Stuck Liquid Mask Question

Lonewolf · Post by **Lonewolf** » Tue Apr 01, 2014 2:02 pm

I'm posting this question for Cydonia, who's at work at the moment. He's texting me with the information so I can post it.

He's working on a styrene project and applied a base Tamiya clear green acrylic coat. He used two layers of latex-based liquid railroad mask that he got while he was in Florida over the holidays. He applied a primer (automotive enamel) via rattlecan, followed by two coats of lacquer a day or two later. He said that he waited about an hour between the coats of lacquer.

Now, here's the problem. The liquid mask has been on for about two weeks, and he's trying to remove it but it's being a royal PITA.

He says the mask is supposed to rub off or peel. It comes off very stubbornly with the blunted end of a toothpick, and usually scratches the bottom paint. When it does come up, it comes up as bits and pieces. He's also tried using an Xacto around the edges with the same result.

So . . . . what should he do to get this stuff off his model, without damaging the paint?

Mark Yungblut · Post by **Mark Yungblut** » Tue Apr 01, 2014 2:35 pm

If the mask is at all tacky then this might be the answer

http://www.cutting-mats.net/rubber-ceme ... 7AodQB4AWQ

Lonewolf · Post by **Lonewolf** » Tue Apr 01, 2014 9:23 pm

Ken can't tell if it's tacky or not. It's had one coat of enamel primer and two coats of lacquer put over the masking.

seam-filler · Post by **seam-filler** » Wed Apr 02, 2014 1:39 am

Try the rubber on the end of the pencil - that's worked for me in the past when I've left liquid mask on for too long. Dilute ammonia might also soften it, especially at the edges which might help it lift off.

dizzyfugu · Post by **dizzyfugu** » Wed Apr 02, 2014 4:22 am

It could be that the latex mask reacted with the paint on top of that - happens after some days, had a similar problem some time ago with Humbrol's masking fluid. The rubber becomes relatively hard and adheres vehemently to the surface below, making the peeling process REALLY troublesome.

My advice: avoid this through instant de-masking, as soon as the paint is dry enough. Adding some "handles" in the masking fluid (e .g. strips of paper) that make peeling off easier is also an option, but that won't avoid the danger of having the masking stuff "dry out" after long periods on the model.

Cydonia · Post by **Cydonia** » Wed Apr 02, 2014 7:43 am

Found a partial solution: hot soapy water. Softens the mask enough to scrape it off with a dental pick. Of course, it also pretty much removes the underlying paint, but I can touch that up.

Kylwell · Post by **Kylwell** » Wed Apr 02, 2014 12:09 pm

This has happened with every liquid mask I've ever tried. Now-a-days I use it to seal butted tape joints but not much else.

Lonewolf · Post by **Lonewolf** » Wed Apr 02, 2014 12:20 pm

Don't forget about using Silly Putty.

http://www.starshipmodeler.com/basics/rd_silly.htm

Yeah, I know . . . shameless plug, as I wrote the article back in 2007.