Garage Guy
Well Known Member
Some rivets attaching the underside horizontal stabilizer skin to the HS rear spar on our RV-6 are loosening and smoking. I understand this is a pretty common problem if the skins were machine countersunk too aggressively.
I want to deal with this before it gets much worse, but it's not totally clear to me how best to attack the problem. Anyone with experience on this I'd like to know what, short of reskinning, fixes this so it stays fixed.
Here's one question. If the rivet head is sunk below the skin, does it make sense to ream out to #30 and replace the AD3 rivet with an AD4? I realize you wouldn't deliberately machine countersink for a 4 rivet in .032 sheet, but if it's already almost there, would it make a better fix at this point? Or, is it better to stay with 3's, and just use a slug when squeezing to make sure they are set tight?
Here's another. Would it make sense at this point to bond the skin to the spar? What I have in mind is drilling out all the rivets, cleaning the faying surfaces, laying on Scotch-Weld 2216, and re-riveting. It seems to me that would keep the joint from working loose again. But maybe there's a good reason not to do this?
Thanks in advance for any help!
--Paul
I want to deal with this before it gets much worse, but it's not totally clear to me how best to attack the problem. Anyone with experience on this I'd like to know what, short of reskinning, fixes this so it stays fixed.
Here's one question. If the rivet head is sunk below the skin, does it make sense to ream out to #30 and replace the AD3 rivet with an AD4? I realize you wouldn't deliberately machine countersink for a 4 rivet in .032 sheet, but if it's already almost there, would it make a better fix at this point? Or, is it better to stay with 3's, and just use a slug when squeezing to make sure they are set tight?
Here's another. Would it make sense at this point to bond the skin to the spar? What I have in mind is drilling out all the rivets, cleaning the faying surfaces, laying on Scotch-Weld 2216, and re-riveting. It seems to me that would keep the joint from working loose again. But maybe there's a good reason not to do this?
Thanks in advance for any help!
--Paul