Submitted by Anonymous on Wed, 12/02/1998 - 08:15 Forums: LML Archive From: William T Bartlettby way of Marvin Kaye <marvkaye [at] olsusa.com> <wtbart [at] olympus.net> Subject: SS firewall etc. Date: Wed, 02 Dec 1998 03:15:22 -0500 To: <lancair.list [at] olsusa.com> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> >I also used a >tool (used to finish lightening holes) to put a 1/4 inch beveled edge around >the firewall. This tool is about $12 from Aircraft Spruce and consists of two >closely spaced rollers on a handle allowing it to be run along the edge of the >material so the bevel can be formed. The benefit is to stiffen the firewall >material to prevent near-edge oil-canning and provide a way to hide the fiber- If you don't have time to wait for the tool you can make one. Take a scrap of 1/8" micarta or similar (hard nylon, old cable pulley) and hacksaw a cut perpendicular to the edge about 5/16" deep. Round one corner of the cut to about 3/16" radius. Oil the edge of the sheet to be beveled and insert it in the cut and pull the tool around the sheet holding it against the rounded corner. You might have to go around a couple of times. >Subject: No hard points?? >I couldn't help but notice that the manual recommends that your cut & fit >the fiberfrax to the firewall, attach all the layers with silicone, and >then glue the stainless sheet over the top of them the same way. I'm >curious about how much that fiberfrax compresses when you torque down the >engine mount attachment bolts... seems to me that the insulation would >compress considerably and allow the stainless sheet to dent inward under >all that bolt pressure. , or am I worrying about a non-event >again? > > <Marv> Yes you are! Beside the engine mount bolts you are going to put lots of bolts through that firewall. Bill N7WB