What went wrong? Painting question

[Dr. Bob]

Hi there,

I recently painted a body, which turned out pretty bad. It looks very grainy and not smooth at all. I shaked the can 5 minutes, put on primer and 2 mistcoats before I put on 2 wet coats. What went wrong here?
I attached 2 pics for reference.




thanks

[robrex]

It looks to me that either the paint or the primer etched the surface of the plastic. That can happen when you use a 'hot' primer or paint like automotive stores sell. What kind did you use?

[Dr. Bob]

I used a spraycan from a paintstore, brand was dupli-color. Should be suitable for plastics. It wasn't expensive so I hoped it would be a nice alternative for Tamiya spraycans since they do not offer a lot of colorshades.

[356speedster]

I had a similar result last weekend, very irritating, since I ususally have no problamens to get smooth topcoats. But I think the result was a combination of two incidents.

1. I heated the cans too much (about 40 degrees celcius)
2. I sprayed too far away from the body.


The rusult is that the paint dryies before it hits the body, and the paint gets as rough as sandpaper.

I've now spent hours, sanding and cutting the paint, and it is decent now, but its difficult to sand it nice and level without going through too the primer, especially on the edges. So I'm preparing to strip it and give it new shot.

[robrex]

If it laid down well out of the can then went like this after a while, I would say the paint has reacted with the primer then. You used Dupli-color paint, what primer did you use?

[Dr. Bob]

I used Tamiya primer. I don't really know if it reacted with the primer or if the painting process went wrong, since I do not have a lot of experience with spraycans. What is the best way to strip it? And what automotive paint cans are suitable for these models? I think automotive paints have more shades to pick from. Or do they only sell paints for airbrushes?

[356speedster]

It could be that the Dupli-color reacted to the Tamiya Primer.

I just finished stripping my car now. Placed it in an plastic container and filled it up with 99% rubbing alcohol, waited 10 minutes and started to scrub it down with a stiff kitchen brush. 10 minutes later I finished scrubbing with a toothbrush to reach all the small openings.

Not sure if Alcohol will strip Dupli-Color but its woth a try. Just remeber to wear rubber/plastic gloves and VERY IMPORTANT: eye protection.

[ZoomZoomMX-5]

Your pics are not clear enough to know if it was just bad paint, or if the paint damaged either the primer or plastic.

It looks like rough primer covered by color (I like to wetsand primer as smooth as possible before applying color). But if you used Tamiya primer I'd say it looks like your auto paint isn't very good; and that may be just a bad can of paint. I've used Duplicolor spray cans before and found them a bit much for plastic models. It's strong paint, and can etch plastic. It's better to airbrush these types of paints so you don't lay on so much at one time, by applying thin coats to more slowly build up the color.

[primera man]

Wet coats to heavy coming out of these cans compared to air flow from can. The paint comes out to thick and 'blob's" onto the model

[POPSICLE_PETE]

I have been having the same problem, and I think it might be becuase the primer looks smooth because of the dull finish but really isnt.

[bobss396]

Always keep the primer and paint within the same brand, Duplicolor makes a great primer too. I don't think that you have a paint/primer reaction though. It looks like the paint just has too much orange peel.

I'm not a huge believer in "mist" coats, those tend to lead you down the path to a grainy finish. On the first pass, I try to cover those hard to reach areas, edges, fenderwells for example. Duplicolor flashes over quickly and you can shoot another coat within 20 minutes.

I think that you didn't lay the paint on heavy enough. I warm up my paint cans in a pyrex measuring cup with hot tap water, I check it and make sure it doesn't go over 105 F. Give it 5-10 minutes to warm up.

Since your orange peel is so severe, you may want to strip it with either Castrol Super Clean, oven cleaner or Easy Lift Off (aka ELO found in hobby shops).

Bob

[NOMADGAMER]

Don't mix paints unless you have to, If you lay a Duplicolor Primer, lay a Duplicolor Wetcoat, etc.

FWIW, I love Krylon primer, good-n-cheap.

[bobss396]

Originally Posted by NOMADGAMER

Don't mix paints unless you have to, If you lay a Duplicolor Primer, lay a Duplicolor Wetcoat, etc.

FWIW, I love Krylon primer, good-n-cheap.

I used to be big on Krylon, but have had a few problems with it crazing and not drying that qyuckly. I have a heavy hand with any paint and it doesn't tolerate that for me. But name your poison, whatever works for you is great.

Bob

[tigeraid]

For what it's worth, I use Dupli-color primer ONLY and that's with any paint, and have never had problems, including Tamiya.

I'm not going to try and dump on anyone else's opinions here, but what you have there is clearly orange peel. There's a few things that can cause it, but a lot of the time it's severe humidity, so try painting somewhere else in your place that might be dryer, even if that's outside, for a brief period.

The other major reason for orange peel is not allowing enough drying time during coats, so the paint cant flash harden before you put the next coat down. That can be true of primer not given enough time to dry either, btw. This goes for mist coats or heavy coats. Also make sure that when you're drying the coats, don't use a fan or put the car near a heating vent, or anything else that "blows" over it.

That's about all I can offer up. All my examples of orange peel have happened because of improper drying time between coats. Just my two cents.

[Some_Kid]

In my opinion it looks like you didnt spray close enough to the body. I would resomend using duplicolor clear with your paint as well as that seems to leave a smoother and more glossy finish. Your problem could also be due to the fact that you sprayed outside(did you?), from my experience duplicolor is very sensitive to humidity and temperature. Often times if i spray with it outside the paint will slowly but surely start to fog and you can see a rainbow color appear.Ive used tamiya with duplicolor before and they seem fine together, but duplicolor primer is thicker and tends to " fill " a little bit.