AN426 Not Completely Flush

In my RV14 wing build, there are two items that lack perfection and bother me (I'm keeping the ones that don't bother me silent!!!)

On the spar with the countless nut plates, the flush rivets that hold the nut plates on are ever so slightly proud. Probably 0.002 - 0.004; one or two clicks above just perfect. They were just perfect when I machine C/S them but something in riveting technique left them slightly high.

Same sort of thing happened in two rivets AN426AD4-8 on the rear spar inboard doubler where one side of the rivet is ever so much higher than flush.

How critical is this? I know I have an excellent rivet strength by not being too deep with the C/S. But it isn't perfectly flush. I could try and make perfect with a rivet shaver but that risks messing things up. What is the tolerance on this part of the process?

I've almost decided it doesn't matter because the skins for the fuel tanks will screew down into all the screw holes and the slightly proud nut plate rivets won't make a difference if the skin is properly broken. On the other hand it may look puckered where it is down tight in the screw location and held up next to it by the slightly proud rivet?.

Who has some good advice on this. Seems the risk of messing things up is worse than the benefit of getting it perfect.

So, if the advice is to dress it flush - rivet shaver or small grinder or ???

thanks!

Build on... no worries.

Proud rivet

First try setting the rivet again. What sometimes happens is the rivet is pushed back toward the head just before it swells. Either the bucking bar pushed it back or the squeezer was not pushed hard enough against the factory head. JMHO. If that doesn't make it flush, you can rub it a bit with scotch brite so there isn't a sharp edge. I would leave it after that. Every time I mess with a minor issue it becomes a major one and adds to my scrap pile.

wirejock said:

Every time I mess with a minor issue it becomes a major one and adds to my scrap pile.

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Man, that is great advice. My scrap pile is loaded with minor issues I turned into major projects.

wirejock said:

Every time I mess with a minor issue it becomes a major one and adds to my scrap pile.

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When talking about only a few thousandths, I agree.... this is very good advice.

When the access plates are screwed on, you will never be able to tell the difference.