Ask the Expert Question-and-Answer Archive

by Ron Joseph

Percent of Volume Solids

Q. I have data on % Wt solids present in my paint. Further, I know the specific gravity of paint & solvents. With these datas how do I determine % Volume solids present in paint.

A. Since you know the percent weight solids you can easily calculate the percent weight solvents by subtraction. If you need an accurate calculation of percent volume solids, you will need to break down the solvents into their individual components. This can usually be done from an MSDS. By going online you can look up the density of each solvent. Since the MSDS provides the percent weight of each solvent component you can calculate the actual volume of each solvent component by: vol of solvent1 = percent weight of solvent1 * density of coating/density of solvent1.

Add the volumes of all the solvents and you will know the total volume of solvent in the formulation. Subtract from the size of the container and you know the volume solids.

My explanation might sound difficult, but it really is quite simple.

Regards,

Ron Joseph