra holes?

You can shave a rivet that is too high. One trick my AI showed me is to put double sided tape on the bottom of the countersink cage to keep it in place when shaving a rivet. Check the various catalogs for rivet shavers.

From what I can see in your photo, I wouldn't mess with it, but I am not a prize winning builder and don't expect to be.

rzbill · #8 04-19-2006, 10:15 AM

Leave it alone. For two additional reasons not posted above.

First, after you move further into construction and store the tail for awhile, you will probably forget about it and never think of it again. Good rivet....

Second, on the chance that you are accidentally reminded about it many months later, you will certainly be in a better position to either decide to leave it or have a much higher skill level for drilling rivets and be able to do it flawlessly

JoeG · #9 04-21-2006, 09:24 PM

Quote:

First, after you move further into construction and store the tail for awhile, you will probably forget about it and never think of it again. Good rivet....

Good point Bill. I won't likely be drilling it out later since that would mean replacing it with a blind rivet. That's the main reason I was considering it now.... before I close out the HS with the rear spar.

I will leave it alone...

Thanks to all for your input. MAN I LOVE THESE FORUMS!