Powder Coating for Dummies

Powder Coating QA

Powdercoating Questions and Answers

The Baking Temperature

When explaining powder coating for dummies to a novice, I like to use the analogy of comparing powder coating to porcelain.

Porcelain, a glass based material, is baked on at very high temperatures and will chip very easily under impact.

In fact, it will probably chip all the way to the substrate (bare metal). Powder coating is similar in some respects. It does have some flexibility but not the same as a straight petroleum based paint.

Avoiding Risks Failures

The secret to getting a quality powder coated finish is the experience of the applicator. If you go to a professional shop that advertises powder coating as one of their services you are probably going to get a high end job that will perform well.

If you opt, instead, to use some of the do-it-yourself powder coating for dummies you are running a very high risk of failure.

Powder applications work best on raw materials that have been chemically treated with phosphate. This chemical treatment sets up a coating and promotes adhesion.

Powder Coating FAQ

The Importance of Temperature Control

The coating process itself is relatively easy. Your primary goal is to attain a uniform thickness and is controlled by a good sprayer vs. a bad sprayer.

The next very important and critical step is the baking cycle. The object being baked must reach a recommended uniform temperature for a certain length of time.

This doesn't mean just the surface temperature. The complete part, inside and out, must be at the temperature required. Otherwise, the part acts as a heat sink and cools too quickly.

Example:
You coat a heater blower housing made of a thin gauge sheet of steel. This part will come up to temperature relatively quickly.

Powder Coating Q A

Real Life Examples

Now lets go to the extreme and say you’re going to powder coat an engine block (By the way I don't recommend this). The time it takes to get this block, inside and out, to the 380-400 degree range is astronomical.

If the applicator pulls the product from the baking cycle too soon it will appear to be beautiful. Unfortunately, the adhesion will not be there.

The end result will be a very brittle powder coating which has bonded improperly to the substrate and chipping is a certainty.

If you do chip or scratch your coating to bare metal YOU MUST SEAL IT. This can be successfully accomplished with a touch up paint or even a clear finish.

Powder Coating Questions

The Problem with Cheaper Paints

Powder coating is so hard that rust will appear on the scratched bare metal. Here is the big problem: IT WILL MIGRATE UNDER THE REST OF THE COATING!!!

It becomes like a little greenhouse under the undamaged area trapping unseen moisture as if it were in a pitch black cave.

As the sun’s UV rays hit the trapped moisture area(s) failure of the seemingly good powder coated areas starts occurring. The result is loss of a beautiful finish, for no apparent reason!

Not Everything That Shines Is Good

Example:
How many times have you seen cheap stacking chairs, bought from K-Mart or Wal-Mart, stacked at the curb for garbage pickup?

Close inspection reveals a powder coated surface full of rust! I know for a fact that these are powder coated because I use to paint them for a huge price of 55 cents per chair!

You see, chain stores figure that when you wear them out you will be back for more. They don’t care if they eventually rust.

To powder coating for dummies the primary objective is to look pretty so you will purchase them.

Poor Quality Job is Going to Cost You More Money

I suspect you don't want to buy new Thunderbird parts every year, so be careful and take care of breaks in the coating as soon as possible to avoid these problems.

If you’re going to get items powder coated pick a reputable shop. Ask them for powder coating for dummies's references.

If they do a lot of automotive work they know who their customers are and should be more than willing to let you speak with them.

You wouldn't send your bumpers to somebody that plates in old garbage cans so don't be so quick to compare prices on this type of finish.

A quality job will last a long time. A poor quality job is going to cost you more money in the long run when you have to strip them and do it all over again.

Powder Coating for Dummies

The Importance of High Impact Powders

Why powder coating for dummies then? To my knowledge, no manufacturer sells under this premise. There are various grades of hardness but this is determined by the type of powder: epoxy, polyester or hybrid.

The hardness difference is minimal. I have used epoxy powder coating on under body components simply because resistance to chemicals is better than the polyester powders.

Once again, epoxy powders do NOT have good UV light resistance and tend to fade over time. If you are doing a restoration project, and want to stay close to the same color black that the factory used, you should be looking as something in about a 20 to 30 degree gloss level (preferably near the lower end).

Gloss Degrees are checked with a Degree Meter which passes a beam of light across a painted surface to measure reflectance. It was developed for the military to sense the visibility of an on coming aircraft.

Gloss Levels:

• 0 to 15 degrees is almost dead flat
• 16 to 40 degrees is considered a semi gloss
• 41 to about 95 degrees is considered as high gloss

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