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<< Lancair Builders' Mail List >>
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Mark,
I'm not an engineer so I don't have a valid opinion on the necessity of
filling all wing imperfections. I just wanted a set of wings that didn't
have any.
I had the good fortune to attend a short seminar given by Jim Rham (sp?)
during which the professional body man who guided Jim in the finishing
process discussed the procedure they had used on Jim's IV-P. As I
understand it, both wing surfaces were slurried with epoxy/micro and then
sanded with 3M 30 inch long board sanders.
Later on I took a friend with about 30 years of auto body work experience to
visit with Jim's mentor (sorry, I don't remember his name) concerning the
process they had used.
With my friend's guidance and more than a little direct effort we finished
the wings using a slurry of West epoxy/micro mixed to the consistency of
toothpaste. West epoxy has a viscosity about two points thicker than water.
It will absorb a lot of micro. With slow hardener West epoxy has a working
time of about 45 minutes at 65 degrees. The epoxy/micro was applied to the
wings with drywall squeegees. Obvious voids were prefilled and allowed to
set up for about 30 minutes prior to filling the entire surface.
Depressions were identified using a 12 foot straight edge. Depressions with
a depth greater than 1/8 inch were covered with a layer of fiberglass over
the epoxy/micro.
Sanding was done using an 8 in. DA sander, an air file and longboard sanding
boards. High spots in the slurry were identified with the 12 foot straight
edge and taken down with the power sanders. Cheap flat black spray can
guide coat was applied to the entire wing and allowed to dry for 24 hours.
Final sanding was done with the long board sanders using 120 and 180 grit
sand paper.
The process consumed almost 5 gallons of West epoxy and a LOT of micro.
Since most of it wound up on the shop floor there is no way to tell how much
weight was added. The aircraft's empty weight at flight test was 2208
pounds with finished paint (Imron) and partial interior. The airplane
stalls power off pretty much straight ahead at about 60 kias.
Merrill Smith
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LML website: http://www.olsusa.com/Users/Mkaye/maillist.html
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Please send your photos and drawings to marvkaye@olsusa.com.
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