Paint & Finish
For automotive paint and finishing topics.
Masking tape stripping paint
Kentucky, United States
Joined: April 19, 2007
KitMaker: 759 posts
Auto Modeler: 4 posts
Posted: Friday, June 19, 2009 - 01:49 PM UTC
Hi guys,

I'm working on one of my first cars and have run into a problem. When I peel up the masking tape I have applied, it takes off the paint all the way down to the plastic.

I washed the parts before painting, but did not prime. My original plan was to go with a mauve color, so I sprayed a mix of various flat MM acrylics. This didn't give me the proper color, so instead of messing around with it any further, I went with plan B, which was an overall coat of gloss black. I applied two coats, again using Model Master Acryl, and proceeded to mask around various details using Scotch tape (the "green label" kind). Before applying it, however, I first stuck it to my shirt to remove some of the tackiness, then applied it and burnished it with a toothpick. When I removed it later, it pulled the paint up.

So what am I doing wrong? I can fix the problem relatively easily, but would like to know what I may have done wrong so that I don't make the same mistake again. I have used this tape before without any problems, so I don't think it is the problem, but I'm open to any suggestions.

Alberta, Canada
Joined: January 19, 2008
KitMaker: 6,743 posts
Auto Modeler: 64 posts
Posted: Sunday, June 21, 2009 - 02:22 AM UTC
Hard to say what is the cause of the paint lifting but it could be the paint wasn't fully dried , to thin of coat , No primer ! If you start with a flat base paint it will not get a good bite to the plastic . There has to be tooth for the paint to adhere to .

I have had this problem with acrylics before but not with enamel . I would strip the paint off and start over and spray primer down first and let this dry for a day or two , before spraying on the colour coat take a piece of tape and do a lifting test in a hidden area . If all is well then spray the body colour . Let this dry for a day or two before any more masking is to start . In most case this way the paint lifts . I'm sure you prep everything right . since you have done this before and no trouble at all .
New York, United States
Joined: December 07, 2004
KitMaker: 1,888 posts
Auto Modeler: 806 posts
Posted: Sunday, June 21, 2009 - 09:36 AM UTC
Samuel i would strip the paint first as Terri said than i would sand the plastic with 6 or 800 grit sand paper to give the paint something grab onto, priming would be a good idea before using your acrylic paint than make shore it's well mixed if it comes from a jar you know all that thick stuff in the bottom of the jar or it won't stick, after applying your paint let it dry overnight and before you mask if you can apply a Model Master clear coat it's much stronger than acrylic that may also help. I don't like masking with tape but when i do i use blue painters tape i mask with laytex mould builder. Good luck.
Indiana, United States
Joined: November 12, 2006
KitMaker: 285 posts
Auto Modeler: 47 posts
Posted: Tuesday, June 23, 2009 - 03:31 PM UTC
One problem with acrylics is that they tend to dry to the touch very quickly, but may not have fully cured for some time. Especially if you agressively burnish into the surface to get the tape to seal.

Surface prep as already mentioned is the other. As molded, most plastic is very smooth. Even free of mold release, it may allow water to bead very well. This could be a sign that the surface is too smooth for a good bite.

As a final note, you might discover that masking on certain senstive paint finish shouldn't be done with masking tape. In order to get masking tape to seal really well you do need to burnish it down a bit at the very least. This is putting a lot of force into the paint finish underneath. It might be better to find a lower tack masking medium. There are various types at hobby and art stores. A bit pricey compared to good old masking tape, but worth avoiding to strip and repaint.
Illinois, United States
Joined: August 30, 2005
KitMaker: 3,289 posts
Auto Modeler: 1,620 posts
Posted: Tuesday, June 23, 2009 - 04:19 PM UTC
I've taken tape and stuck it on my pants leg then applied to the model...lessens the stickiness of the tape.
Also, how are you pulling the tape off? This should be done about 3-5 min after the paint goes on so the edges settle down when it dries...and I pull the tape at a 45 degree angle down and away from the freshly painted area to lessen the chances of paint pull.