A friend is attempting their first overall paint job on their old Chevy and is having a little problem with their setup. Although their results are pretty good so far they are getting some dust and garbage in their paint and need some advice to reduce it.
The first thing about painting vehicles outside of a professional paint booth is that you are always going to have a small amount of dust and garbage in your paint. It is pretty much unavoidable but there are ways to reduce it and deal with it.
Your Paint Booth Is Not A Body Shop
This is one of the hardest things to get people to accept but if you work at a body shop you will notice that the only times that the booth doors are open to the rest of the shop is when they are moving cars in and out.
You might not be able to do this in your location but it is really important that you don’t use your shop space for bodywork. That includes final sanding of the primer. NO SANDING IN THE PAINT BOOTH.
The only time you might sand in a paint booth is between layers of base coat if you screw something up or get dirt in the paint. Even then it needs to be wet sanding and you need to be very limited in your sanding.
Always dust your vehicle off outside the paint booth before you bring it in.
Preparing Your Car For Paint
The first thing in a good paint job is preparation. Once you have done all the bodywork and sanded the primer to ready the car for paint you want to remove all of the masking paper and tape that you used up until now. Leaving masking tape on a vehicle for more than a few hours will result in it being glued to your moldings and everything else.
Additionally masking tape and paper hold dust. It only takes one pass with your paint gun to loosen up that chunk of primer or dust and have it set down right in the middle of your hood.
Use paper for masking not utility grade plastic drop cloth. A lot of people watch professionals paint and they use a plastic masking that is pulled over the car and then taped in place. This plastic has a special surface that holds on to the paint. If you use utility grade drop cloth from the big box store then the paint will chip off when the plastic flexes when your paint gun passes over it.This can result in a snow storm of paint chips and dust landing right in your fresh paint.
If you can’t use professional grade masking tape and masking paper then use standard grade yellow tape and news paper. Never use blue painter’s tape that is used for painting homes. Home Painter’s Tape has a low tack adhesive and will release from whatever its taped to when the first pass of automotive paint is applied. This can cause a loose piece of tape or paper to touch your fresh paint.
Tack Cloths And Wax And Grease Remover
You have to realize that although these materials are made for automotive paint production they are still a foreign product that may have some reaction to your paint. They should be used in a limited way to do the most for you.
After you have dusted and retaped your car and it is in the booth then at the very last moment you want to go over the surface with wax and grease remover. Using one moistened cloth to apply it and another to remove it. The cloths must be perfectly clean. Do not use paper towels that could have residual chemicals in them and will cause paper fibers to adhere to the primer. Cotton Cloths that have been washed, rinsed and dried are the best. As the cloths start loading up with dust continuously turn them so that a new clean surface is wiping down the panel. Only work in a few square foot area at a time.
Let the wax and grease remover vapor out for whatever prescribed time is on the container or about 15 minutes at least.
Tack Clothing is what you do once the paint is mixed. This is the very last try you have to get dust off the vehicle. You want to wipe down the area to be painted and you also want to wipe down your masking tape and paper. Turn the tack cloth as you lightly brush it across the panel. You should use an extremely light touch to not transfer any of the tacky substance on the cloth to the paint. DON’T SCRUB THE PANEL WITH THE TACK CLOTH.
Should You Apply Water To The Paint Booth Floor
Water is applied to paint booth floors for three reasons.
First it will keep any dust thats on the floor from blowing up into your paint. Second it will stop your paint from adhering to the floor and causing you more cleanup. Third it will catch any overspray and dust and stop it from bouncing back into the fresh paint.
It is a good idea to do this but it does not come without risk.
First you are increasing the humidity in the booth. If you are painting water based paint this can be a real issue but that is not the only problem.
If the water pools and you splash it on the surface to be painting that can be a real problem. Additionally just applying water to the floor is dangerous. If you apply it before the vehicle enters then the tires can splash the water. If you apply it after the vehicle is in the booth then you can get it on the surface.
Also you have to apply it just before you paint or it will be absorbed into the concrete or floor of the booth.
Is it something you should do? Yes. Does it have a lot of risks? Yes just as many risks as benefits.
Final Note
There are many other things that a professional painter has been trained to do to reduce dust in their booth but the most important thing is keeping dust out of the booth in the first place.
If you are cracking a hood to paint then you need to tape off the engine. If you are painting around the wheels you need to cover them with either tarp covers or the very least you cover them with big black trash bags and then be very careful you don’t blow dust off them while painting.
Your clothing is important and you should wear cotton clothing that won’t shed like a mechanic’s uniform with long sleeves or you should wear a painter’s jump suit. A mechanic’s uniform is really cheap about $20 for pants and a shirt and you should get a set.
Also dust yourself off with compressed air before you enter the booth.
Nothing is perfect but you can reduce problems if you follow proper methods. When taking advice about automotive painting or anything else you want to take that information from a teacher or a professional and not someone just painting their old beater in their backyard to get youtube views.
I am an ASE Certified Autobody Mechanic who has worked in the industry for many years and although I am giving you good advise it is only the very beginning of what you need to know to do your work properly. Much of it comes with years of practice and just doing things that you don’t even realize you are doing but become systematic.
My best advise is if you don’t want dust in your paint then don’t bring dust into the booth.