Cowling installation question

[sblack]

I am looking at the cowl installation drawing on the RV4. It shows shimming the piano hinge to give about 0.050" step between the skin and the cowling. However the cowling I have, which is old (kit is 1990) is about 0.10" thick, which will put a 50 thou aft facing step all around the firewall. I don't recall seeing such a step on most finished RVs. Every body would want a smooth transition there.

A lot of them have been built, and I have never built one before, so am I missing something? Is my cowling unusually thick? How much of a step should I allow for between the cowling and the skin aft of the firewall to ensure a flush fitting cowling?

I am not putting this in the RV4 section because all of the RVs have a similar cowling installation.

Thanks

[n82rb]

what I did was mount the hinge to the cowling and made the shims to fit the cowling flush or slightly below the skin. then finalized it with a light coat of mico on the cowl to get it perfect.

bob burns
RV-4
N82RB