Ask the Expert Question-and-Answer Archive

by Ron Joseph

April, 2008

Q: What would the weight of one mill of zinc be on 1 square inch of surface area and how is it calculated?

A: Is this pure zinc, or a zinc rich paint? My calculation is for the average density of zinc metal.

One solid gallon of any compound covers 1,604 ft² at a film thickness of 1 mil.

The density of zinc is approximately 59.0 lbs/gal; therefore 1,604 ft² of zinc, at 1 mil weighs 59.0 lbs.

1 ft² = 144 in²

Therefore 1604 ft² = 1604 ft2x 144 in²/ft² = 230,976 in²

The weight of zinc covering 1 in² at 1 mil = 59.0 lbs/230,976 = 0.000255 lbs

1 lb = 453.6 grams

Wt. of zinc = 0.000255 lbs x 453.6 grams/lb = 0.116 grams = 116 mg.

Therefore the approximate weight of zinc covering 1 in² at a thickness of 1 mil = 116 mg.

Regards,

Ron Joseph