Paint prep

[Marshall Nay]

I've come up with a simple way of preparing the surface that improves the adhesion of the paint to the plastic. When I remove the mold release I add powdered pumice (volcanic ash) to the mix until it's the consistency of toothpaste. Then I rub it on the figure for about a minute with a soft toothbrush. The pumice is a very fine abrasive so when I'm finished the plastic has a matte/toothy surface. The pumice is inexpensive...I buy it at a ceramics supply shop. It's probably too fussy to be of interest to most of you, but I felt like sharing the idea if there's someone who wants a better bond but doesn't like priming. Peace.

[musketier]

That's an interesting idea,it would be nice if you could post a before and after picture of that process.

[poky]

sounds interesting

[Paul]

It does sound interesting, definately a new one. Doesn´t this " abrasive " dull any sharp details?? Details like the ones on the charging horses in this set for example.
http://www.plasticsoldierreview.com/Review.aspx?id=412

[Fabien G]

so you add that to the water and detergent? or you do it after?

[Keyvan]

nice idea, would be nice if you could post some pictures to show the results.
greets
key

[Marshall Nay]

That's an interesting idea,it would be nice if you could post a before and after picture of that process.

I'm embarrassed to say I still haven't learned how to use my digital camera .
But I can describe the appearance... it slightly lightens the color of the plastic and gives it a more dull/flat/matte quality. And it feels a little less slick to the touch. You might be able to duplicate the appearance with household powdered cleanser, but I think that has a more rough abrasive and might cut into fine details. But it would give you a good idea what I'm talking about.

[Marshall Nay]

It does sound interesting, definately a new one. Doesn´t this " abrasive " dull any sharp details?? Details like the ones on the charging horses in this set for example.
http://www.plasticsoldierreview.com/Review.aspx?id=412

I'm sure on a microscopic level it destroys detail, but nothing noticeable to the naked eye. (What does a clothed eye look like?:shock:) I use a soft toothbrush and scrub in many directions, so it seems to affect the hills and valleys equally. And there's certainly much less detail loss than you'd get with one coat of paint or primer.

[Marshall Nay]

so you add that to the water and detergent? or you do it after?

I add the pumice to the detergent. I've been using liquid laundry detergent* instead of dish soap. I don't use water. I mix powdered pumice into the liquid detergent until it's about the consistency of toothpaste. Then I scrub all over the figure for about a minute. After that I hold it under running water and scrub for about a 1/2 minute until all the powder and detergent are gone.

*(They put agents in dish soap to prevent your hands from drying so I think laundry detergent is a stronger cleaner, but it's probably not that important. And for some reason the laundry detergent/pumice mix seems to spoil and get a foul smell when left exposed to the air, so I only mix as much as I need for each cleaning. If you do use laundry detergent I'd also recommend rubber gloves. With all this I may end up using dish soap. I also tried an ammonia/alcohol mix instead of detergent because they leave no soap film, but it's too watery to make a good paste.)

[Marshall Nay]

nice idea, would be nice if you could post some pictures to show the results.
greets
key

Greets! (see reply to Musketier a few posts above.)

[Fabien G]

thanks for the explanations, I'll try that

[Paul]

I wonder if powder toothpaste might have a simlar effect??

[Marshall Nay]

I wonder if powder toothpaste might have a simlar effect??

I imagine it's too mild... if it was as strong as pumice it seems it would really chew up your gums. I think they sell powdered cleansers with milder than usual abrasives... that might be worth a try.
It's a tricky problem because the plastic really has two problems... one's mechanical: paint doesn't stick well to glossy surfaces. So the pumice takes care of that. But it doesn't solve the other which is a chemical problem in the formula of plastic. I've been experimenting for months and still haven't found a paint or sealer that I'm completely happy with. (My latest experiment is with the vinyl paint cartoonists use to paint on plastic.) I'll post if I ever hit on something I can crow about. Peace Brotha.

[Paul]

Or T CUT ?? I´m not joshing, just thinking out loud.

[Tantallon2]

In Scotland we are currently having deliveries of free volcanic ash

Mind you, what we were actually asking for from Iceland was cash, not ash.

T-cut sounds an interesting technique. But I have to confess that I'm a bit sceptical as to whether techniques like this are really worth the trouble. If you have washed the figures will this technique really make that much of a difference? I don't find paint adhesion being much of a problem these days (certainly not with acrylics).

[Marshall Nay]

Or T CUT ?? I´m not joshing, just thinking out loud.

What's T CUT? (Not joshing, never heard of it.):think: Peace Brotha.

[Marshall Nay]

T-Cut...Car body paintwork finishing product for cutting the surface of paint for a new coat and to produce a high polish on new paint work before final waxing, can also be used to cut the surface back to a decent colour on faded paint , slightly abrasive liguid...
or at least thats the one that I know...

Try rubbing the figure with the primer pen from the 2 part Super glue it has a plastic degreaser.. might work... and theres always some left after you use the glue up....

Better still buy the degreaser I think its Heptane.... I use acetone to degrease its probarbly not as good but is easily available...

Cheers

Thanks for the reply. Yeah, I was just reading about T-Cut and the wax in it would defeat the whole purpose. Using the primer pen's been on my list of things to try. I may be after something that's impossible... but I'd like to find a paint film that I can't scratch off with my fingernail, while still be flexible enough to bend and not crack. Apparently there's something in the chemistry of the plastic that repels coatings, so it's more than a degreasing problem. I read yesterday that in the auto industry they quickly pass the plastic under a blue flame to change the surface structure of the plastic. (A comical mess for us, of course.) I'll post if I find anything promising. Peace.

[Paul]

It's probably too fussy to be of interest to most of you, but I felt like sharing the idea if there's someone who wants a better bond but doesn't like priming. Peace.

It certainly is interesting. I will also be looking

[Marshall Nay]

I've found a product that the auto industry uses to improve the bond of paint to the kind of plastic we use. It's called an "adhesion promoter".
I'll try it and report back...

[Tantallon2]

That's a very good question Ironsides. I must go and experiment with my daughters toy animals to see how tough their paint job is but I don't think it is particularly deep paint coat..