#8 dimple

prkaye · #1 04-08-2007, 06:37 PM

I'm not sure my #8 dimple die is resulting in deep or "tight" enough dimples. I've used my pneumatic squeezer (for the #8 holes along the edge of the tank skin where it meets the wing spar), set them so the dies close and cranked up the pressure. I can't get any deeper #8 dimples with these dies. It's actually like the dimple ends up being too wide, so in the area really close to the screw it isn't flush (but across a larger area it is flush). In the attached photo, the skin shown was completely flat before dimpling. As you can see, the screw is flush with the height of the skin an inch away from the screw. But within 1 inch of the screw the skin is lower than the screw head.
Is this common? Either I'm being overly fussy, or I need a new set of #8 dies... just can't decide which is correct

Suggestions?

Will Womack · #2 04-09-2007, 08:59 AM

The instructions specifically tell you NOT to use a pneumatic squeezer for the #8s. Use a C-frame and they come out perfect

Jalanci · #3 04-09-2007, 10:08 AM

Occasionally when I check some rivets, I get a proud one. My solution so far is to countersink to the proper dimension a bucking bar and use that as the receiving die, then I take a similar rivet and tap the skin with a pneumatic set at a low pressure, to the die, check and see if it's flush. I did the counterweights this way and it worked out ok.

JoeLofton · #4 04-10-2007, 04:15 AM

I whacked my tank screw dimples in the C-frame like the instructions say, which left a divot around the dimple. I then squeezed them with a hand squeezer (Main Squeeze) and most of the divot was removed. Go figure.

Thanks to Smitty's web site for the squeezer tip.

Joe Lofton
RV-9A - working on the wings