Top Forward Fuse Skin Trimming

[lr172]

I am wrapping up my Fuse skins and had a question about best practice. I am unsure how to create a trim line for the forward edge of the top forward skin. This will form the edge where it meets the top cowl. Do you just make a pleasing line that follows the flanges on the firewall? I guess it only needs to be straight and pleasing as the cowl will be trimmed to match. Just looking for pearls of wisdom from those who have been there before.

Thanks,

Larry

 

[BillL]

I am puzzled, maybe others too. I am building a 7, so it is prepunched, but the forward top fuse skin on mine is cut and punched ready to install. At least from the perimeter treatment. As it is trial fitted the leading edge overlaps the firewall tabs, so there is nothing to trim for me. It may be different for a 6.

Hope that helps.

 

[JonJay]

You have it correct. This is an area that typically requires shimming in various spots to get the transition to the cowling to look its best. Remember, if you are doing this per plans, the hinge is part of this assembly as well. You will want to shim below the hinge between the firewall flange and the hinge/top skin. The amount of shim and locations depends on a lot of factors. You can use a piece of scrap aluminum the same thickness of the cowl flange to simulate the fit. Trial and error. Shims should be feathered on the ends to make a smooth transition and of a length that you can capture at least two rivets with appropriate edge distance on the ends of the shim.
While you are at it, the other area to focus on is where the top skin overlaps the main longeron on the sides. Spend time on these areas with shims and you can dramatically affect how the cowling interface looks.

SAFETY NOTE - the Firewall Flange is very, very sharp. It sent me to the hospital for stitches....

 

[lr172]

Thanks for the suggestions Jon.