In the manual, section 5, page 4, it states:
"Use the appropriate rivet or screw as a gage when you machine countersink. When the rivet/screw is flush, you are done. If there is going to be a dimpled skin riveted onto the machine countersunk surface, adjust the machine countersink tool a few “clicks” deeper than flush. This will make the rivet/screw sit about .005” below flush when dropped into the hole."
If you use a dimpled piece of scrap material, the dimple (and the hole) will most always come out oversize.
Bruce Reynolds
Rv-6A
Thanks Bruce
I’m sure it says that, however on page 7-12 of the instruction manual it also says, (somewhere about the middle of the page) …….
“Disassemble the Aileron. Deburr all of the aileron parts. Machine countersink the A-903 spar flanges (this will prevent bowing the spar that can be caused when dimpling since it is .040” thick), the 3/32” rivet holes in the A-908’s, and the A-911.
Use your dimple test patch to adjust the countersink tool for the A-903 and A-911."
The “dimple test patch” was something I created back during the tail section build from the scrap pieces provided. I, as did others, followed the instructions and countersunk too deep because they recommended using the dimple test patch. There should be a little warning or reminder added to the instructions. They put in reminders for less critical items!
A little later in the instructions (page 7-13, above the word FLAPS) Van’s put in a reminder to scuff the powder coated parts (if they are to be painted) and yet no reminder about the possibility of over countersinking. This is gonna sound cynical but, Van’s has given a reminder to do something that, if not done correctly, will in no way generate further income for them. However, they have no reminder about possibly screwing up a part or two that you must replace if not done correctly. And who do you have to go to for replacements? Yup, that sure sounds cynical!
Now please don’t go yellin’ at me ‘cause I did a little Van’s bashing, I’m just being me and me is opinionated. Besides, lesson learned and the cost was minimal. Having never built a plane before - I gotta go by the instructions.
But thanks again. I'll go back and review all that information to refresh my memory.