I'm preparing to paint a fiberlgass stock with some polyurethane paint and I'm not satisfied with the masking tape I have used to mask off the inletting. The tape just doesn't like to stick to certain areas of the epoxy bedding.

I was thinking about using Brownells Acra-Release.

I use it for a bedding release all the time. I figured it would work well for any paint overspray in the inletting. I had planned to spray the inletting and barrel channel with Acra-Release and then wipe off any over-spray on the stock exterior with TCE.

Thoughts?

The release agent that Acraglas uses is Poly Vinal Acetate or PVA should work for paint also Alchol will clean it up most of the time.

Use the green masking tape made for painting; not the cheap stuff. But the release agent will work fine too. But I use tape, and use acetone or lacquer thinner to wipe off any over spray; it is quick and easy.

I'm going my primer coat with it masked. Built a paint booth out of a UHaul cardboard robeward box today - will paint when it warms up.

Will use the release agent when I go my final color. Unless of course the primer gray looks good.

Degrease the checkering with any alcohol or lacquer thinner. Use the blue, noisy kid stifling masking tape. Layer enough to cover the checkering panel and then take a stiff hair brush and use it like a hammer with the bristles striking the tape end on. The bristles will hammer the tape right into the checkering and make a perfect reversal pattern on the tape. Then use an exacta knife or scalpel to cut along the border of the checkering. Paint right over the taped checkering panel if you wish. When the paint is dry, retrace the cut around the border with your knife to cut the paint and then lift the tape with a dental probe or other pokety-thingy. If you do your prep work right it's simple with no cleanup. It's all in your hairbrush hammering.

ADD NOTE: This works with wood or synthetic stocks.

You can carefully apply a thick grease, like axle, rather than tape. Use a small stiff brush rather than a finger because you may touch a spot on the exterior of the stock that you want paint to adhere to.
Then after your paint has dried and cured well, simply wipe out the grease that has now been covered in paint.
It's a little messier than tape but works well when tape will not stick to areas you don't wish to paint.

If your very very certain you've given the paint plenty of time to fully cure (a day or two) you can also use mineral spirits to remove the grease.
Do not use anything hotter such as acetone or lacquer thinner, they may damage your paint, very easily.

I've painted dozens of synthetic stocks and getting the tape to stick can be a challenge, at times.
It's still the only method I'd use since everything else would make such a mess and there's real potential with having the other compounds remain on the surface which is to be painted.
Make sure your stock and your tape are quite warm and take plenty of time to cut, trim, stick, push and re-check everything. It takes me about 1.5+ hours to do an adequate tape job. Way more time is spent taping than the actual painting!
Zeke

Oh, and I remove the tape as soon as I can carefully touch the stock (usually within the hour).
This will keep the paint from chipping around the edges and allow you time to carefully scrape any overspray off the critical bedding areas if you have any masking failures.
Zeke

....and I spray release agent on the metal and reassemble the rifle while the paint is still tender. This prevents the paint from curling into the bedding area while it cures and prevents future chipping of the edges.
After a day or two I remove the metal, clean it, clean the stock bedding, light oil metal and reassemble. Done.
Zeke