Testing dimpling 0.032" thick material for #8 screws - Day #2 - 3 hours

Well tonight, Good news and good news. The replacement wing tank skins arrived from Vans. And I gave it another shot on the old wing skins and all 42 test holes where successful.

Using the dremel. I wrap a small square of adhesive back 600 grid sandpaper on a mandrel that i made (Cut the brush end off of a dremel accessory). I then insert it in the hole that I've drilled and while turning on the dremel I move it in a circular motion to help ensure that I do not make an oblong hole.

 
Using the felt tip and polishing compound to debur edges. I found after a few holes that this method doesn't really do a great job to remove sharp edges of debur. I don't think that I will repeat this process on the new skins.


 One old wing skin dimpled like mad!!!! Lots of test dimples in this one. but I think I have found the secret. Now to apply it to the new skins.
 
How I'm checking for cracks


I was glad to see that the new skins arrived, but I do have some knots in my stomach as to my ability to dimple these holes. Not wanting them to sit in the box too long, I opened them up and set them on the bench.


If anything, I thought that I should at least start advancing them. I may feel shaky about dimpling, but I am confident that I can at least drill out the holes. So I de-vinyled the edges and dug out the drill.  

Drilled all holes to #20 slowly working my sizes up starting with a #30 bit. No I await the #19 reamer to arrive.