Oops Rivet Length

[Aero_Octaveus]

If you choose to use and oops rivet for the skin. Does the length stay the same or do you increase the length of the rivet due to the larger shank diameter (So you maintain the formula of "Rivet length (sticking out) = 1 1/2 x rivet diameter"

For example. If you rivet the skins with a 426AD3-3.5 rivet, would the equivalent oops rivet be the NAS1097AD4-3.5, or do you increase the length and go with a NAS1097AD4-4?

Or am I over-thinking this?

[BobTurner]

use the 1.5x formula, the shop head is for an 1/8" rivet.

[plehrke]

Re-gage (using gage for 1/8" rivet) the tail sticking though and see if it need a different grip length. It may stay the same or it may go up one.