Posted for "Ron" <ron@baronboys.com>:
Bryan,

Lot's of things, all having to do with trying to get perfect gaps. The
latest use was on the vertical and horizontal stabs on the surfaces opposite
where the counterweights are. I first make the surfaces perfectly flat and
true as possible within the constraints of not sanding into spars or down
into the threads of the carbon. Then I micro on a layer of foam. The foam is
very easy to sand, and if one is very careful, a nice surface with just the
desired gap can be created. Then a couple of layers of very light weight
fiberglass cloth are applied (2 bid of 2 or 3 oz. cloth). The advantage of
this approach is your are using very light weight materials while getting
the desired finish and gap.

Another thing a builder can use the foam for is to micro strips to the
leading edge of the rudder closeout or the elevators. After careful sanding
to achieve the desired shape and gap, on goes the fiberglass cloth. You
could also use carbon cloth or heavier fiberglass cloth in areas where you
might desire a little more strength (such as the lower part of the rudder
leading edge which might be at more risk from rocks thrown off of the
propeller).

That foam is good stuff. Makes it easier to get the desired shapes. I'll be
using more of it than is supplied in the kit.

Hope that helps.

Regards,

Ron Jones
Legacy Kit #181
ron@baronboys.com