RC Groups

RC Groups
    Painting and Finishing Tips
        Question Light filler for glass

#1 Highride Jan 30, 2013 03:46 PM

Light filler for glass
Need some recommendations for a lightweight filler to cover minor imperfections in glass.

I'm pretty good at glassing but occasionally end up with those small areas where I didn't wet sufficiently to completely fill the texture of the cloth. (Nope, I don't use a vacuum rig) I normally don't spot these until I have a coat of primer down. I've tried things like light spackling but cannot get it to hold in those minor imperfections.

Some ideas? The lighter the better.


#2 TomCrump Jan 31, 2013 08:06 AM

Many times, the use of automotive high build primer will do the trick. Just spray it on, and block sand the area.

If that doesn't do it, an automotive spot putty will fix you up. Prime the area, then apply the putty. After it dries block sand and then prime. The putty does shrink, so a few applications may be necessary.

I buy these products from a professional auto paint store. You should have something similar, in the UP.

Duplicolor high build primer. is available at almost any auto parts store, but I don't know if they would have spot putty.

#3 Highride Jan 31, 2013 09:13 AM


Thanks. I'll give that a try. I was just over at NAPA poking around the other day. I'm sure I'll find that Duplicolor product or something close. Always learn something new. (By the way, we do have color TV and dial phones up here now--big grin)

I'm an e-sailplaner almost exclusively but do stick build from time to time. Last stick build was a Pat Trittle short kit, the Pilatus Porter.

Think you've been getting much more snow than us. Our second year of a "snow drought" and that is depressing. Killing the snowmobile and sport shops. Got about 4-5 inches yesterday so looks like my wife and I can get out on the x-country trails. Not groomed of course.

Year before last, we came down to Harbor Springs and did the Little Traverse Wheelway. Overnighted in Charlevoix and headed back. Nice lazy ride and wonderful scenery.

Thanks again,


#4 TomCrump Jan 31, 2013 10:22 AM

Hi Dave

Do you have iddoor plumbing ? LOL

We had 6'' the other day, and another 4" last night. Another 4" is expected by Friday. You can have mine. LOL

The high build primer isn't too heavy, but the spot putty may be heavier than you desire.

Good luck on your project.

#5 kenh3497 Jan 31, 2013 09:22 PM

A trick the DLG guys use is to slightly thin epoxy with alcohol and smear it on the offending spot. The thinned epoxy will soak through the unfilled weave and bond to the surface below and in your case fill the weave. In most cases, at least for me, the cloth is stretched tight enough when laying down the first coat of epoxy so it has not bubbled. I just didn't get enough epoxy in that spot. A second or God forbid a third application takes care of the problem.


#6 Andy01 Feb 01, 2013 04:45 PM

Micro balloons mixed with epoxy resin ? It doesn't come much lighter than that :)


#7 Highride Feb 05, 2013 03:52 PM

Thanks all...

I used the high build primer because the imperfections were so tiny. ( my wife says I'm too picky. Us RC guys "picky"?)

I've used the microballoons and epoxy in the past but that was in construction or to fill a void during repairs.

The technique I have not tried is the thinned epoxy. Think I'll experiment with that on some scraps.


#8 jhaywood Feb 06, 2013 11:19 AM

they make a lightweight polyester glazing compound. Spot Lite by evercoat is one product. Squeegee on with a razor blade and then sand lightly to blend. It may take one or two applications unless you want to spread it heavier and block sand it all off including the surrounding primer...Its great since it cures in 10 minutes and sands easy

#9 Highride Feb 06, 2013 05:09 PM


Another new product for me. Thanks. Might be a good idea for some experimentation.


All times are GMT -5. The time now is 06:24 AM.