Duplicolor primers too hot for current-production kits?

[Ace-Garageguy]

I swapped out the libtard nozzle/cap with Tamiyas, waaayyy better!

[charlie8575]

I don't like Plasti-Kote's new nozzle/cap thing, but I haven't had any issues with them dying with a full can as of yet.

How do you change the caps on those? I can't figure out how to get it apart.

And no, I've had no trouble with Plasti-Kote in the newer cans.

Charlie Larkin

[smacky-t]

 I normally use the Duplicolor primers with no problems.  I guess I have mostly old plastic models.  However I was wanting to know the difference between shellac and other paints?  Can shellac be used in place of a clear coat?

[Kit Basher]

  Can shellac be used in place of a clear coat?

The short answer is "NO". The clearest shellac still has a slight amber color. Even after it dries, it can be dissolved with alcohol, and it is prone to water spots. It is also softer than lacquers or enamel, so scratches easier.

Shellac is a resin dissolved in alcohol. Unlike many paints, it does not "cure" (change its chemical structure) as it dries. It is an excellent finish for furniture and musical instruments, because it can be easily repaired, but I would not use it on a model car.

[aurfalien]

Hi,

Well not to chime in as I know so little.  But in my experience Pledge Floor Care Finish works wonderfully as a barrier and can be removed via Ammonia (like Windex).

Alcohol or lacquer thinner seems to have no effect on it.

 

 

Edited October 11, 2016 by aurfalien

[Art Anderson]

The last few kits I've tested Duplicolor sandable primers on have crazed instantly...even if I shot the stuff slightly dry...just wet enough to avoid orange peel.

Has anyone else noticed this?

I'm not really wanting to have to switch to model-specific primers, but will if it's absolutely necessary.

Bill, not in my book!   I'm using Dublicolor Primer (the very same stuff you use) all the time, on new kits, older kits, even ancient ones. and given that I always airbrush both primers and finish colors, I have virtually NO problem with any "crazing" beyond a very light, fine "frosting" effect with my very first pass of the airbrush.  50 years ago or so, I "coined" my own term for this--"shock-proofing" the plastic surface".  I came to that conclusion simply because on subsequent passes with my airbrush, not only was (nor is there still!) any further crazing of the plastic surface, either with successive coats of primer, nor with any lacquer finish colors I have ever used.

The key to my success is (and I believe I have explained this a couple of times before) that I always use rattle can lacquer primer (Duplicolor has been my favorite for decades!), decanted into my airbrush jar, and then adding a bit more lacquer thinner (I use the really "high-tech" KleenStrip stuff--nothing exotic).  Well thinned out, Duplicolor's red oxide primer, airbrushed on in very fast passes, seems to work by allowing only minute penetration of the lacquer thinner into the plastic surface, and seemingly (for me at least!) "shockproofs" the surface so that succeeding passes with my airbrush just do not further affect the outcome at all negatively.

Once the primer is dry, and I've checked the body shell over for any imperfections, and corrected those by whatever filler I seem to think will do the job, and having sanded those areas out smooth--I simply repeat the process, by spot-priming--again with little if any truly visible crazing.

My next step with the primer is to actually polish it, using 8,000-grit Micromesh cloth, generously wet, to actually bring the primer to a dull shine (Oh I know, HERESY!). and then washing the body down with ordinary Dial hand soap (I'm glad I use DIAL, wish everybody did!).  rinse, pat dry with a piece of clean 100% cotton tee-shirt knit, blow any lint off the body surfaces with compressed air, and paint the danged thing with either lacquer or enamel (I thin my enamel paints for airbrushing with that same Walmart-sourced Kleen Strip Lacquer thinner (again, the HERETIC in my is sticking out all over!), which works just fine.

My secret is really NO SECRET here:  For starters, I have used nothing but external mix airbrushes since my first Binks Wren, purchased in December 1961 (been using a Paasche H #3 for the past now 30 years or so).  Second, I thin alll paints, lacquers and enamels, to the consistency of 2% milk--observing that consistency by seeing how the thinned paint "sheets down" the sides of my glass color jars as a final check.  That "sheeting" effect should approximate the sheeting action of 2% milk down the insides of a glass of the stuff, as you drink it!).  Next, I use very low pressure to the airbrush--I worked this out years ago, after I had a very square body shell turn out with a finish at the rear that looked as if it had been painted in a SANDSTORM.   Analyzing that failure, I noted that with full air pressure from my diaphragm compressor, overspray toward the rear end of the body sides, tended to swirl around, landing on the rear surfaces about half-dry--it didn't flow out, just sat there like so many 1/25 scale grains of sand.  Reduce the air pressure (and I do not use a pressure gauge--I simply bleed air off at the moisture trap, to the point were the paint just srpays out of the airbrush, but yet is very soft in velocity--the thinning out I described above facilitates that very nicely!

The third leg of this milking stool, is "Close".  I do my airbrush paintjobs with my Paasche H #3 no more than 3/4" to a full inch from the model surface.  This gives me a spray fan at the model surface that is no more than a half inch wide--almost a 1/25 scale professional spray gun pattern!    i also move the airbrush over the surfaces only moderately fast, just fast enough to avoid any puddling, or runs, but slow enough so that even the first pass results in a smooth, if semi-gloss sheen--succeeding passes like this will result in full color coverage with only minimal polishing required for a very high shine.  In the bargain, by doing it this way, I can keep raised detail, such as chrome body trim and badges/scripts standing out prominently, not drowned beneath a really thick coat of paint.

This entire process is what I have come to call "TSC"  (Thin, Soft and Close).  It's worked for me since the middle 1960's and virtually never do I have a failed paintjob due to crazing, or er even runs or sags--generaally I can completely skip the range of Micromesh polishing cloths, and go straight to using their liquid polishing compound and a piece of 100% pure cotton tee-shirt knit.

Art.

[Art Anderson]

 I normally use the Duplicolor primers with no problems.  I guess I have mostly old plastic models.  However I was wanting to know the difference between shellac and other paints?  Can shellac be used in place of a clear coat?

Shellac traditionally uses Methyl Acohol (methanol) as it's reducer, and methanol is almost death on styrene., not to mention almost all commonly used enamels and lacquers--it's the active ingredient of most paint/vanish strippers (that are not to be used on non-ferrous metals such as aluminum).

Art

[Ace-Garageguy]

Bill, not in my book!   I'm using Dublicolor Primer (the very same stuff you use) all the time, on new kits, older kits, even ancient ones. and given that I always airbrush both primers and finish colors, I have virtually NO problem with any "crazing" beyond a very light, fine "frosting" effect with my very first pass of the airbrush.  50 years ago or so, I "coined" my own term for this--"shock-proofing" the plastic surface".  I came to that conclusion simply because on subsequent passes with my airbrush, not only was (nor is there still!) any further crazing of the plastic surface, either with successive coats of primer, nor with any lacquer finish colors I have ever used...etc.

 

Art, thanks for taking the time to re-explain your process. I've got a good airbrush now, know how to use it, but have simply put it off because I used to be able to turn out consistently fine paint jobs using rattlecans...something I've offered advice on at length in the past as well.

Things have changed somewhat, obviously, because my tried-and-true rattlecan methods no longer work acceptably well.

Time to adopt your techniques, I guess. And again, thanks for posting so much detail. I ought to be able to make it work. 

[Art Anderson]

Art, thanks for taking the time to re-explain your process. I've got a good airbrush now, know how to use it, but have simply put it off because I used to be able to turn out consistently fine paint jobs using rattlecans...something I've offered advice on at length in the past as well.

Things have changed somewhat, obviously, because my tried-and-true rattlecan methods no longer work acceptably well.

Time to adopt your techniques, I guess. And again, thanks for posting so much detail. I ought to be able to make it work. 

Bill, in retrospect, although I don't recall seriously thinking of it--in a way, the technique I've been using all these years is pretty much a matter of treating a pant job as if I were doing it with a spray gun that was at least close to 1/25 scale!   It does give maximum color coverage with minimal paint thickness, and with practice, this method allows me to get away with relatively little in the way of polishing.

Art

[martinfan5]

Art, thanks for taking the time to re-explain your process. I've got a good airbrush now, know how to use it, but have simply put it off because I used to be able to turn out consistently fine paint jobs using rattlecans...something I've offered advice on at length in the past as well.

Things have changed somewhat, obviously, because my tried-and-true rattlecan methods no longer work acceptably well.

Time to adopt your techniques, I guess. And again, thanks for posting so much detail. I ought to be able to make it work. 

Like they say, you are never to old to learn new tricks

You can always add some plastic safe thinner to the decanted primer , which will help a bit in neutralizing it. 

 

[kitbash1]

I haven't had any issues with Duplicolor (yet).

Same here. It's been my go to primer for a long time.

[Dave Van]

Dupli-color sealer has never given me any issues on any brand model cars or my model trains. 

[oldcarfan]

I just primed three kits today, two of Revell's Porsche 911 with the hard white plastic and another kit that is of AMTs softer gray plastic. Both of the Revell's crazed. Not super bad, but it took a good bit of sanding to get the finish ready to take paint. I've noticed that is the case in a lot of my kits with that harder white plastic.

[Dave Van]

I just primed three kits today, two of Revell's Porsche 911 with the hard white plastic and another kit that is of AMTs softer gray plastic. Both of the Revell's crazed. Not super bad, but it took a good bit of sanding to get the finish ready to take paint. I've noticed that is the case in a lot of my kits with that harder white plastic.

With what primer???  I think there is a difference between primer and the primer-sealer #1699.  

[Ace-Garageguy]

With what primer???  I think there is a difference between primer and the primer-sealer #1699.  

There IS a difference between primer and primer-sealer.

Sealer, at least in the big-car world, is usually a non-sanding product.

Sanding usually defeats the whole purpose of a sealer by compromising its effectiveness as a barrier.

I should have been more specific in the opening post.

It's all the sanding and "scratch-filler" or "high-build" primers (also sanding-type, obviously) that are crazing everything new.

Because of the way I work in particular, with a lot of relatively heavy modifications, it's imperative that I use a "sanding" or "filling" type of product most of the time.

[Dave Van]

I use the sealer #1699 for most of my work.....and I use it as a 'scale' primer.......I do sand it.  There is no one correct way....what works for me may not work for others.  I just share what works for me......it or a  variation of my way may work for others.  thx

[oldcarfan]

With what primer???  I think there is a difference between primer and the primer-sealer #1699.  

Forgot to mention it, sorry. Dupli-Color sandable Hot Rod Primer in the spray can. This and their gray filler primer are my go-to primers. It wasn't horrible, it looked like a bad case of orange peel. I was able to wet sand it smooth then put a couple of very light coats on it and it was okay. More annoying than anything.

[Mike_G]

I don't shoot a wet coat with anything hot until I've built up a sort of "barrier layer" of several light mist coats and let them dry

[slusher]

There IS a difference between primer and primer-sealer.

Sealer, at least in the big-car world, is usually a non-sanding product.

Sanding usually defeats the whole purpose of a sealer by compromising its effectiveness as a barrier.

I should have been more specific in the opening post.

It's all the sanding and "scratch-filler" or "high-build" primers (also sanding-type, obviously) that are crazing everything new.

Because of the way I work in particular, with a lot of relatively heavy modifications, it's imperative that I use a "sanding" or "filling" type of product most of the time.

Curious, why not just switch to a plastic safe primer like Tamiya and have no worries? Easy to find at HL and get 40 percent off per can.

[Ace-Garageguy]

Curious, why not just switch to a plastic safe primer like Tamiya and have no worries? Easy to find at HL and get 40 percent off per can.

That's partly what I'm having to do, but I'm frankly chapped that my go-to primers for MANY years, and that are very good at what they do AND very cost effective, no longer work. I rather resent being forced to change my materials of choice and procedures that have worked well for me up til now, simply so the kit manufacturers can save a few pennies per kit by using cheaper, less solvent-resistant styrene blends.

Progress again.

Very often, "new and better" isn't better at all.

The procedures offered up by Art Anderson and Steve Guthmiller will obviously produce the kind of results I'm looking for (the photos of their work certainly prove that) but some of the other suggested procedures simply won't. Shooting "mist" coats from the can will only make orange peel, and sanding it out will only succeed in obliterating fine detail.

These were not issues for me before, as it was possible for ME to shoot a slick, wet coat of primer with no orange peel AND no crazing. No so any more.

Edited October 19, 2016 by Ace-Garageguy

[Muncie]

I don't shoot a wet coat with anything hot until I've built up a sort of "barrier layer" of several light mist coats and let them dry

Mike, 

I'm with you on that - paint or primer - a couple of light coats, let them get tacky and gradually apply wetter coats so the paint smooths out.

Even with my favorite Plasti-Kote T-235 sandable gray primer and older kits plastic, I could get light crazing if the first coats were too wet. Plasti-Kote has a lot of texture so I want to try some Duplicolor primer-sealer but will take it slow.  There are a couple of kits that will make donations to the learning experience.

Edited October 19, 2016 by Muncie

[High octane]

Curious, why not just switch to a plastic safe primer like Tamiya and have no worries? Easy to find at HL and get 40 percent off per can.

That's what I do as I've been using Tamiya primer for a few years now and very happy with the results. I do like the idea of 40% off also.

[Art Anderson]

Like they say, you are never to old to learn new tricks

You can always add some plastic safe thinner to the decanted primer , which will help a bit in neutralizing it. 

 

Bill, and everyone else:   I guess I should add a bit of my rationale here, in addition to having explained my concept of "TSC" as posted above in this thread!   In short, I shoot (no pun intended!) for "maximum coverage with minimal paint"--essential, or so it seems to me, when dealing with painting in 1/25 scale, for realistic finishes.  I'm not going for "Best Paint" awards, hence my distaste" for that "dipped in syrum" look.   Now, if you think of it, a rattle can nozzle (be it on a can meant for painting on 1:1 car surfaces, or on a 1/25 scale model car body--is about as delicate as trying to paint a real car body with a freakin' firehose!  That's what got me into airbrusing in the first place, WAY back in January1962!   While of course, at that time, I was more worried about getting nice paint jobs with the likes of Pactra "Soft-Spray" hobby enamels, the same principal applies even more when using automotive lacquers.  Sure, there will be minute crazing even with an airbrush--but that's much more like very fine "frosting" of the surface with the first pass or so, than serious crazing which can rival the skin of a 120-yr old man with a serious skin disease (OK, so I exaggerate a bit here!).  SERIOUSLY, the only time I have ever had to deal with that sort of crazing with Duplicolor or other lacquer primer on styrene, was when I painted a Gunze-Sangyo BMW Isetta body that was molded ENTIRELY in clear styrene (which is by its nature, the purest form of styrene of polystyrene there is.  Here is the final result, once I figured out how to proceed--perhaps the proof that my TSC philosophy does work for me, first time, EVERY TIME:  Please note that this pic was shot in 2003, with my first (and very primitive) digital camera--but if you really look closely, you will not see any crazing in that surface!  It's all a matter of stopping, thinking, and figuring out how to use so-called "Hot Lacquers" on "craze-sensitive" styrene surfaces.  I think this model speaks for itself as to how possible it is to use even the hottest lacquers on even pure styrene.

Art

[JTalmage]

I use Tamiya's grey primer, and they're fine primer in grey and white. I've used it on new and old plastic.... no problems.

[martinfan5]

Curious, why not just switch to a plastic safe primer like Tamiya and have no worries? Easy to find at HL and get 40 percent off per can.

I enjoy not having any worries when it comes to primer.