Enamel Paint thinner questions

[Bobster]

Good afternoon all,

I'm returning to building and air brushing soon.  I have a large amount of "later"(not the early "hot" thinner based) Floquil and Model Master enamel paints.  With the demise of Testors and Floquil what is available/recommended for airbrush thinner that won't melt my railroad (cars, engines, buildings), 1/25th auto's, 1/48th aircraft, and 1/35th armor models?

I will probably eventually go acrylic but I have an investment in enamel I don't want to throw out.

Your advice is greatly appreciated,
Bobster

[Doug G.]

I've always used regular mineral spirits.

Doug

[robert3985]

EDIT: It's been a loooong time since I have opened a bottle of Floquil Paint, so I am open to other opinions about it, particularly Peteski's @peteski information since he's studied it more than I have since his opinions and advice don't affect me because I won't be using any Floquil paints again...ever (except Pollyscale).  Out of respect for Peter's competency and on-hand experimentation and paint experience, I've made corrections in my main text.

Original "hot" Floquil paint (not Pollyscale) was, in my opinion, not "enamel based" as far as my usage of it went.  The thinner for it was called Diosol and it was known to eat plastic, which is why Floquil marketed a clear "Barrier" to spray on first that would protect the plastic surface.  So, this meant there was a Barrier coat, a flat color coat, a glossy coat for decaling, then a decal sealer coat on plastic models...FOUR coats of paint in order to apply it properly.

As far as I know, regular old paint thinner will not thin original Floquil paint, and lacquer thinner isn't ideal.

From what I've read, Xylol (or Xylene) is virtually identical to the original Diosol, and used to be available at The Home Depot or paint stores. Maybe it still is.

As far as Floquil Rev2 paint, I never used it, so I won't comment about it.

I never liked the original Floquil paints because the colors weren't anywhere near being correct for UP, and I don't like flat finishes for a few reasons.

For Testors Model Master Enamels, PAINT THINNER is what you want...not mineral spirits, not odorless mineral spirits, not odorless paint thinner, not lacquer thinner.

I use my collection of Testors Model Master Enamels (thinned with PAINT THINNER) for several things when painting engines and cars...or for brush painting small detail parts when necessary.

For weathering, I use mostly my collection of Pollyscale acrylic weathering colors, artist's oil paints, and Tamiya Panel Liner (an enamel).

I prefer to use Scalecoat II (enamel based) for UP engines and when I need to spray Harbor Mist Grey, and Armour Yellow because of the color fidelity and lovely glossy coat, which is ideal for decaling. I use plain old PAINT THINNER to dilute it for airbrushing, and it produces a near-perfect self-leveling glossy coat.

However, I am also using Tru-Color Paints (thinned with Tru-Color Thinner and cleaned up with Acetone) because of its color fidelity, ultra-thin opaque coats and ultra-fast drying times...it's great stuff!...and it produces a perfect (yup...it's that good) glossy coat when thinned properly (I think it to the consistency of whole milk) with Tru-Color Thinner.

Cheerio!
Bob Gilmore

[peteski]

Here are some related discussions:
https://www.therailwire.net/forum/index.php?topic=48982.0
https://www.therailwire.net/forum/index.php?topic=46059.0

And if you don't feel like looking over those threads, the spoiler is (extracted from one of the above threads):
Here is some interesting reading:
http://cs.trains.com/mrr/f/88/t/93640.aspx

Some state that DioSol is 80% touluene 10- 15% Xylene plus other.
I suspect this is the old "hot" formula.

Then someone else states:
According to the MSDS on Dio-Sol it's 40-45% VM&P Naphtha, 5-10% Xylene, 1-5% Ethyl Benzene, 5-10% Aromatic Hydrocarbon Solvent, and 40-45% Light Aromatic Hydrocarbon.
This one seems like it would be the REV1 formula (these are milder solvents).

If you have both chemicals, again do the spoon test. Take a  cheap plastic (polystyrene) spoons and apply some of each chemical to the spoons and see how it affects the plastic.

Another interesting thread about hobby paint thinners (although not directly related to this question) is:
https://www.therailwire.net/forum/index.php?topic=36484.0

Lastly, I have successfully used generic lacquer thinner for thinning Floquil Rev 1 paint. But opens another can of worms as not all brands lacquer thinners are created equal.  Some are hotter than others.  I use SCL brand (but it got hard to find in my area).  I have also discovered that the formulas of even the same brand lacquer thinner have changed over the years.  Paint chemistry is like black magic.  Always test any new combination of paint/thinner/plastic on a scrap piece before painting your precious model.

[robert3985]

@peteski - Peter, that is GREAT information!  I'm bookmarking it for future reference...

Cheerio!
Bob Gilmore

[Bobster]

Thanks all,

The later Floquil I used was thinned with Model Master not Diosol.

I must have searched wrong.  Thanks for the links.   Looks good will read this evening.

Bobster out

[Doug G.]

Floquil changed the formula for regular Floquil solvent-based paint. It was no longer as volatile and, in fact, was not as destructive to styrene and was able to be thinned with mineral spirits instead of Diosol or lacquer thinner.

Doug

[peteski]

Floquil changed the formula for regular Floquil solvent-based paint. I was no longer as volatile and, in fact, was not as destructive to styrene and was able to be thinned with mineral spirits instead of Diosol or lacquer thinner.

Doug

That is correct. Those were called Floquil REV.1 Formula paints.  It is those paints this thread was started about.  The name is funny because to me they are REV2 paints (REV1 would have been the original paints).  Still have few bottles in my paint stash (and they are still usable).



Notice that even when Floquil was in Amsterdam, NY, it was already part of RPM's family of coatings.  Some years later the "Rev.1 Formula" labeling disappeared, as all later Floquil paints became plastic compatible.

I also suspect that unlike what Bob G. stated, Floquil paints are enamels.  When they congeal in a bottle, you can't revive them just by adding the thinner (like you can do with lacquers).  It is enamels which cannot be reconstituted if they dry out.

[Doug G.]

They may have called the reformulated paints "Rev 1" because,in manufacturing, often, the original version doesn't have a revision number or is "Rev 0".

I still have a larger size bottle of PC green I bought in 1968 to match the PC green on Atlas kit cars. It is a perfect match and is still perfect in the bottle. It is,of course,the original version of Floquil. All my other bottles from that era, eventually dried up.

Doug