01-07-2009, 01:08 PM
Shane, the amount of thinner recommended will vary from one manufacturer to another, so it's best, at least when starting, to follow the instructions, either on the bottle or at the company's website. Most manufacturers also recommend their own brand of thinner, but there are cheaper alternatives, as most have discovered. The manufacturer will have a recommended spraying pressure, too, which is also a good starting point.
For practicing with your airbrush, don't waste your modelling dollars on artboard or canvas: instead, pick up a few corrugated cardboard boxes at your local grocery store or supermarket, then cut them up or break them down into manageable-size panels and do your testing on the inside surfaces, where there's no printing or labels. A very useful exercise (it was mentioned in the booklet that came with my Paasche VL) is to draw a suitably-sized grid on the cardboard, using a pen or pencil, then, with the airbrush, place a dot of paint at each intersection of the lines. The object is to place the dot as precisely as possible and to make it as small as possible, with no runs and with edges that are distinct (with little peripheral spray pattern). Different brands of paints will spray differently, and variations in the paint-to-thinner ratio will also affect the results, forcing you to develop specific techniques for each situation.
When you feel that you have mastered this, the next step is to connect the dots, with lines as thin and straight as possible. While none of your modelling may ever require you to paint it with connected dots,
these exercises will teach you how to control the airbrush, which will allow you to develop techniques to paint just about anything with confidence.
Before you start painting, though, there are two accessories that you should have before you start. One is a spray booth, vented to the outdoors, to cut down on dust (dry, airborne paint) and fumes. There are many available commercially, or you can make your own. This will also help to cut down on dust and paint odour in the entire house.
The second, and most important, is a two-stage respirator. These are not expensive, and most automotive supply stores or home improvement centres should stock them. A dust mask is not adequate protection, even for so-called water-based paints. And it is important to use the proper two-stage filters, too. The paper element part of these filters removes the particulate matter, mostly dried paint particles that will fill the air as you paint, while the second component, activated charcoal, removes the organic solvents from the air which you breathe. With the respirator properly adjusted on your face, you should not be able to smell any trace of any kind of solvent - if you can, correct the "fit". (To test the "fit", cover both filter canisters with the palms of your hands, then try to inhale: if you can breathe, there's a poor fit between the mask and your face. Properly fitted, blocking the intake of air through the filters should result in the rubber mask being drawn even tighter against your face, due to the partial vacuum formed when you inhale.). The disposable filters are good to use until either: breathing becomes difficult, indicating that the paper element is plugged, or, you can smell the solvents, even with the mask properly fitted - this indicates that the activated charcoal is no longer functioning properly. Discard the spent filter canisters (most are sealed units) and replace with fresh ones. With a decent spray booth, filter life is very good. I use the respirator even when spraying large items (structures, bridges, etc.) outdoors. (Incidently, it's best not to work in direct sunlight - not good for the "finish" on the paint, and you'll get strange tan lines from the respirator, too.
Wayne
For practicing with your airbrush, don't waste your modelling dollars on artboard or canvas: instead, pick up a few corrugated cardboard boxes at your local grocery store or supermarket, then cut them up or break them down into manageable-size panels and do your testing on the inside surfaces, where there's no printing or labels. A very useful exercise (it was mentioned in the booklet that came with my Paasche VL) is to draw a suitably-sized grid on the cardboard, using a pen or pencil, then, with the airbrush, place a dot of paint at each intersection of the lines. The object is to place the dot as precisely as possible and to make it as small as possible, with no runs and with edges that are distinct (with little peripheral spray pattern). Different brands of paints will spray differently, and variations in the paint-to-thinner ratio will also affect the results, forcing you to develop specific techniques for each situation.
When you feel that you have mastered this, the next step is to connect the dots, with lines as thin and straight as possible. While none of your modelling may ever require you to paint it with connected dots,
these exercises will teach you how to control the airbrush, which will allow you to develop techniques to paint just about anything with confidence.Before you start painting, though, there are two accessories that you should have before you start. One is a spray booth, vented to the outdoors, to cut down on dust (dry, airborne paint) and fumes. There are many available commercially, or you can make your own. This will also help to cut down on dust and paint odour in the entire house.
The second, and most important, is a two-stage respirator. These are not expensive, and most automotive supply stores or home improvement centres should stock them. A dust mask is not adequate protection, even for so-called water-based paints. And it is important to use the proper two-stage filters, too. The paper element part of these filters removes the particulate matter, mostly dried paint particles that will fill the air as you paint, while the second component, activated charcoal, removes the organic solvents from the air which you breathe. With the respirator properly adjusted on your face, you should not be able to smell any trace of any kind of solvent - if you can, correct the "fit". (To test the "fit", cover both filter canisters with the palms of your hands, then try to inhale: if you can breathe, there's a poor fit between the mask and your face. Properly fitted, blocking the intake of air through the filters should result in the rubber mask being drawn even tighter against your face, due to the partial vacuum formed when you inhale.). The disposable filters are good to use until either: breathing becomes difficult, indicating that the paper element is plugged, or, you can smell the solvents, even with the mask properly fitted - this indicates that the activated charcoal is no longer functioning properly. Discard the spent filter canisters (most are sealed units) and replace with fresh ones. With a decent spray booth, filter life is very good. I use the respirator even when spraying large items (structures, bridges, etc.) outdoors. (Incidently, it's best not to work in direct sunlight - not good for the "finish" on the paint, and you'll get strange tan lines from the respirator, too.
Wayne