Auburntsts

Well Known Member
I've got the MILSPEC RV-10 CAMLOC cowling kit and was reading through the instructions concerning the receptacle mounting strips and there's no mention of using shims. If I were using hinges, the plans direct you to place .020 shims between the hinge and the fuselage which I assume is to create enough depth to account for the thinkness of the cowl so that the outer surface of the cowl and fuse are flush when the two are mated. Since I'm using camlocs, now I'm wondering why the camloc mounting strips don't need a shim as well. I'm obviously missing something here. So, the basic question I have is do I need shims or not to account for the thinkness of the cowl?

I did a search and didn't find a definitive answer.
 
You should need the shim strip. You can measure thickness of the cowl at that point and thickness of the skin/firewall combo.. if you notice a difference in those two measurements (as I expect you will), then you'll need to shim it. This is independent of which method (hinge/camlocks) you use..
 
I did two things in an attempt to help alleviate, if not prevent, the "bulging" or pillowing that some report in flight, along the top of the cowling between the fasteners, due to air pressure. We'll see if it works or not :)

I put a *thick* shin between the firewall/skin flange and the Skybolt receptacle strip...I think it was .050...had a friend cut them to size with a large shear. Then, I laid up fiberglass along the inside aft edge of the cowling, different numbers of strips depending on what was needed where, until the cowling matched the top skin (actually, all the way around), figuring a really good thick fiberglassed aft portion of the cowling would be stiffer and resist the bulging.

We'll see...if I ever get this thing finished (sigh) and flying...