Anyone have any foolproof methods for eliminating wood grain in a lightweight painted finish? This would be for non-epoxy finishes as the airplanes I build are 60" wingspan and smaller. I find that I've come close, but have never achieved quite the the desired result.

well for starters you want to seal the wood so the paint won't soak in. It's a huge bonus to get some strength out of your sealer as well. I've seen planes that were painted over bare balsa shatter in a million pieces.

For what it's worth, I have fiberglassed and painted planes that were sub 60" and they flew fine. If you want super light, you might try silk and dope.

carl

Thanks Carl: Any suggestions on mfg. wood sealers/primers and then paint?

Originally Posted by Fast Freddy

Anyone have any foolproof methods for eliminating wood grain in a lightweight painted finish? This would be for non-epoxy finishes as the airplanes I build are 60" wingspan and smaller. I find that I've come close, but have never achieved quite the the desired result.

The absolute best and lightest way is to use silkspan ! Zoom in on the photo below, that's the bottom of my P40 warhawk wing. Most cant even get the tops of their planes that nice.

Rosalie's buffed out P40 Warhawk (1 min 41 sec)

That is beautiful! But I cannot go that way as dope is way to toxic for me to even consider, i.e. toxic odor/fumes, allergies, etc.

Originally Posted by search-n-destroy

The absolute best and lightest way is to use silkspan !

And then what? What technique and materials do you use?

If dope is too toxic you might as well just cover with monokote unless you are running electric.

carl

Nope I'm sure there are other methods.

You may want to consider using lacquer from the big box store. Still some fumes but less than dope. Use it just like dope.

Ken

I've had good results using MinWax sanding sealer, sanding between coats, then topping it off with System III WBPU.

Thanks guys for the input!

Originally Posted by RDJeff

I've had good results using MinWax sanding sealer, sanding between coats, then topping it off with System III WBPU.

minwax sanding sealer is thinned brushing grade lacquer with a touch of talcum powder in it. basically the same as the old school method of mixing some talcum into the first couple coats of dope to seal raw balsa. once fully cured you can put just about any paint over it, but don't put it over anything but lacquer. it will lift any poly or enamel paint, it's solvents are the same as what are found in paint stripper..

Filling the wood grain with sanding sealers and paint does nothing to strengthen the wood. Filling the grain, I suspect will add unnecessary/unacceptable weight..... control line stunt "beauty queens" often had this treatment but those models had lots of power and speed.

To strengthen the balsa I would go with any kind of covering - silkspan is traditional - and, if glow fuel proofing isn't needed, just about any type of paint. A lot can be done with plastic film as covering as well.

Ultra light indoor foam models are painted in water based acrylics - available at craft stores like Michaels - are light and have a dense pigmentation that I suspect would block out any wood grain …. but not add any strength.

Michael in Ontario, Canada

Are you talking solid surfaces? If so, try the old Hobbypoxy “EZ” method. Simply, use 30 minute epoxy! Just apply and use a scraper to press the epoxy into the wood, removing most of the he epoxy. Hobbypoxy recommended a pallet knife. When dry, use a single edge razor blade to scrape smooth and then finish with fine sandpaper. Then prime and paint.
Frank

Here is what you need. Odorless Dope. Mix a little baby powder in with it and brush it on. Sand off until you see the pores of the balsa wood filled with the white powder.

https://www.amazon.com/Eze-Dope-250m.../dp/B004SKODTW