&*$%#@$ Mr. Masking Sol Neo !&%@#$

acrylic is pretty easy to get off. Windex works well as does 409.

As to why it came off could be a couple of things. Did you wash the parts in soapy water prior to prming? Did you prime? What did you prime with? How long did you let the paint dry before masking?

Never worked with that product before but have used other liquid masks with out much issue though I do prefer tam tape.

If you don't happen to have those handy, I believe rubbing alcohol will also remove acrylic paint with no danger to the plastic.  For masking panels, I also much prefer tape or post-it notes.

Groot

Thanks, guys. I did not prime, but the paint sat for a week before I applied the masking fluid. I always get scared when I prime or add layers or hairspray/camo that I'm going to get a bad layer or maybe some orange peeling so try to keep the layers down. But looks like it may have come back to bite me this time.

Does anybody ever lay down matte/satin/gloss varnish layers between steps as a safety net to try and protect the paint? Or will this make future layers or acrylic not behave?

Thanks, as always, for the help.

Cheers,

-Robb

Unfortunately, Mr Masking Sol Neo and similar latex-based masking fluids like Humbrol Maskol don't like to play with acrylic paints.

You may get them to behave by applying light layers, but your mileage may vary. Apply thickly and it'll eat right through an acrylic base coat. 

Ahhh – Good to know, Phil_H – Thanks for that info. I wasn't sure if it was just me or if it really was that it doesn't get along w/ acrylics. Looks like it's back to the careful Tamiya-Tape-Masking for me!! Thanks again.

Turns out that I had two problems:

1.) Not priming made the acrylic not stick to the plastic as well as it can

2.) Mr Masking Sol Neo is really harsh on acrylics.

As a test, I had some parts that were still painted WITHOUT primer. I tried masking them with Tamiya tape instead of Mr Masking Sol Neo, and everything went fine.

For the parts that I had to strip down and repaint, I primed them with Mr Surfacer 1200 and the colors on top of the primer are now MUCH more durable than they were on top of just plastic. Additionally, Tamiya tape's straight edges give a much cleaner line, no matter how neatly I applied Mr Masking sol.

Tamiya Tape + Priming = success.

Thanks again to everyone for the suggestions and help!