by Guest » Tue Nov 06, 2007 7:19 pm
Well, I doubt anyone publishes "mixed" density figures like kilograms per gallon.
First, convert in to liters (3.7854 L/US gallon). Then, from the name of the material, look up its density in some reference manual. It will be given in kg/L or g/mL (numerically equal).
Multiply by the density and you are done. There is no "universal" conversion, as a a liter of air ,feathers, water, and lead have VERY different weights.