how to clean plastic?

I'm guessing that you are talking about a fresh kit and noy one that you are re-doing. Before I paint, I wash the parts in warm soapy water.Try using a liquid dishwasher soap, Dawn, Ajax,etc.


Kee Your Powder Dry!

A wash in warm water with Dawn works for me.

2 way to clean plastic,
First one before i even start sanding or anyithing, wash model in dish detergent and water. with a good rinse.....

2nd, after sanding and stuff?
I will take the same stuff that my paint thinner is made of after giving a nice top coat of paint, and wipe down the model.... let dry for about 2 hours, then I will wash off with pure water, then just before painting a 2nd top coat, i will use a tack cloth (for a general wipe down)and also use my airbrush(for a general air spray down) with no paint in the airbrush and spray off the model, and then RIGHT BEFORE I paint the model i put it up, away from my paint chamber , I will use a simple "misting bottle" AFTER I have spayed and thoroughly clean my paint chamber, and mist my (spray area, paint chamber), and then spray paint, if I want that GOOD of a finish, if i am spraying battle tanks or whatever, I don't bother with all that, I just spay the "crap" on there. Tanks are supposed to LOOK painted.... Cars, well, You can spend a million bucks on a finish for a car, but they can still be crushed by tanks

I use alcohol. It dries faster than water and dissolves the grease. Then blow everything off with compressor air.

Also, I only clean parts right before painting. I don't see much sense in cleaning them if you are going to handle them and sand on them so I wait until right before they are painted.

Music, so you never paint any of the parts of your subject before you do your main paint job or put it all together? Don't you have problems with release? And what about your base coat/coats? I personally have had to many problems with release to not clean the parts, not to mention I get a better tack with my glue if I remove the release...
Just my

I paint things in the largest sections that I can. By that I mean, for example, the complete assembled fuselage with wings, empennage, etc. By the time I get all that assembled it is covered with finger grease, sanding dust, etc. It just wouldn't much good to clean everything beforehand.

For glue I normally use either Tenax or Ambroid (whichever bottle I grab) and they melt the plastic, along with anything on it, so grease isn't a problem with them. When I use CA I do normally clean the parts beforehand with alky. As you said, the release agent does have an affect on CA.

Would it be bad to use an acetone based nail polish remover to clean plstic? It looks like that dissolves grease well. Or would that make it tough for the enamel to adhere to the plastic?

Acetone can dissolve plastic if you aren't careful with it. It evaporates so quickly it's seldom a problem, and you are right in that it will get the grease off, but it can also make a mess.

I never was sure if I'd been taken for a ride, but the folks who make the Polly line of paints and other paint-related items, once marketed, and may still market, a product called "plastic cleaner," and it was a wonder. It may have been nothing but a mixture of everything listed above, but the big bottle took everything off the bare plastic, from fingerprints, to sanding sludge to release agent, and made the surface perfect for painting. Yet it was totally gentle to the surface. It came in very large (for a model produt) bottles, say, a half-litre or so. I lost mine, and haven't found any more. But it was worth the six or seven dollars I paid for it, I would say, in convenience.
Tom

DON'T use acetone. For environmental reasons ALONE you should refrain from using it, but it also can jack-up your hands from prolonged contact and it will often leave a residue.

TMU you should use Dishwashing detergent with a long soak (some say to scrub, but I'm unclear as to that wisdom), then use gloves from there on out to handle the kit.

Not that I've been back into this for very long, but that was my recollection of the way to do it. As for the gloved treatment, well, that's a bit extreme, IMO. Just wash large assemblies again when you're ready to paint (allowing a day or two to dry, mind you).

Just my opinion. YMMV.