top skin won't fit..advice sought

tonyjohnson · #1 10-24-2005, 04:07 PM

I had previously fitted and drill the top skin on my 8A. At that time I did not put the .032 baggage door strip, between the firewall top and the top skin. I did have a .032 spacer between the aft baggage bulkhead and the top skin. I took a lot of time and got the topskin to fit just right before I drilled.

I have since put the baggage door strip in place between the firewall and the top skin. Today I put the topskin on and was suprised that it no longer fits.

Perhaps it was my goof up on not having the spacer in place when I drilled and fitted it. However, I notice that the left and right lower edges no longer reach the matching holes on the side skin.

Another factor is the temperature. I live in Florida and drilled the top skin on in mid summer. Today was the first cool weather we have had since then. It is about 20 degrees different today.

I am wondering if the problem is the extra .032 between the firewall and the skin or whether the skin has "shrunk" because of the temperature difference.

I believe that an additional "spacer" will go between the firewall and the skin, that being the hinge to attach the cowl.

Any ideas would be appreciated.

KirkGrovesRV8 · #2 10-24-2005, 06:03 PM

Hi Tony,
I wish I could offer more help, but I did just go though drilling the top skin on. I hate to say it but I really do think that you needed to have the baggage door strips in place when when you drilled the skin on. On my plans Van's had you use a couple of well placed keeper pop rivets to hold the support strips down. And then you drilled the top skin on taking care that you had everything down tight. I am not sure how you would correct the misagliment. I am sure more knowlegble people will chime in here, but I don't think temp change of 20deg would change the skin enough to not fit.
Best of Luck

tonyjohnson · #3 10-24-2005, 08:04 PM

Kirk,

Thanks for the info. It was a bonehead move on my part to crank up my drill before I understood the instructions in full. I just came out of my shop where I pulled, pushed, cussed and drilled until I have it under control....I think. It won't be pretty, but it will work.

KirkGrovesRV8 · #4 10-24-2005, 08:20 PM

Sounds Good Tony,
Don't worry I think all those little goofs on my plane as well just adds character

All the Best

ericwolf · #5 10-24-2005, 09:42 PM

I agree with Kirk, the spacer is what is causing the fit up issue. The temperature difference has no effect on fit up because the rest of the fuselage is at the same temperature as the top skin. In otherwords, everything that is made out of the same material shinks and expands at the same rate.