E-902 spar dimpel

Hi,

Yesterday dimpled the E-902 spar to be able to attach the E-906/E-905 rib. The comment from the manual is that it need to be a flush rivet because the horn will be behind it.

Today I noticed on a website from an RV9 builder that he countersunk them. Is it wrong to dimple the spar?

Thank you

Dimple

Not sure the part of your empennage that is , but a basic rule of thumb is dimple .040 and less , counter sink .40 and above . .040 is thick enough to countersink but Vans has you dimple it in a few places ( at least on the 8) .

Dimple

g zero said:

Not sure the part of your empennage that is , but a basic rule of thumb is dimple .040 and less , counter sink .40 and above . .040 is thick enough to countersink but Vans has you dimple it in a few places ( at least on the 8) .

Click to expand...

I think if you already dimpled it's probably ok, assuming as mentioned, it's not more than .040". You can also use a countersink bit in a hand tool to work the dimple just a tiny bit. Vans actually uses this method on the rear spar skin holes.

It appears to be just fine. Newbie stress for nothing.

Thank you!