I was wondering if a person can just sand and paint a balsa model airplane? Do you have to fiberglass it first? Thanks

No, you don't have to, but the wood grain will show through. If that doesn't bother you, go 4 it.

Ditto. Another thing I'd like to point out is that without glassing, the painted balsa may not be fuel proof. This of course is no biggie if your model is electric.

Another aspect of covering, andf covering materials, is that these 'films' and 'cloths' also add stregth and structure to the model. that nbeing the typical iron on covering, and teh typical 'glass sheet' of fiberglass or silk.

The wood parts are really just a shape; a form, a skeleton, and teh covering materials add the require 'stress' to hold it all together.

As in: Can I paint my tail (stab rudder, etc..) in stead of covering it? it's a solid peice of wood.

The answer is usally no., as the paint does not add any structure, were the coveing materials will.

have seen a few painted in color,a few painted clear,I wasn't impressed but the clear planes looked different,just make sure the final coat is fuel proof if using glow fuel.

Ok thanks for the info. I think I will take the time and glass it.

Many planes have been painted with dope and no covering. It takes a lot of coats to seal the grain which is the primary reason I use fiberglass as an all-wood structure is normally strong enough without covering - at least the ones I build. The covering gives a nice, even base for finishing.

Also, dope is fuel-proof, but you don't have to use so much as to completely seal the grain. 3-6 good coats will make your plane plenty fuel proof, but even with 6 coats the grain will probably still show.

If your thinking of this for a trainer plane I would think otherwise. All of the fancy painting on wood is fine for scale models and such (that dont fly all that great to begin with). But paint, fiberglass, dope all add a lot more weight than covering.

Not true. A well done paint job (on a sport model) - especially using dope can be as light or lighter than Monokote. Generally the reason people think paint is heavy is because they start out with sub-standard wood work and then cake on primer and paint trying to conceal things that could have been resolved by sanding.

But I agree that for most people paint is heavier because of what I just said. My point is that it's not a universal truth - just happens more often than not.

When you get to scale, on the other hand, there are a lot of things contributing to the weight other than paint. On scale models, flying qualities are considered secondary.

PS. I agree that painting a trainer probably isn't the best thing to do. Just makes you cry more when you crash it. I silked and doped my trainer and crashed it on top of a school. It exploded.

CafeenMan is right on. I've been building powered model aircraft since the 40's and I always prime and paint the balsa surfaces using aircraft dope. Strengthening is unnecessary and I don't believe iron-on film does much of that anyway. Fiberglass adds strength but also a lot of weight, which may be appropriate for very large models but usually not. My current procedure is a prime coat of laquer based sanding sealer, two thinned coats of clear dope, sanding lightly between coats and two sprayed coats of color dope. The resulting coating is lighter than film and looks good. If butyrate dope is used, it is fuel proof. There are also no seams to lift.

Has anyone painted the inside of there planes? I am building a US60 and was thinking it would look good if the inside matched the covering.

Hi all... Here's a thought.

I almost totalled my US+40, and rebuilt the engine cowl from balsa. I decided to paint it (LustreKote) to both match the black monokote, and to be fuel-proof.

For those interested, I first sanded, sanded, and sanded some more, then used white primer, then 4 light coats of black.

This is what it looks like... (note that the grain is still visible).

Maybe people can comment on how it could have been done better, but also, this will show what it looks like when done "just basic".

gus

(note that the grain is still visible).

At very little, if any, weight penalty the wood can be covered with light weight Japanese tissue before finishing.. This procedure covers the grain, absorbs less dope, and if a tissue color near the desired finalcolor is used reduces the required number of color dope needed. Color is heavier than clear.

Nice job Gus!

I am building a GP patriot jet and wanted to glass the fuse. Since it has a lot of contour and aerodynamic shape , the monokote on my other patriot has a hard time holding the material on. It seems like it always wrinkles and since the jet is 95% solid wood I thought of glassing the whole thing. Would this add too much wieght? Thanks

No. If you apply the glass properly it will be very light.