Paint Application 101 - Painting Parts
Painting parts is easier and harder than large areas. The same principals apply as to painting large areas and you will need to follow the same checklist and techniques as the previous article with some modifications.

The most challenging aspect is getting the pieces set up so you can easily get paint everywhere. When I was spraying bike parts I had made up a variety of stands to hold the parts and usually had them sitting on some milk cartons I would stack to a comfortable height and cover with clean paper. I seldom hung parts unless I had to, as the air pressure tends to blow the pieces around, although in some cases this is the best or only option. If you are doing a lot of very small pieces at once, a touch-up gun is easier to handle as it spays less material and at lower pressures, although it is not recommended on larger pieces.

When spraying very small pieces you do not need a lot of air pressure, turn the air down to the point it still atomizes but is not blowing your parts around. It is not hard to wet small areas so use fast reducers/hardeners to speed up the process, and spray till just wet. Turning in your fluid tip a few ½ turns helps.

When painting headlight trim rings, fashion a loop from a coat hanger to slip inside it with a handle at the bottom – hold the piece in one hand and spray with the other – then hang to dry. If you are setting up larger panels on a table – put some empty rolls of masking tape under it to keep it just off the paper or the piece will get glued to the paper with paint. When doing fenders leave the outside in primer ready for final sanding, paint the inside, let cure then sand the outside and mask off the inside (same applies when doing hoods).

Trimming is referring to painting the inside areas like the door jambs (with the doors off), the trunk channel, the door edges etc., before you paint the outside of the car. This will enable you to get paint everywhere without having to open up doors, trunk, etc. when painting the outside resulting in a cleaner and more thorough job.

Always try to position your pieces so that the visible side is going to be easiest to cover and away from dust. If you are painting pieces in your garage (which I don’t recommend from a safety viewpoint) – sweep and wet the floor down- position your spraying away from any walls that might blow of dirt and have a fan venting out the fumes. Do not try and do too many parts at once in close proximity or the over spray will ruin what you have just sprayed. Make sure you can physically move around the part (with the airline) if you are painting on a table.

Paint does not work well below 60 degrees F and will take forever to cure, so have heat or wait for warmer weather or you will be wasting your time. Make sure your air is clean, run some sort of water and oil trap (a cheap one is the type that takes toilet paper cartridges). When painting new plastic pieces wipe them down with isopropyl alcohol and use a plastic primer (usually one coat - then paint). Fiberglass and plastic pieces get very statically charged when you wipe them down – spray or wipe down with alcohol as a final step before coating. When applying custom colors have a painted piece handy to guide you for the color, as most (custom colors) are determined by number of coats (and air pressure to a lesser degree). Tip: If you get a fisheye on the first coat let the paint set up and “bridge” it by dusting on paint over it before applying the next coat.

Most small pieces require a quick hand to keep them wet and covered with light coats and patience – you need to wait between coats to get proper results (follow the manufacturers tech sheets). The challenge is somewhat reversed on complete cars where it is a challenge to keep everything wet at once.

It is easier to control application on small areas – most show cars are painted apart or in the case of a custom color, re-cleared apart to get the best finish. Painting parts is a great way to get the feel for the paint gun and how the material goes on and if you screw up it is certainly easier to redo than a whole car.

Good Luck

John