Wrong rivet: Leave it or Drill it Out ?

[sglynn]

Darn, I put some 3.5 length flush rivets in the trailing edge of the wing where they were suppose to be 4.0 length. Does it matter? I have a nice shop head, just a little thin. Should I drill out the few short rivets and replace them with the slightly longer ones? Drilling out is a potential problem. Is it worth it. What is the general opinion of builders with regard to using a rivet that is 0.5/32 to short?

thanks

[mcencula]

I see you're building a -7A, so I'm going to assume that these are in the area where the doubler is for the aileron brackets. If that's the case, I'd leave them. There are quite a number of AN470AD4 rivets holding those brackets on, so the flush rivets add little to the strength. Also, the flush rivet holes will now be enlarged somewhat and the -4 length will be more likely to bend sideways. You have to weigh the risk of tipped rivets against the knowledge that you have some out of spec.

One alternative may be to use some of the 7/64 oops rivets. Those would be far less likely to tip over and you could get a good shop head on them.

[Vlad]

It matters a little. Just be careful next time.

[Greg Arehart]

I agree with Vlad. Unless there are structural issues, then they would be better off left as is, particularly if you have good shop heads. The rivet specs are not always perfect anyway, so the key is having a good shop head. My opinion.

greg

[roee]

Originally Posted by sglynn

Darn, I put some 3.5 length flush rivets in the trailing edge of the wing where they were suppose to be 4.0 length. Does it matter?

Like others have said, it depends. How undersized are the shop heads? And you have to weigh that against weakening due to drilling out the rivets.

Anyway, for future reference, consider the rivet length call-outs on the plans as only a first guess in any case. What really matters is that the shop head will come out within spec. So you should always choose the correct rivet length using a rivet gauge. Most of the time the call-outs on the plans will prove accurate. But sometimes you'll find that you need a longer or shorter rivet than shown on the plans.

[az_gila]

Originally Posted by roee

Like others have said, it depends. How undersized are the shop heads? And you have to weigh that against weakening due to drilling out the rivets.

Anyway, for future reference, consider the rivet length call-outs on the plans as only a first guess in any case. What really matters is that the shop head will come out within spec. So you should always choose the correct rivet length using a rivet gauge. Most of the time the call-outs on the plans will prove accurate. But sometimes you'll find that you need a longer or shorter rivet than shown on the plans.

...someone quoted the actual specification....

It's not even a bad rivet (3/32 numbers here) until the shop head is under 0.038 inch high - since the magic "perfect" rivet has a head height of 0.047 inch, that is a lot of tolerance - it will look flat.

http://www.rvproject.com/MIL-R-47196A_MI.pdf

...from my scan/generation via Dan C's web site...

[zzapp]

This was very informative though I can't find it in the VAF archives to properly cite it.
OOPS, found it: http://www.kilohotel.com/rv8/rvlinks/marvelrivets.html

[az_gila]

Originally Posted by zzapp

This was very informative though I can't find it in the VAF archives to properly cite it.
OOPS, found it: http://www.kilohotel.com/rv8/rvlinks/marvelrivets.html

...uses terms such as "grossly" instead of actual numbers. A few micrometer measurements would have been informative.

Who knows exactly what he tested....