Spraying Tamiya TS rattle can paint on bare plastic ?

[Goodwrench3]

Hi all:

I have what is probably a dumb question, but if ya don't ask...

I'm completing a NASCAR chassis/roll cage assembly now.  I usually paint this an entire assembly.   What I'm wondering is -- do I need to put on a coat of primer first ?   Or what about the idea of spraying the Tamiya  color directly on the bare plastic ?   I'm kinda new to the Tamiya spray lacquers (vs. enamels).  Looking for guidance.  I've been reading a lot of posts where it seems some always put a primer coat under the Tamiya spray paints.  I'd be using Tamiya gray spray primer if any.

Thanks for the patience.

 

 

[stitchdup]

I've used it on bare plastic with no problems but it probably wouldn't hold up to polishing. I've used it with primer (duplicolour) too again with no problem. I would test it on some scrap first though as some of them are a little more opaqe than others.

[Goodwrench3]

36 minutes ago, stitchdup said:

I've used it on bare plastic with no problems but it probably wouldn't hold up to polishing. I've used it with primer (duplicolour) too again with no problem. I would test it on some scrap first though as some of them are a little more opaqe than others.

Yeah I've sprayed some like sem-gloss black on parts without primer -- no problem.   I guess there's always the risk of if pulling away from corners, etc. if it doesn't have the primer coat to "bite" to.

Better safe than sorry --  I'll put on a coat of Tamiya primer first.

Thanks for the reply.

[Rodent]

I have used it over bare plastic numerous times with no adhesion issues. In fact, it is just the opposite. I have yet to find the magic cocktail that will do much of a job of removing Tamiya from bare styrene. Yes I have tried all the usual and unusual suspects.

[64Comet404]

When I use Tamiya lacquer for painting roll cages, I prefer to prime the parts (so I can see the parting lines I missed), and then shoot with the final colour coats.

[Goodwrench3]

8 minutes ago, 64Comet404 said:

When I use Tamiya lacquer for painting roll cages, I prefer to prime the parts (so I can see the parting lines I missed), and then shoot with the final colour coats.

Thanks.   The only thing I noticed was on a car I did this with last year,  the color coat wasn't real "smooth" obviously because I wasn't able to sand the primer coat on the roll cage/chassis.  The finish was "grainy" in some areas.   Not a big deal.  It's a roll cage/chassis -- not a show car.

[64Comet404]

The easiest way I have found to get rid of the 'graininess' is to scrub the part with a toothbrush and regular toothpaste, rinse, wash with dish soap, dry, and shoot your colour coats. Takes the rough surface away, but leaves enough 'tooth' for the paint to grip. Hope this helps!

 

[gman]

There used to be a local hobby shop near where I started work years ago- the owner had a number of his automotive builds on display, and he was very fond of using Tamiya lacquers exclusively for all of his finishes. I had tried Tamiya and failed years before. In speaking with him and picking out some paint, he was emphatic that he never used primer, just shot the Tamiya over bare styrene. He never used clear over his finishes either- just polish. He got some outstanding finishes. Based on his enthusiasm, I tried Tamiya lacquers again using his bare plastic technique, and guess what- I had some more paint disasters.

Now that I've had better luck with Tamiya lacquers, I do use primer, and I do use clear (most of the time),  but he was living proof that it isn't necessary. Sadly, that hobby shop has long closed, but what it boils down to is experimenting with a product like Tamiya lacquer, and coming up with a technique and system that gives consistent results...for you. The biggest pro of not using primer or clears is a thin finish that doesn't obscure surface detail. He mostly built Japanese kits (Tamiya, Hasegawa), whereas I usually build kits that require some more prep than those, plus some added customization. Primer allows for getting a more uniform surface over that bodywork to get an even finish once the color coats are applied, and paint thickness is not such a concern.

[Goodwrench3]

That's interesting.   I've actually heard some refer to Tamiya TS spray paint as "idiot proof".   LOL.

I've also seen YouTube videos of guys spraying bodies using Tamiya rattle cans with no primer -- and the finish is beautiful.  No clear coat needed.   They make it look soooo simple.

I rarely never need to do any sanding on a body -- there almost always are sharp edges or mold lines that have to be removed.   I guess if you go to fine enough sand paper you wouldn't need primer then (i.e. no filler is on the body).   But the other case for primer is to adjust the tone of the color coat -- i.e.  darken it a bit with gray primer for example.

Which clear are you using over the Tamiya paint ?   That seems to be another big debate.

 

 

[gman]

5 minutes ago, Goodwrench3 said:

That's interesting.   I've actually heard some refer to Tamiya TS spray paint as "idiot proof".   LOL.

I've also seen YouTube videos of guys spraying bodies using Tamiya rattle cans with no primer -- and the finish is beautiful.  No clear coat needed.   They make it look soooo simple.

I rarely never need to do any sanding on a body -- there almost always are sharp edges or mold lines that have to be removed.   I guess if you go to fine enough sand paper you wouldn't need primer then (i.e. no filler is on the body).   But the other case for primer is to adjust the tone of the color coat -- i.e.  darken it a bit with gray primer for example.

Which clear are you using over the Tamiya paint ?   That seems to be another big debate.

 

 

I suppose if you find a big enough idiot, all sorts of things are possible ?

Where I went wrong in my early experiments was putting too much paint down, too fast. I had techniques that worked out well for enamels (which I used for decades with varying degrees of success), and the biggest part of my problem with the Tamiya lacquer was not adjusting the techniques, and not understanding how the grain/texture you get in mist coats is not a huge problem when you apply the color coats, as the way the lacquer cures tends to level that out.

I have used Tamiya TS clear, Testors Wet Look clear, even the older lines of Testors enamel and lacquer clears. I am wanting to try the catalyzed 2K clears. If a solvent is "cooler" than that used in the base coat, you can generally use it over top of the Tamiya lacquer. As always, experimentation is key, and a spoon test or a scrap body comes in really handy to avoid having your lovingly prepared model become a science project. Another trend I have yet to try is cutting Tamiya's aqueous acrylic clear with their lacquer thinner and airbrushing that. When I get to that, I'll try it on scrap bodies before committing to it on one that has been carefully painted.

[gman]

16 hours ago, 64Comet404 said:

The easiest way I have found to get rid of the 'graininess' is to scrub the part with a toothbrush and regular toothpaste, rinse, wash with dish soap, dry, and shoot your colour coats. Takes the rough surface away, but leaves enough 'tooth' for the paint to grip. Hope this helps!

 

Comet powdered cleanser on a toothbrush under running water is another good way to level primer and color coats- more aggressive than toothpaste, should you need to cut texture faster. Agreed on the dish soap- a "must" to prevent problems in subsequent coats of paint. I have used the toothpaste technique as well, when mild smoothing is required.

[Goodwrench3]

2 hours ago, gman said:

I suppose if you find a big enough idiot, all sorts of things are possible ?

Where I went wrong in my early experiments was putting too much paint down, too fast. I had techniques that worked out well for enamels (which I used for decades with varying degrees of success), and the biggest part of my problem with the Tamiya lacquer was not adjusting the techniques, and not understanding how the grain/texture you get in mist coats is not a huge problem when you apply the color coats, as the way the lacquer cures tends to level that out.

I have used Tamiya TS clear, Testors Wet Look clear, even the older lines of Testors enamel and lacquer clears. I am wanting to try the catalyzed 2K clears. If a solvent is "cooler" than that used in the base coat, you can generally use it over top of the Tamiya lacquer. As always, experimentation is key, and a spoon test or a scrap body comes in really handy to avoid having your lovingly prepared model become a science project. Another trend I have yet to try is cutting Tamiya's aqueous acrylic clear with their lacquer thinner and airbrushing that. When I get to that, I'll try it on scrap bodies before committing to it on one that has been carefully painted.

In your experience, which of the rattle can clears tend to level the best  ?

That last time I used a clear from a rattle can was back in the early 1990's.  It was a Testors clear (can't remember which) that I sprayed over Testors enamel spray paint.  I sprayed one coat and it leveled itself perfectly.  No sanding, polishing, etc. needed.  It was great.

 

[gman]

If you are spraying over Tamiya lacquer, I'd lean towards Tamiya's lacquer clear. Dust on the first few coats, making sure your base coat is very, very dry and cured, as it can cause metallic finishes to wash or mottle. I've also had good results shooting their clear immediately over freshly painted lacquer that hasn't completely dried, so both color and clear coats gas out together. You can build it up in multiple coats for best results- it is a thin clear coat. You can now buy the same product unreduced in bottles from Tamiya should you prefer to airbrush, and use Tamiya's lacquer thinner with retarder, or Mr. Color's equivalent thinner.

Testors Wet Look (now called Extreme) is a great product when it works, but it goes on relatively thick and can have some orange peel if you aren't careful.  I've had a few cans dry with bubbles in the clear coat after curing. I experimented with spraying distance, wetness of coat etc. and found some cans do this while others don't.  If you get a good can, it is beautiful stuff, dries hard and polishes nicely. Quality control seems to have pooped the bed at Testors now that they are discontinuing a lot of products likely to be used by serious adult modellers.

With either option, experiment on scrap bodies or plastic spoons. If airbrushing, the 2K clears are very promising, but you want to keep this stuff off your skin and use a respirator. You'll find a bunch of other suggestions searching threads on the forum with the keywords "clear coat."

[espo]

I'm in the primer first camp myself. To my mind primer serves in many was to create a better final paint finish. You can sand bare plastic to your hearts content but with out a dusting of primer and another light sanding your not going to know if you really have a smooth surface. You can do this with the final color also but I think you will usually find that the primer is thinner and doesn't tend to cover trim details and body panel lines as much. With the roll bars on a kit what can happen is that the meeting points between different parts of the roll bar might get either to much paint or not enough. Should a joint between two or more parts have a very fine gap it may show up in the final color coat where if primer had been used and light sanding would even out the joint and often the primer offers just enough "filling" to hide the joint. The color of primer used can effect how the final color looks. Remember your sanding away most of the primer anyway and it is easier to sand than most color coats and the smoother you can get your primer the better chance of your color coat turning out the same way. You can do it either way, which ever works best for you. 

[gman]

I typically have a range of primers on hand, useful for different purposes. I love everything about Tamiya's Fine Surface Primers (except the price), usually have Duplicolor and Plasticote primers on hand, and have started experimenting with Badger's Stynylrez water bourne urethane primer as well- initial tests look promising. 

I usually spray a lot of lacquer in the rare instances I get some modelling time, and became accustomed to relying on primer as a barrier coat between lacquer and plastic. While Tamiya and Testors synthetic lacquer won't craze styrene and can theoretically be used over bare plastic, I do like the results better over a smooth primer surface.

[Rodent]

I should add that I always use primer on body parts, for all the reasons stated by others here. I generally spray frames, suspension parts, rear axles, etc. right over the bare plastic. Same with most interior parts unless seats have a seam that needs to be filled. I lived a little dangerously a while back and used Tamiya pink primer under auto parts store Chevy orange engine paint and was very happy how it turned out. Since most of my subject matter is American muscle and pony cars, floor pans get a coat of primer because it is part of the final finish. I don't see the need for using primer over white plastic when I am painting a control arm black or exhaust pipes steel though. It's whatever works for you.

[peteski]

Those TS spray lacquers are designed to be plastic compatible, so they can be applied to bare polystyrene.  They will adhere to it extremely wheel if the plastic was cleaned well. But that goes for any paint - no paint will adhere well is the plastic was not cleaned properly.

If the car body does not have any modifications and is prepped well, then I don't use primer. Only when some modifications were made, or putty used, then it makes sense to use primer first., to blend the dissimilar areas.

[martinfan5]

On 10/6/2020 at 4:16 PM, peteski said:

Those TS spray lacquers are designed to be plastic compatible, so they can be applied to bare polystyrene.  They will adhere to it extremely wheel if the plastic was cleaned well. But that goes for any paint - no paint will adhere well is the plastic was not cleaned properly.

 

This is not set in stone though , but TS sprays have been crazing recent Revell kits(review builds from very prominent builders) , being used over their primer , I had issues building a Fujmi kit using Tamiya primer and paint and it was causing issues to the plastic, mild crazing/hazing.

But normally you are right Peter, so its bit odd as to why its happening.

 

Edited October 8, 2020 by martinfan5

[peteski]

33 minutes ago, martinfan5 said:

This is not set in stone though , but TS sprays have been crazing recent Revell kits(review builds from very prominent builders) , being used over their primer , I had issues building a Fujmi kit using Tamiya primer and paint and it was causing issues to the plastic, mild crazing/hazing.

But normally you are right Peter, so its bit odd as to why its happening.

 

That is odd Jonathan, especially if this happens even over a a coat of primer!  I was not aware of that.  I guess the bottom line is to make sure check compatibility of any paint with the kit you are building.

[slusher]

On 10/5/2020 at 5:07 PM, Goodwrench3 said:

Yeah I've sprayed some like sem-gloss black on parts without primer -- no problem.   I guess there's always the risk of if pulling away from corners, etc. if it doesn't have the primer coat to "bite" to.

Better safe than sorry --  I'll put on a coat of Tamiya primer first.

Thanks for the reply.

Have you tried Krylon short cut flat black from Hobby Lobby. Spays well and is almost a semi gloss black without primer. It is an enamel. I have sprayed it over Tamiya primer. I primer everything but Krylon is safe without.

[martinfan5]

42 minutes ago, peteski said:

That is odd Jonathan, especially if this happens even over a a coat of primer!  I was not aware of that.  I guess the bottom line is to make sure check compatibility of any paint with the kit you are building.

I am wondering if something changed in the formula, it was a new can I got maybe 6 months ago.

[peteski]

1 hour ago, martinfan5 said:

I am wondering if something changed in the formula, it was a new can I got maybe 6 months ago.

That would be weird as the TS spray paints are specifically made for Tamiya's plastic model kits.  Maybe Tamiya uses higher quality ABS plastic?  But what really makes no sense to me is that it will craze plastic even with a primer base coat. After all we use primers as a barrier coat when using hot lacquers designed for 1:1 (metal) cars.

[Plowboy]

9 hours ago, martinfan5 said:

This is not set in stone though , but TS sprays have been crazing recent Revell kits(review builds from very prominent builders) , being used over their primer , I had issues building a Fujmi kit using Tamiya primer and paint and it was causing issues to the plastic, mild crazing/hazing.

But normally you are right Peter, so its bit odd as to why its happening.

 

Are you/they spraying straight from the can or decanting, thinning? If decanting/thinning, it could be the thinner.

Not too long ago, I had a bleed through issue using Tamiya primer and paint. It was the Lindberg '34 Ford pickup molded in yellow. Everything was fine until I sprayed the second coat of clear. Luckily, I had only done the hood and bed. I let them dry out, then sprayed one coat of color and one coat of clear. No bleed through. But, I didn't dare spray a second coat of clear!

I always primer every part. It makes a huge difference come time to paint. The paint covers better and won't try to wick away from sharp corners/irregular surfaces found on floorpans and engines. 

[Goodwrench3]

12 hours ago, slusher said:

Have you tried Krylon short cut flat black from Hobby Lobby. Spays well and is almost a semi gloss black without primer. It is an enamel. I have sprayed it over Tamiya primer. I primer everything but Krylon is safe without.

Thanks for the tip.  Might be a less expensive route for semi-gloss black parts (frames, chassis, etc.) than Tamiya TS semi-gloss black.  I'm guessing if it's Krylon it also dries really fast even though it's an enamel ?

 

[martinfan5]

8 hours ago, Plowboy said:

Are you/they spraying straight from the can or decanting, thinning? If decanting/thinning, it could be the thinner.

Not too long ago, I had a bleed through issue using Tamiya primer and paint. It was the Lindberg '34 Ford pickup molded in yellow. Everything was fine until I sprayed the second coat of clear. Luckily, I had only done the hood and bed. I let them dry out, then sprayed one coat of color and one coat of clear. No bleed through. But, I didn't dare spray a second coat of clear!

I always primer every part. It makes a huge difference come time to paint. The paint covers better and won't try to wick away from sharp corners/irregular surfaces found on floorpans and engines. 

Straight from the can, never had issues with Tamiya being to hot on Japanese plastic, so its a head scratcher