I want to paint (airbrush) an engine using Floquil Railroad Colors (not the water based acrylics), but don’t have any experiences with these paints. Can anyone please give me some advice on these paints, e.g. which thinner to use or if I need a primer etc.?

I usually use hardware store lacquer thinner, but I found out that regular mineral spirits will work for the newer Floquil formula. Since lacquer thinner melts plastic I've been using mineral spirits when spraying on plastic, just as a precaution. I probably thin it between 50/50 and 25/75 for airbrushing, and run about 25-30 PSI on my compressor. The air pressure and paint ratio i use depends upon the weather conditions, as I do all my painting outside.

I have used Floquil for years, and still like the product, even with the changes that Testors has made. I didn't know about the mineral spirits for thinning, and will try it myself ( on a test subject ). I used the original DioSol for thinning and cleaning, but now use the Testors "thinner", and clean with lacquer thinner. I have a vented spray booth where I do all my air brush, and rattle can painting. The paints can be sprayed without thinning, at the 20-25 psi pressure, but there are times where I prefer to thin slightly. I'll use a 25 (paint)/75 (thinner) when shooting a white " sunfade " weathering spray.
Floquil paint takes a while to thoroughly dry, and has a strong odor until it has dried, so if there is a "sensitive nose" in the house, you might want to think about a "drying place", as well as painting outside.

Thank you both for your valuable advice. Sounds like it is the same as with the paints I used so far: I can use normal thinner and the paint stinks , but as I do all my painting outside just like Kevin, it is no problem.

I've always use lacquer thinner for Floquil paints, both the old and the new formulae. In most applications, I like it about 50/50, although in some instances I use less thinner. For weathering, I thin it with up to 90% lacquer thinner, but don't recommend using it as a brush-applied wash. Thinned to this degree, it's possible to build-up very subtle weathering effects with your airbrush. Likewise, I don't like it for brush-painting plastics - the thinner will attack styrene when applied too "wet".
Depending on the material on which you're applying the paint and on the finish colour which you wish to use, their Grey Primer can be useful. Where you use, for instance, white styrene to modify a black styrene model, then add details in other colours or in brass, the primer will provide an even surface for the finish coat, giving the final colour a uniform appearance over all of the disparate materials.
Airbrushed, Floquil dries to the touch in minutes, but should be left at least 24 hours before re-coating or decaling. If you can still detect paint odour, it's not fully cured.
For spraying, I'd recommend a spray booth vented to the outdoors and a two-stage respirator - exposure to these types of organic chemicals can be very dangerous. Use lacquer thinner to clean your airbrush, being careful to not get it on any plastic parts.

Wayne

I will add to my comment that while I am now using low-odor mineral spirits for thinning, I still use lacquer thinner for cleaning up. I've never actually had an issue with using lacquer thinner to thin Floquil for spraying on plastic, but since I use lacquer thinner for plastic glue, it suddenly dawned on me that perhaps it isn't the best to use when painting plastic. Who knows, perhaps the lacquer thinner actually etches the plastic slightly, and helps the paint to stick better.

Traditionally, Floquil has been known to attack plastic. Brush painting it on bare plastic, or even plastic with a coat of paint, can ruin the surface. Supposedly, spraying so that it dries exactly on contact doesn't give this problem.
The old Dio-Sol could be used to clean and prepare metal surfaces.

I don't know when the new formula came out, but on my roundhouse project I used Roof Brown with lacquer thinner for the initial staining, and the pigments settled to the bottom of the jar. I also had a can of mineral spirits laying around and had wondered what I used it for. Then I recalled that I used it for the same purpose when working on the little one-stall engine house, and did not have this problem. So I would recommend using the mineral spirits, especially since you'll be spraying.

Thank you all very much!!!! I knew I could rely on you to provide me with all the necessary information .