Ask the Expert Question-and-Answer Archive

by Ron Joseph

December, 2005

Paints & Coatings - Converting from Solids by Weight to Solids by Volume

Q. I'd like to convert the Solids by Weight (SW) data provided by coating manufacturers to Solids by Volume (SV) so that I can then determine dry film thickness (DFT). Is there a formula to convert SW to SV?

A. To convert from percent solids by weight to percent solids by volume you need to calculate the percent volatiles by weight and then convert those to percent by volume. From an MSDS you can calculate the percent volatile by volume for each volatile ingredient, and then using the density of each ingredient, you can calculate their respective volumes. The solvent densities are available online. Once you know the volumes of each volatile component you can calculate the total volume of volatiles. By subtracting the total from a 12 gallon quantity, you will have the volume solids.

Best wishes,

Ron Joseph