Pactra acrylics are great paints. Thinning, I recommend using the same medium as Faskolor: rubbing alcohol. Rubbing alcohol has a lower surface tension than water making the paint spray easier. Windex works the same way and the blue dye does not affect the paint.
Rubbing alcohol dries quicker than water. Because of this, there's less chance of the paint being pushed around on the body by the airbrush spray. It dries much quicker than water allowing you to move on to different colors quicker.
I usually thin all my paints before I spray. I thin to the consistency of milk...every time. I have very little to no problems when I spray. Each coat of paint needs to be very light for durability.
When it comes to clean up, use plain rubbing alcohol. At 75 cents for a large bottle, it's pretty cheap. Just clean up the brush inside and out with alcohol. When done spraying at the end of the day, just spray a full color cup of windex or windshield washer fluid and store your brush.
Compressors are a common question for painters. While the hobby compressors are nice because of their diminutive size, they add a few more problems. The pulsing action of the diaphram can make a solid line look dotted or splotchy. It's quite difficult to do good drop shadows with these compressors because of the pulsing.
I strongly recommend you go to Sears or Harbor Freight and pick up a standard tank compressor. A good tank compressor, about a 3 gallon jobbie will fulfill all your needs. Pick up a good moisture trap for it and you're good to go. Most compressor fittings are 3/8", so your airbrush hose won't need any adapters to fit. A good moisture trap is a must, though, and can be had from 10-20 bucks. In total, you can expect to pay about a hundred bucks for a compressor and moisture trap. Campbell Hausfeld and Craftsmen are good names to stick by, and they usually come with decent regulators.
I also recommend picking up the quick disconnect kit for it. You'll find plenty of uses for your compressor other than painting. Filling up the football or car tires, cleaning off your car/truck after running, using it as an excuse for a good air-nailer, you get the picture.
The amount of pressure you should spray is another common question. This is where practice comes in. Learn to thin your paints so that paint flows smoothly at your desired pattern. The variables involved are paint consistency and air pressure. Play with each to come up with what you're looking for. Some paints spray beautifully at 20 psi while others spray better at 30 or even 35 psi. I've even sprayed at 55-60 psi with excellent results. I preach to people starting out to take notes when spraying. Note the type of paint used, how thin it's sprayed, spray patterns achieved, and psi used. This will help you next time you go to pick up a paint. I have a 200 page notebook full of such notes as well as tips and tricks picked up from really great painters. Before I paint, I constantly refer to it to refresh my techniques and my paint parameters.
On a final note, if you have Pactra Lacquers and Acrylics, be careful when switching from one to another. It's ok to spray acrylic over lacquer, but lacquer over acrylic can easily end in disaster (lacquer eating the acrylic). Also, remember the brush. If you mix lacquer and acrylic paints together, you get a sludge that dries quickly and like concrete. Before switching between the two types of paints, thoroughly clean your brush inside and out...then clean it again. Do NOT leave any chance of lacquer coming into contact with semi-dried or dried acrylic unless you want a huge headache of trying to figure out why your brush won't work.
Sorry for being so long winded, just trying to make your experience as frustration free as possible.
Before I forget, if you run into spider webbing, there's a couple of things you can do. First, drop down the pressure a tad. This usually does the trick. I've also heard that spiderwebbing is commonly caused by static build-up. To combat this, prior to spraying wet a paper towel down and wipe down the OUTSIDE of the body. No need to soak it, but don't rub a dry towel on it either. A good wet paper towel not dripping will do wonders. I do this now just as a precaution.
