Problem – Dust in Clear Coat is this because of Static?

Tags: Paint Booth Filters


http://www.howtopaintcars.com/wp-content/gallery/shop-tools/paint-booth.jpg?i=997248100Professionals and hobbyists both battle the problem of dirt in their finishes and it seems that all of the technology available can not guarantee that you are going to get a job that is completely free of dust every time.

Recently I was talking with a guy that just installed a pretty expensive commercial paint booth system in his shop. He had been working with a handmade cross ventilation booth that he constructed but wanted to increase his production and felt that spending the money would be worth it in the end.

The problem he was having was random dirt that would show up in his clear coats. To help reduce the problem he was trying to ground his vehicle and his gun in hopes that the car if grounded wouldn’t be a magnet for dirt but he was still having problems.

First you should know that there are paints that react to static electricity. Powder coat enamels are often applied in open booths with paint guns that more or less float the dry paint on to the surface of the item being painted and the way this happens is the rack that the part is hung on by a wire has an electrical charge and so does the paint.

This is a huge benefit for people that powder coat parts in production because its a low voc environment and the static charge reduces the paint lost from overspray because it is specifically attracted to the part.

Another reason that commercial shops ground their vehicles is to remove static electricity which could result in a fire. A small static charge in a booth full of atomized paint and reducer could start a fire and although it does not happen that often it is better to be safe then sorry.

Where does Static come from in Paint Booths?

Static electricity really is difficult to fight in a paint booth because the movement of air through the booth for ventilation is the main culprit. Air which is often force dried in the winter months or naturally dry in the summer will always contain microscopic particles. These particles are too small to be seen or to cause noticeable problems in your paint but they do carry static electricity.

Some filtration systems can reduce static but when humidity levels are low.. something that is of value to a painter.. but you can expect static to be present in most booths no matter what systems you install.

Solution to Dust in Clear is it Static?

You have to consider that since static is always present you should do something to reduce its presence. A ground wire from the car’s frame attached to the booth or a ground will reduce some static. You should also ground yourself by touching a metal part of the booth when you first enter.

http://www.howtopaintcars.com/wp-content/gallery/shop-tools/paint-suit.jpg?i=1308744504On the other hand it is much more likely in my friends shop that preparation of his vehicle is the likely cause and not static.

Every car that we bring into our booth will have dust on it. It is best to wash not only the surface that will be painted but all exposed surfaces including wheel wells and the underside of the vehicle.

Not only is there dust on the vehicle but there is dust in our booth and on our clothes and on our equipment.

When you are painting you will build up overspray on your air hose and on your paint suit.

Basically dust is everyplace and the fact that we can get through a job and not have dust in our paint is more of a miracle then the fact we might have a chunk every few jobs that requires sanding and maybe a touch up.

In my friends case he had a brand new booth with lots of air flow that he was not accustomed to. Although it is great to reduce overspray it also moves a lot of air which can pick up particles from anyplace in the booth.

The fact is we are just not going to get to the point where we wash and wipe down our booths and filters prior to every job but what we can do is make sure the vehicle and specifically the masking paper and tape has been tacked really well.

Also wear fresh clothes in the booth.. if you are a hobbyist then invest in disposable paint suits.. if you are a professional change out your suit when needed. And whether a hobbyist or professional don’t wear street clothes in a booth.

You should also remove any items that are not needed. Empty boxes, trash cans and other items just suck up dirt and spit it out on your finish. If you feel the need for a trashcan then make sure it has a lid and put your mixing table near the output filters so nothing blows back on your job.