Liquid latex masking problems

I have tried using liquid latex for masking, but keep running into the same problems time after time, so I don't know if it's my technique or the product itself. The product is "Incredible White Mask" liquid frisket from Grafix. It's really nothing more than latex and ammonia. The problems are lack of crisp edges/peeling of the underlying paint at the demarcation line. On one hand, the peeling could be attributed to the latex over an acrylic base. However, it does the same over enamel, both resulting in the ragged edges. The ragged edge problem appears to also stem from bleed-under. One of the original problems I had was trying to trim out areas such as canopy framing after a coat of masking. As I cut around the framing, the latex would shrink, peel back and lose the seal on the plastic, then the paint would bleed under it. I tried heavier coats and the problem became worse, thinner coats resulted in insufficient coverage. After it's dry, rubbing across it to remove it is where the greatest peeling problems arise. Is there a different liquid masking product I should be using, or is it merely my technique? I realize I can use foil for canopies, but I thought this route might be easier to work with, plus I have other masking tasks besides canopies where foil or tape really aren't feasible. As I stated in another post I'm starting to do some large figures, and foil/tape won't work (too many tight compound curves). Thanks, MV.

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Reply to
TimeTraveler658
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I've had similar problems; I find it almost impossible to cut, and even if I don't cut the latex it can leak under the edges. Solution: use that superthin black hairline tape to make your outline, then fill the surface area behind the outline with latex. No more bleed, no more need to cut. But that only works on relatively even surfaces where the tape can stick.

Seb

Reply to
Seb

Ammonia-based stuff over acrylics is definitely a Bad Idea. Ammonia is commonly used to clean dried acrylic paints...

Reply to
Serge D. Grun

That's part of your problem. Ammonia can soften acrylic paints, causing the liquid mask to meld with the paint.

Don't try to cut it. As the knife cuts across it, the latex is stretched and loses its grip on the surface, and since there's no adhesive, it won't stick back down no matter what you do.

When you apply the liquid mask, brush it on carefully around the edges so it won't need trimming. Making a smooth edge with a brush on a curved surface is no more difficult than cutting one with a knife.

Heavier coats take longer to dry, giving the ammonia more time to soften the acrylics underneath. Multiple thin coats should work better, but you'll have to brush carefully so as not to harm the previous coats of mask.

Other things you might try:

- Clean the model before painting, and use a primer, so that the paint will stick to the model better and be less likely to be pulled up by the mask.

- Let the paint cure for at least a week before masking so that it's at maximum hardness.

- Use gloss paints instead of flats. Liquid mask won't stick as strongly to the smooth surface, so it's less likely to pull up bits of paint.

- Use very narrow strips of tape to mask your demarcation lines, and use liquid mask to fill in the rest. The narrower the masking tape, the easier it is to make it follow tight curves. (To get narrow strips, lay a piece of masking tape on a clean sheet of glass and cut it with a razor knife & straight-edge.)

- Try Parafilm instead of liquid mask. Stretching it properly can take a bit of practice, but it works great once you get the hang of it.

Reply to
Wayne C. Morris

i use freeman beautiful skin peel off masque. it is in the cosemitic section of most stores. it does not attack a gloss finish, it smells good, and you can share it with the ole lady.

BCNU jack

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Reply to
jack

I'd use Bare Metal Foil for canopies. An X-acto swivel knife and some magnification does wonders.

As to your need for a liquid mask; I'd try a different product. Microscale makes a blue colored water soluble mask that should work better over paint; I usually use two coats. If you're close to a shop that specializes in R/C aircraft there's a few products in that field which should work better than the one you've got. Just check for a non-ammonia base. hth

The Keeper (of too much crap!)

Reply to
Keeper

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