From the F-M Skylarks Model Airplane Club, Fargo, North Dakota
Molding with Carbon Veil
by Jim Varno
It seems as though technology is advancing so
quickly that no one can keep up. Sometimes one gets
discouraged because just when you get good at one
aspect of modeling, the products are no longer
available or new techniques are being used. Each
change requires new skills that must be learned.
I
have found that the old ways of building still work
and it is easier to pick and choose which new
building skills and materials you can incorporate
into your way of building. The key is to keep an
open mind and be willing to change to what will make
your building easier or better without compromising
quality.
One such technique I have learned is using carbon
veil and molding to replace carving and hollowing
out balsa blocks. Carving out the top block on my
Cardinal took several days and a very light, 4-pound
balsa block—which is almost impossible to get these
days. The new method is as follows:
1. Cut and sand a piece of pink foam to the shape of
whatever you want to make (like the top of your new
airplane or a wing tip, etc.).
2. After the part is finished to size, reduce it in
size by 1/16 inch on the top and sides (or 1/8 inch
if using 1/8-inch balsa).
3. Soak your balsa sheet in ammonia for a few hours
until fully soaked in ammonia. Use light, A-grain
balsa.
4. Place the wet balsa over the foam form and wrap
from one end to the other with an Ace bandage. Set
aside to dry overnight at least.
5. Unwrap the Ace bandage and you will have a molded
balsa shell. Now place the shell back on the mold
and repair any imperfections in the balsa.
6. To give the strength to the shell, lay a piece of
wax paper on your bench a little larger than the
inside of your molded balsa, and place the carbon
veil on the wax paper.
7. Cover the veil with a thin film of slow-curing
finishing resin and squeegee the excess resin off
with a flat piece of plastic or old credit card.
8. Place a piece of wax paper over the veil, and
from the center out, use the plastic card to remove
almost all the resin working it out to the sides.
You can’t take off too much, because you only need
enough to stick the veil to the balsa.
9. Next, remove the top piece of wax paper from the
carbon veil. Place the veil on the foam with the
bottom piece of wax paper down on the foam, and
place the balsa shell over the veil. Again wrap the
shell, veil, and foam together with the Ace bandage.
(I also place wax paper between the balsa and the
Ace bandage to keep any resin off the bandage.)
10. When the resin has hardened, remove the wrap and
balsa shell from the foam. The veil now will be
attached to the inside of the balsa and the unit
will be extremely strong and light, ready to glue in
place.
This method may seem complicated but it is actually
faster, stronger, and easier than carving out a
block. Q
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