A warning to all those who have been following Tony K's advice in using a
hairdryer to improve epoxy flow during layups. Remember that heat rises!
When I was completing the underside leading edge wrap-around, the heat from
the dryer rose onto the bare foam behind the masking tape causing the foam to
shrivel. This wasn't immediately noticed until after the layup was turned
over. About a quarter of the length was affected, about 30mm wide and, at
worst about 4mm deep. As this is a critical part of the tailplane profile, I
was worried that it would be difficult to restore it. Thankfully, the remedy
(discussed and approved with Roger at Europa) is easy and simple.
I located the equivalent leading edge jig (the bit that is cut off to give
access to the wrap-around). After filling the recess with dry micro, I laid
clingfilm (Saran wrap) over the filler and squidged it down using the jig
block to achieve the original profile. Apart from one or two very small areas
requiring filling immediately before the next layup, the profile is perfect.
One other tip that might be useful:
If, like me, you have difficulty cutting the wet cloth to a straight line
close to the masking tape on the underside of the leading edge, over cut it so
that the rough cut edge is on the masking tape itself. When cured, do not try
to remove the tape immediately but feather the edge as per the manual using a
long sanding spline. Eventually, as the cured epoxy and glass is removed, the
leading edge of the tape will be consistently exposed allowing the masking
tape and rough cut edge of the layup to be easily pulled off. Although this
takes a bit more sanding, there is a much reduced risk of sanding into the
foam. The final result is a beautifully straight, consistently feathered edge
for the next layup.
Just make sure that all the masking tape is removed though!
Chris Vowell (Kit no 345)
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