How much coverage from a pound of fine texture Powder Paint Black?

A. Hi Doug. It will depend on what kind of powder it is, with some thermoplastics approaching 10x the film thickness of some thermosets. The manufacturer's tech data sheet should give you coverage and thickness, but you could figure 3 mil (thousandths of an inch) as an average thickness for most thermosets.

A. The amount of usage depends upon the manufacturers "specific gravity" found on the powder spec sheet and the operator or equipment transfer efficiency.

Say the spec sheets says your powder has a specific gravity of 1.5. You take 193.2 (baseline) and divide that by 1.5 (specific gravity) and get 128.8 sq ft. You have to remember that this figure (128.8) is for 100% transfer efficiency which never happens and for 1 mil of powder which is not usually the case. You have to divide 128.8 by half for every extra mil you apply and you have to take into consideration your transfer efficiency as well. So if you only had 50% transfer efficiency, you would divide your end result by 2 again.

Example = 193.2 / 1.5 (specific gravity) = 128.8 sq.ft. / 3 (mils) = 64.4 sq.ft / 80% transfer efficiency = 51.52 sq. ft.

Generally, the lower the specific gravity, the more coverage you'll get. Hmmm...clear as mud?

Bob Utech Benson, Minnesota

Ed. note: Bob is the author of: "High Performance powder Coating" on eBay or AbeBooks or Amazon [affil links]

A. Dear Bob,
The maths does not quite work out.
128.8 /3 = 42.93.
Therefore at 80% eff you would obtain 34.34 sq ft/lb.

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Sorry I meant 2 mils.

Bob Utech Benson, Minnesota

Ed. note: Bob is the author of: "High Performance powder Coating" on eBay or AbeBooks or Amazon [affil links]

2007

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Probably my fault. 2 mils is a more generally accepted thickness than the 3 mils I mentioned. Bob was probably trying to not contradict me, yet had 2 mils locked in his mind for the calculation :-)
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007

A. Gentlemen, both replies are good "starting points" but the amount of "fines" (particles too small to hold an effective charge) in the material is not captured by the specific gravity data, nor by transfer efficiency (theoreticals are generally based upon uniform or "controlled" material and is giving an equipment value).

Given that, you would likely have two very different coverages from two different paint suppliers even if all other variables are the same for the test (including s.g.).

The takeaway is to test various materials from a variety of suppliers to see which provides the best coverage for YOUR specific application (some paints simply apply better than others with certain equipment based upon how they are formulated). Talk to your painters, ask them which "seems" easier to work with and which covers faster.