do you know what kind of paint it was? what brand? Was it gloss black?
Did they prep the primer good? wetsand it down? If they have runs in the primer, before paiting, that's not good. Sounds to me, they don't know what they are doing. Even if they came out of painting school.
The way I do it depends on the grade of what my paintjob will be. If I want flawless, near perfect paint job, I'll spend a lot of work hand sanding and preping the pieces. You need various sized grit sizes ranging from 80, 220, 400, 600 and if you want 800 and 1000 for a much finer paintjob, but totally not necesarry.
First off, you'd need to sand down what you have now. You don't need to dig in deep, just scratch the surface. If you have very thick paint on there or if you have some bondo work, use 80 to get the shape and smooth it out. Otherwise, just use 220. The technique for sanding is to be gental, don't rub it in. Just glide your hand over the piece your sanding with the sandpaper like your wiping your ass... wait what? lol
You need to be as even and consistant as possible with how much pressure you applying when sanding. Next is to use a 400 wetsand gritt paper. Use a bucket of water with a few drops of soap (lubricates the sandpaper to increase durability of the paper, otherwise they'll go out very quickly). Dip the 400 paper in the water and start wetsanding. Again, be as even as possible and make sure your being light about it, No need to dig in. If you sand lightly in one spot, you can feel the difference from the 400 and 220 easily. Sould feel much smoother to the touch.
**NOTE: humidity plays a huge factor when priming and painting. Try to spray when dry**
Once you get the whole piece wetsanded to 400, next comes priming. Priming is very important stage. You usually do a sealer, then a few coats of primer. But now days, primers are pretty good at keeping moisture out that you can use that as a sealer. This doesn't really matter if your painting on plastic as plastics don't rust. Primer is used so that paint has something to chemically bond to it very easily. Your spraying technique is also important as you want an even coverage. It's actually better to have overcoverage since you can just sand the primer down and get it level.
Just go side to side when spraying. Only spray when your hand is in motion and going in one direction. Don't keep it on when you change directions. Just keep it straight, even, level, and a consistant distance from the piece your primering (6-12", depends on the sprayer/nozzle/can). Before you spray, wipe the area down with denaturalized alcohol to clean all the oil and dust off. Then Spray the first level on thick. Double back and spray a quick light coat. Then wet sand with 400. Wait till dry (depends on type of primer) then wipe again with alcohol, two light coats of primer and wetsand with 400. Just remember, when wetsanding primer, just be as light as possible and don't dig in. If you over sand, you'll have to apply another layer of primer if you go through the primer and then you'll have an inconsistancy. Just make sure you get the area's where you overlapped in spraying called orange peels when you sand. They can show up and look awful on the paint job. Once you have the final layer of primer on, I usually sand it with 600 gritt lightly and wipe with alcohol.
And this point, your ready to paint, but I'd wait and leave the primer to dry for atleast 24 hours to cure properly, but depends on the type of primer. If you are doing a quick and dirty rattle can job, you'll have a lot more sanding to do. Otherwise, it's just spraying for now on. My experience is limited to stage 1 paints where the clearcoat is already mixed in with the paint. I find that they are easier to deal with since they take out quite a bit of work for you, but they really are good for solid types of paint jobs, which we are doing.
For a rattle can job, 1st coat is a heavy coat, but don't over do it. You don't want any runs or drips. If you still can see the primer, don't sweat. Wait 10 mins, then apply a 2nd coat. Then dry for an hour or so, sand with 400 or 600 gritt. Wipe with alcohol, spray another one or two light coats. wait 15 mins till dry. In between each layer and check to see if your making any runs or dripps, your best at sanding those out before moving on to the next layer as each layer on top of that will amplify the effect and ruin the good paint job. Remember, only do light sanding between one or two light layers.
You can go up in gritt size to 1000, even 1500 and 2000 if you want, but for rattle can job, you really hit the diminishing returns when you start using 1000. I say put a good decent 6 light layers of paint on the piece or until you don't see primer anymore. Lighter colors will require more paint/layers. On the last layer, use rubbing compand. Let the paint cure for a day or two.
Then you can get a can of clearcoat and add three coats of that. Wait 15 mins before each layer, you don't need to sand, but check the label and make sure, some clearcoats apply on foggy and require some light sanding. I have limited knowledge on clearcoats. After clear is applied, you can wax it using any kind of car polish but it's best to wait a week before doing so.
Now for a spray set with using a stage 1 paint, you don't need to sand anymore beyond this point. It's purely spray skills and time. Just do light coats and one pass only. Forget the 1st heavy coat. For every layer you spray, wait 15 mins, then apply again. Repeat until you are happy with the color. With one pass light coats, usually 8-16 layers is good. Depends on the color and what you want. Let it dry and cure for about a weekend.
Last edited by JBaz; 07-05-2006 at 05:14 PM.