Pat Harris’s Arixtra, pictured at a contest in
Redmond OR, features House of Kolor paint.
thinned finishing resin and left to cure
overnight. Residual epoxy paraffin was
removed from the cured resin with
isopropyl alcohol before a light second
coat of resin was applied to fill the
After fiberglass repairs, the fuselage
was bumpy. Obvious high areas were
blocked off. Jim suggested applying a
guide coat before the primer. In the
past I had only applied a guide coat
after primer. Block sanding the guide
coat flagged low spots and aided in
sanding off more of the original primer,
further lightening the airframe. Guide
coating early saved at least one primer/
I repeated the cycle of spot filling,
guide coating, and block sanding
several times before I brushed a
thick coat of Klass Kote primer on
the repaired areas as a final filler. As I
suspected, the primer revealed more
problem areas needing repair.
After sanding away most of the
original primer, the fuselage, which
was completely stripped, patched, and
leveled, was ready for primer. At this
point, it weighed even less.
I sprayed the first, full primer coat. I
spotted in all of the low, guide-coated
areas several times before I gave the
entire airframe a nice, even, thick coat
of primer. When it was tack free, I
applied another guide coat and left it
Using dry 220-grit sandpaper in an
“X” sanding pattern, the primer was
sanded until the underlying substrate
was barely visible. I discovered and
repaired a few more problem areas.
Finally, an even, light primer coat was
sprayed then wet-sanded with a 600-
grit sanding sponge.
The ready-to-paint fuselage weighed
roughly what it weighed after I
removed the finish.
In my next column, I’ll discuss
building a spray tent and squirting
some Klass Kote paint.
National Society of Radio Control Aerobatics
115 Model Aviation MARCH 2014