Do you have to use primer paint?


H

HurricanesFEC

New Member
Preparing to paint a kato sd8mac with scalecoat II6oz spray can, do I really need primer?
 
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It all depends on what you are painting. If I am painting a brass locomotive, I will definitely prime. If it is a plastic diesel shell, it would depend on what color I am using. The important thing is to have the shell clean. I will usually wash it good with just soap and water and let it dry thoroughly. I paint my locomotoves yellow, which is a lousy color for coverage. These shells I will prime, but if I am using a color that covers well, such a black, red and aother darker colors, I will not prime, but just apply a few very light coats of paint until the coverage is even. I use an airbrush. I guess this could also be done with a rattle can, but I do prefer an air brush. By applying a few very light coats, the details will not be overcome by a thick layer of paint. After the model is thoroughly dry, decals can be applied and then I will seal everything with dull coat. I will usually apply weathering before the final dull coat application so the weathering is also sealed.
 
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I too, primer everything. With brass, it helps to provide the paint a surface to cling to better. With plastic a good neutral primer helps with the number of coats needed to cover the color the body is molded in.

The primary colors, red, yellow, and blue actually have a hard time covering black. Put a neutral primer over black, and the number of coats needed to cover the body, without there being a "shade" change evident in the body cover, goes way down. A friend of mine built one of Wright tracks SRR transfer cabooses, and he didn't prime the flat car that held the cabin. It was cast in black resin, or it could have been a plastic body. The cabin was molded in grey resin.

The point is, he didn't prime these two different colored parts and the red on the flat car part is a much darker shade of red than the cabin. Here's what I mean. These two shots of the same caboose, and the color difference is very apparent.
XC7873A.png


XC7873.png


This same color difference almost cost him a merit award at an NMRA contest. This color difference is why I prime everything.
 
You don't HAVE to prime a lot of the time, but for every "don't need to" there will be 2 or 3 "do need to". Certain surfaces don't hold paint well, different colored surfaces will take paint differently (as Carey showed above) as will different different materials.......after a while you learn all that, but if you always prime, you'll ALWAYS be safe. The primer equals everything out.
 
My plan was to use scale coat II black and white on a plastic sd80 Mac shell for Norfolk southern. I ask because the detail door panels impressions are not that bold compared to sd70ace etc. I'm nervous because too many layers of paints on a kato may come out sloppy
 
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HurricanesFEC said:
I don't have an air brush and plan use a spray can. Who has the best primer for plastic ?
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Ive been using the dollar spray primer from wally world. Its been working well for me. Its not as thick as I imagined it being. The details look great after one coat and thats all Ive really needed. The car Im painting was orange and it will end up being silver.
 
If I learned anything from the first transfer caboose,was to always use a neutral primer coat,such as Floquil's Foundation. The reason is as I learned the hard way,is that the paint no matter what color will look much better,than if you didn't prime at all. Basically I believe you will use less paint,and get a better result. William.
 
IF you want the "best" primer, get yourself a can of Tamiya Fine Surface Primer. Yes, it is expensive, but, like anything else, you get what you pay for. I use the one in the rattle can, and it covers extremely well. One (maybe two) coats over black and the surface is pure white with very little fill. Adhesion properties are the best I've found, which is very important when doing brass.


Mark.
 
Mark R. said:
IF you want the "best" primer, get yourself a can of Tamiya Fine Surface Primer. Yes, it is expensive, but, like anything else, you get what you pay for. I use the one in the rattle can, and it covers extremely well. One (maybe two) coats over black and the surface is pure white with very little fill. Adhesion properties are the best I've found, which is very important when doing brass.


Mark.
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Thanks Mark
 
Could someone tell me why the hobby paint producers don't make flat colored paint? Flat paint is not that much different than primer.

If you used a flat black, there would be no need for primer.

The more glossy the paint, the thicker it usually is, and the more likely it will hide the details. Not to mention, most modelers choose to then apply dullcoat over the gloss paint. If you prime, spray with glossy paint, then dull coat, that's three coats of paint on the model where you'd only have one coat if you just used flat black paint.

You can brush on a thin coat of testors gloss where the decals will set, since they need a glossy surface, then hit the area with dullcoat afterwards.

I use Krylon flat paint since I think it flows out of the can thinner than even the hobby paints.

And if I miss any crevasses when spraying, usually around the stairs near the cab, I just leave it and follow up with a small brush later. Holding a can in a single spot trying to reach a hard to reach place is asking for a lot of paint build up in the surrounding areas.
 
I have been painting Brass steam and lately, some plastic steam. I always use Scalecoat II on plastic and Scalecoat I on brass.

FOR METAL - I strip the nasty cheap lacquer off the tender bodies, boilers etc and wash the parts in lacquer thinner (metal only!) The first coat is a thin 70:30 mix of paint and Scalecoat thinner. After a 4-6 minute wait I go back with a 40:60 mix of Paint to thinner. This will leave a glossy coat, without the extra detail obscuring primer coat under it. The parts are put in an old glass aquarium with flood lights over them to dry for 2-3 days. Until you don't smell any thinner.

For Plastic, it works the same but a longer wait for the parts to dry as you don't want to risk warping the plastic parts by using heat. Decals adhere better on the glossy surface. Seal your work with clear lacquer of whatever finish you want. I start with the engine as right out from the paint shop. I weather the sand, and soot and detail weather the appliances. Lastly I add real coal over the cast load.
 
Y3a;

For brass, instead of using the lamps, I've always used my wife's oven set at its lowest temp, 150-175` to literally bake the paint on. The heat does several things. One it cures the paint in a matter of minutes. Two, it hardens the paint to the point of almost making it impossible to damage or remove. Three, the heat actually brings out the gloss of the paint even better. I've painted brass where for some reason or the other, the natural gloss of the Scalecoat 1 wouldn't be evident. But after 45 minutes in a 175` oven, the model was so shiny, it looked totally wet.

But you do have to be careful when baking brass. I had one loco, that I painted about 30 years ago, in an oven whose lowest temp was 150`, start shedding parts. This was an early Korean import, and the solder used apparently wasn't any good, or poorly applied. A couple of hours with a soldering iron and some decent solder took care of that, and I was able to salvage the paint job as well.

EDIT: Another thing I forgot to mention, the heat also smooths out the paint. If you use a brush to paint things like feed-water heaters etc, that needed to be a different color from its surroundings, the heat actually "took away" any brush marks on the detail.
 
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Doughless said:
You can brush on a thin coat of testors gloss where the decals will set, since they need a glossy surface, then hit the area with dullcoat afterwards.

QUOTE]

The problem with that method, is that you will end up seeing where you applied the gloss even after you dull coat the entire thing. If you paint the shell with flat black, then brush on some gloss just where the decals are to go, that area will appear blacker than the rest. An overall coat of dull coat will never even this out - you will see a variation in the finish where you've dull coated over the flat finish and the gloss finish - it will never end up being the same.


Mark.
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I'm using an airbrush, so the Floquil's is a good primer? Really looking for something already at the right consistency for the airbrush

Matthew
 
Floquil has an excellent pale gray primer in the metal "shake" cans that you can spray without using an airbrush. Yes, I know it's not as economical as buying the bottles of primer and airbrushing them -- but the "shake" cans are great for those of us who want to get it done now, and have short attention

SQUIRREL!

:D

Regards,
Tom Stockton
 
When I do any painting I always prime. It give you a chance to check any work that has been done. plus, while some paints may effect the plastic but I have not had any problems when I primed.

Tim
 
I haven't painted in a while. I used to brush on a Floquil product that was supposed to seal(Sealcoat?) the plastic, so it wouldn't craze when you applied the actual paint. Last time I used this product, I noticed that it would thicken up substantially between uses, even with the 'Sealcoat Thinner,' that Floquil made, mixed in to the point of mostly being thinner, perhaps to address this problem. When I used the same product the first times prior to airbrushing, the product didn't thinken, even sitting in the jar, for maybe a year between uses. I bought several jars of the stuff over time, and had this problem with the product later on. I generally haven't manhandled the lids of my paints that much, to damage the caps, or sealing spacers.

Is 'Sealcoat' still around/recommended? Based on my later experiences, I went to priming with thin coats instead, as the sealcoat was worse than a heavy douse of paint, in terms of obsuring fine molded on details. It got so bad, I didn't even consider trying to airbrush the sealcoat onto the models for painting, as the stuff wouldn't flow.
 
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