# Touch-up paint on models?



## Alter-Autos

My girlfriend suggested I paint my Revell '37 Ford convertible the color of our Saturn. I liked her suggestion, so I checked Dupli-Color's Web site. They don't have that color in a spray can, but it is available as touch-up paint. Is it possible to open up a touch-up paint pen without getting a bunch of shavings and shards everywhere, and what would I use to thin it?


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## djnick66

Automotive paint can be used on models but its usually some sort of lacquer that is hot and will craze the plastic. You need to carefully prime the model with a suitable primer. Airbrush or spray can application is pretty much mandatory. You would probably thin the Duplicolor stuff with lacquer thinner.


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## Dyonisis

djnick66 said:


> Automotive paint can be used on models but its usually some sort of lacquer that is hot and will craze the plastic.


 That simply isn't true! I've used NITROCELLULOSE LACQUER on models, and never had that happen. This is the hottest stuff on planet earth to paint anything with! Unless you're painting with methylethyl ketone, you shouldn't get any type of crazing from polystyrene. This is the reason that polyurethane was invented as it never truly hardens. If you've ever tried to polish it out you'll know what I mean. It gets small knots in it if you use a pedestal buffer, and it leaves lines from the cotton buff itself because the finish is so soft that it doesn't have any reisistance. Polishing pads with micro-abrasives, and hand polishing techniques are the only thing that helps to prevent this from happening. The buffing machine is great for light swirl mark removal, but the heat generated from it can ruin polyurethane in minutes! I don't recommend using it for guitars, or anything that you have to polish - it's only good for furniture as this is what it was originally intended for. 

Primer was invented for allowing a more secure tack, or adhesion with metal. The drawback with actual lacquer is that it expands, and contracts at a different rate than metal, so it checks, or cracks in a spider web, or checkerboard pattern. With plastic which is much softer you don't have that happen. Duplicolor doesn't make lacquer as all their products have an acrylic base. This is safe to use as I buy this now since it's so much cheaper, and more readily available locally than lacquer. Most of the paint stores are phasing it out in favour of environmental products. I need to get all my paint projects done with lacquer that I'm going to do, or get enough to last me for a few years, and store it away. There's no telling when they will outlaw it forever! 

I'd punch a hole into the can if it was empty only to get the mixing ball out for other projects, but being full you don't want to do that! Just get a small soup can (Campbells' works best), make sure it's clean, and dry. Cover over the top of the can with a plastic sandwich bag with a hole cut into one corner. Use that corner to put the spray head through. Then put the bag over the mouth of the soup can with the spray can head inside the bag, and spray a little at a time. This keeps you from losing a lot of paint when spraying outside (which is what you want to do) when you drain the spray can. 

I taped the head seal under that spray button on the spray can to the plastic bag to keep from leaking out, but that turns messy after a while. Now I just spray directly into the can, but it still loses a lot of paint to the air, and I get paint all over my hand, and the outside of the spray can from the overspray, and the force of the propellant being pushed into the soup can. You'll also want to keep the spray head at an angle inside the can above the paint as high as possible.This keeps the paint from splashing back at you while you empty it out. Just don't tape the bag to the soup can so that the gasses can escape while spraying.

I use the tall two quart soup cans as this allows me to spay without the splashing effect. It has enough space inside to drain a full can of paint into it without a lot of mess even without the bag over it. I'll use the bag over the spray can again the next time. I know that this all sounds like more effort, but the results are priceless! After all this you can pour the paint from the soup can very carefully into a jar that you can store this in until you're ready to use it. This is the only way I know of to successfully decant paint for airbrush use. With the bag acting as a buffer, you don't get all the mess that you normally would without it.

~ Chris​


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## s.moe

Hey, Alter-Autos.....You should have NO Problem using the Dupli-Color Automotive Lacquer paint on your Revell '37 Ford kit....I've used their paint's for quite some time now with no problem's....Even without using a primer as a base....Checkout my '38 Ford pick-up build in MOE's Garage,,Post #352š....It was done without primer and with Dupli-Color spray paint.....Even the Clear is Dupli-Color....

As far as "opening up" the Dupli-Color Touch-up paint pen....You should be able to remove the insert,(usually white, red, or yellow in color) were the brush goes down into the tube, by prying it out....Then you will be able to Pour the paint out....As for thinning it,, I'd do like djnick66 suggest's and use Lacquer Thinner....

GOOD PAINTING.......


MOE


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## CorvairJim

A good primer coat is *ABSOLUTELY ESSENTIAL* whan working with any "Hot" paint such as lacquer. Chris says he's been successful with nitrocellulose lacquer, but that stuff hasn't been available fo a few decades now so it's a non-issue. My son got completely turned off to model building when he ignored me when I told him to prime the body of his second model before painting it, and the spray touch-up paint he used crazed the plastic so badly that I considered it to be beyond salvage.


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## s.moe

Jim....I do agree, That using Primer on a build, is a good Idea...Before applying any Lacquer Paint....It's alway's better to be safe than Sorry....

But, as far as the Dupli-color Automotive Paint....I haven't had any problem's just applying it straight on the bare plastic....I don't know,, But, Maybe it's not as "HOT" or That I've just been Lucky...... 
And, That's not to say That it won't happen in the Future....However, I do alway's TEST any paint that I'm going to use, on Scrap piece's of spure and plastic spoon's to See How it's going to React and look....

But to be Safe....YES, It's a good Idea to alway's use Primer, Before applying Lacquer.....


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