Most Commonly asked Questions & Building Tips
An easy way to keep this Tips page
handy is to print it out! Just set your printer properties to 'Landscape',
and then print a set of full-width Building Tips to use at your building
As you might guess, we field hundreds
of questions about our building techniques, and receive calls about small
problems modelers come across when they are building. Typically, we hear
them over and over again. These are usually very easy to solve, because
we've had the same problem ourselves and have found the best solution to
it. Once again, this page is here for YOU....to help save you time and
trouble while building your models. Write us with your
Q: I'm getting ready to
sheet my fuselage, but I can't see how in the world this sheeting
is going to roll on and stay around these rings with the glue-joints that make
up the fuselage.
Am I doing something wrong?
A: No, you're okay. ( In fact, this may be the Number One question asked by our
modelers. ) First of all, you never want to sheet just the 'rings'.
You will sheet the designated areas in one solid piece on the left or right
sides of the fuselage. It's a round fuselage, and all of our fuselages are tear-shaped
from front to back, and many have a break and a bevel in the front like our GeeBee Z or R-2
models. The glue (joined) area of the 'rings' on certain models may be slightly higher than the
other parts of the fuselage. You want to take a LONG sanding board and work
those joints of the 'rings' down until the whole fuselage is one long smooth line, and as we said, teardrop
shaped, uninterrupted until you reach the break for the bevel in the
front. DON'T sand the bevel or the break, leave them squared off just as
they are. You're just sanding foam here, so take care not to sand too
much, you can bring it down to a teardrop shape with a minimum of effort.
Once this is done, you'll easily see how you've made it so that the sheeting
will roll on in one long sheet with no problem whatsoever! Again, do NOT
sheet the rings individually, this can and will affect the strength of the
Q: I'm having a lot of trouble finding the 3M
2060 Lacquer Masking Tape you mention in the building Techniques Page. Can
you help me find some?
A: You bet! In fact, it has been a
BIG problem, because the 2060 really is THE tape for the job, but fewer Home
Depots carry it than we originally thought. We've been searching for a
dependable national outlet where you can find it, or at least order a few rolls
if they don't have it on hand. Well, we found it! Sherwin-Williams,
the house-paint stores you can find from coast to coast, stock the 3M 2060
Lacquer Masking Tape as standard stuff in most of their stores. More
importantly, they have a company-wide stock number for it, #155-3874. This
means you can call them, and if they don't have it, they can order it in for
you, and you don't have to buy a whole case of 36 rolls, which would be a tad
inconvenient for most modelers.
Q: I have finished sheeting some of my flying
surfaces, But I've noticed that some areas of balsa lifted near the edge of the
flying surface. Is there
something special I should do with the Foam Bond to make sure that little
flap stays down?
A: Once you've used the Foam Bond, you
won't need to use it again. Foam Bond is a water-based glue, and that's
the secret here. You can use any other water-based glue to hold that edge
down. We use Aliphatic Resin, like Sig-Bond, Tite-Bond, or Elmer's Wood
Glue. Simply work some of
that under the flap, and use some Lacquer Tape to hold the flap down to the
edges. Near the edges, it's better to use Aliphatic Resin than Foam-Bond,
as Foam-Bond remains rubbery and does not sand easily. Aliphatic Resin sands very
well in those spots, making it ideal.
Q: On top of my
GeeBee fuselage, behind the cockpit, where the two balsa sheets join, there is a
tight turn where the balsa doesn't want to stay down. I also had the same
thing on some of my warbirds. What's the best method for fixing this
A: That's an easy one. Use
some Aliphatic Resin under the flap, spray the outside of the flap with a 50/50 mix of
ammonia and water. Then strap the flap(s) down with some Lacquer Tape,
just as in the last Q& A. Those spots are a little tougher, and
sometimes the balsa is a bit harder than you'd like it to be, and won't bend as
well as it should. That's why it's so important to use the spray mixture
to penetrate and help the bending. If you use the mixture, it also helps
the wood to dry and stay in the shape you've bent it into.
Q: I built my rudder,
but when I started to fit it, I noticed that the rudder is taller than the
vertical stab area of the plane! Help!
A: Relax! The rudder is cut
the same height as the fuselage, but once you've added the capping to the full
round edge of the rudder you've made it a different height by adding thickness to
the top and the bottom. Once you add your capping to the top of the
vertical fin, you'll fill in most of the difference. The bottom of the
fuselage, however, doesn't call for any capping, and that often leaves about
3/8" of difference. You can add some scrap to the bottom until they
equalize in height, or you can add a little to the top of the fin. I'd be
surprised if anybody noticed 3/8" of height added to a fin & fuse that stands 16
or 18 inches in height! If added to the bottom,
you could also use hardwood to help mount your tailwheel gear. If you're
striving for absolute scale outline, then trim off the rudder
bottom a little and re-cap that area so it matches. That's the beauty of
Q: I have capped
everything once and then sheeted over it and trimmed the edges square, why do I
have to go back and cap everything again? Isn't once enough?
A: No, once is not enough.
Once you get ready to cover your plane, you're going to have to round your
leading and trailing edges, etc. If you tried to round the edges now with
just the first round of capping in place, you'd sand through the sheeting to
foam all over the place. That's a BAD thing! By adding the second
layers of capping, you'll add enough material there so that you can round the
edges nicely without fear of sanding through to foam.
Q: My friend already has a Jack
Devine GeeBee model like the one I'm building, but she keeps telling me NOT to sand my balsa too much. I want my
plane to look great like hers does, how can I do that if I can't sand it until
A: Now THAT is an excellent
question! What if I told you that your plane can look AWESOME and you
won't have to sand the balsa much at all? Sandable sealers are available,
like Sig's Lightweight Sandable Sealer. Once you are ready to do some
smoothing, apply the sandable sealer, and let it dry. It's lightweight,
and fills and smooths the balsa in ways sanding NEVER could! After a light sanding,
you'll have removed almost NO balsa, but your model will be as smooth a baby's
bottom! Remember, foam sheeted models are exoskeletal, that means their
strength comes from the combination of the foam, the exterior balsa shell &
the capping, and the proper
adhesive. Take away any of those things, and you'll cause a severe
strength problem. So, tell your friend she's right! Her plane is probably
the toughest plane at your flying field because she built it right! You
to her! (Yep, the woman is right....as usual!) By the way, uh, where is your
Q: I sheeted one side of my wing last night
but not the flip side, and when I came back today, my wing was warped! Did
I ruin it? If not, how can I fix it?
A: It's not ruined. Did you ever
watch the westerns where the rawhide ropes shrink as they dry and tighten around
our hero's hands? Well, once you wet down the balsa with the ammonia &
water mix, it loosens it up and makes it more pliable, but like the rawhide in
the westerns, when it dries it shrinks like crazy, pulling your wing into a
warp. You can save it, though. First, take your 50/50 ammonia &
water mix, and spray it on the entire outside of the balsa that dried, and make
sure you wet it thoroughly. Let it sit for a good 20 minutes so the balsa
can loosen up again. Next, roll the Foam-Bond onto the flip side and
get it ready for sheeting, and sheet it the same way once the Foam-Bond goes
clear on the foam and the balsa sheet. Make sure you keep the side you
first sheeted moist until your wing is fully sheeted, then let both sides dry
together. On smaller surfaces where you might have applied too much
tension during sheeting and ended up with a slight warp, wet it down the same
way, and with the warped side up and the ends up on something, place a weight on
the middle of the warp, enough to bend it back slightly past center. Let
it dry there, and when you remove the weight, your warp should be history.
Q: I've built foam
wings before, but I usually use the method where I tape the sheets together, put
some kind of glue on them and the wing core, place them in the shucks
( Note: The
shucks are the remaining pieces when a foam wing is cut from a block. The
wing fits like a glove inside of it. Ours are shipped inside their
'shucks' as well.), and lay a sheet of plywood over it and weight it
down with concrete blocks, and walk away
until it's dry. Why can't I build mine this way? It sure looks like
it would work.
A: Yes, it can be done that way,
but we a have a few reasons why we don't use that method. We use Foam-Bond
because it lends a second kind of strength to our models, and that is
flexibility. Now, one of the properties of Foam Bond is that it dries
rubbery, and doesn't sand well. That's why we join our sheets prior to
sheeting, we don't want Foam Bond to ooze out from between the sheets and create
a sanding problem. But...We DEFINITELY want to use the
The simple fact is that our wings just don't fail. There is really only
one difference between our wings and other foam wings sheeted with balsa, and
that is the adhesives we use! Foam-Bond makes all the difference.
Next reason; if there is a warp in a wing-core, then it's also in the wing
shuck, they're the same piece of foam! If you lay a warped wing into a
warped shuck and glue it and weight it, it's going to come out WARPED, same as
it went in! No amount of arguing can change that, it's pure physics!
Now, when a wing and the sheeting are rolled with Foam-Bond and allowed to dry, once the Foam-Bond
goes clear it is time for sheeting. So, you spray the OUTSIDE of the
sheeting with a 50/50 mixture of ammonia and water to make it pliable.
Here's the beauty of this method: Say the wing core is warped, for
whatever reason. No problem! You press the leading edge of the wing
down onto the sheeting on a straight, flat, smooth surface, and then keep
downward pressure as you roll the wing core backwards onto that flat, straight
surface. When you've finished the rolling-on, the wing core is absolutely
straight. You then do the other side the same way (in the same session,
and let both sides dry together, straight as an arrow. That's right!
Your warped core would actually come out as straight as the table top! And
then it dries that way, period. So, our method used with our Foam-Bond
adhesive guarantees consistently straight wings, more strength, and also acts as
a concrete block repellent, keeping concrete
blocks OUTSIDE of your shop!
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Jack Devine Models
14906 114th Ave. N.E.
Kirkland, WA 98034 - 1031
Business and Information line: 1- 425 -
822 - 8130
Toll-Free Order Line (Not for information): 1- 800- 897- 0717