This is for all builders, not necessarily just the original poster.  One
word of caution on all of this wonderful heat shield information....it's
not weightless.  I took about 7 pounds of heat shielding out of N891JF's
cowling (the KR2).  The total cowling weight started out at 21 pounds
(compared to N56ML's total weight of four pounds), and about a third of
it was heat shielding. On top of the fiberglass was silicone, then
fiberfrax, more silicone, and then some thin aluminum blanket.  It was
quite an ordeal to strip it all out, but it made it quite a bit lighter.
 And you know what?  Not even the paint is discolored where it was all
removed!  It's also worth mentioning that the N891JF's cowling is very
thick, with way too many layers of fiberglass, which makes it even more
insulated, but also makes it downright brittle.  If I didn't have so
many other irons in the fire, I'd pull a mold off that cowling and make
a CF one that weighs a fraction as much.  Maybe after I retire!

By contrast, N56ML's (KR2S) cowling is two layers of carbon fiber (with
an extra "X" reinforcement for the relatively flat top....just like the
hood of your car), and weighs 4 pounds total, including the aluminum
attachment hinges.  No heat shielding, super thin, flexible when
disassembled, fairly oblivious to exhaust pipe heat.  I have had exhaust
components in direct contact with it, and all it does is burn the epoxy
out of the matrix....the CF is still there (although rather anemic from
a strength standpoint).  My point is that by providing a little bit of
clearance, and maybe a small bit of heat shielding strategically placed
only where it is really needed, is all you need.  Don't overdo it.  I'd
bet serious money that Ken Rand had no such thing in his KR1!

There are many safety measures that are very prudent in our airplanes. 
I'm not sure that heat shielding the cowling is one of those...

Mark Langford, Huntsville, AL
ML "at" N56ML.com
www.N56ML.com



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