masking over paint

I concur completely with what the others said about preparing your surface, etc.

Re the tape, I have had excellent results over Tamiya acrylics with Tamiya's own tapes, both the regular yellow tape and the white "for curves" varieties. Both are nicely low-tack right off the roll. I will generally mask with as narrow a strip as I can get away with -- either from the roll, or pre-cut into narrow strips on a piece of glass -- and then 'fill in' the masked area with paper, Silly Putty, or whatever works.

Last thing before I spray, I go back and check that all the tape is burnished down along its full length, eliminating those pesky 'underspray' blooms.

I've never had the 'chemical changes' marks mentioned above...but I make it a point to remove masking as soon as is practical to avoid the likelihood of such problems. Actually, removing the tape before the sprayed paint is fully cured and hardened seems (in my experience, at least) to give a cleaner edge with less chance of chipping or flaking.

Cheers

Bob D

What is best to put over the paint so the masking tape wont pull any paint off.

Will any clear coat work?

 

A clear coat will just be an extra layer of paint that gets pulled off when you remove the masking.  The clear coat will bond great with the paint underneath it, but if the paint isn't adhering properly to your model, its still gonna come off.

I use decanted Tamiya Grey Surface Primer that I thin with MEK on everything (even the tiny parts) and don't have issues with paint pulling off with the masking material.  The MEK is compatible with the Tamiya primer and gives it extra bite on the plastic.

For masking these days, I stay away from tape altogether.  Tapes of all different kinds tended to leave a mark on the paint due to what I think is a chemical reaction caused by the adhesive on the tape.  There were always these random, sharply-defined areas of a slightly different sheen left behind when the tape came off when viewed at the right angle under bright light.  So, now I'm using Tamiya's masking sticker sheets that I just cut to the shape I need for masking.  No residue or chemical reactions with those and they're nice and thin, so they easily conform to even tiny recessed areas in a surface you're masking.  Amazingly easy to work with for masking canopies too.

What is under the paint, and what type of paint that you use is more important than what's over the paint when masking. You can mask paint directly with no problems. But... if the paint has poor adhesion qualities, it doesnt matter what you put over it, the paint has a good probability of pulling up when the masking is removed. Enamels and lacquers will usually adhere to bare styrene quite well. But acrylics are a toss up, and some brands require a primer for best results. In that case, your choice of primer will make a difference and is quite important.

I use regular masking tape,however I always remove a lot of the tack by putting the tape on a smooth surface like my fridge and pulling it on and off a few times.

As far as paint,a good lacquer or enamel base primer helps,but the tape and how it is applied makes the big difference,

For small areas,I also use post it notes.