Quote Originally Posted by Bass_Bug View Post
Ok, you've got me throughly confused. If Toluene is the solvent, then adding more Toluene to Shoe Goo which lists Toluene as the main ingredient (and then just petroleum distillate as the only other ingredient) does what? Make it thicker or thinner?
These sorts of things (well, pretty much any "glue"-type deal) harden through solvent evaporation. Basically, there's two parts mixed together in the bottle: the solvent, and the bonding material.

When you expose most of these things to air, the solvent evaporates and goes away, leaving the bonding material which is now hard and holding everything together. This is the reason why some paints stink like heck when they go on, but don't stink once they are dry.

Whenever you want to thin one of these compounds, you add the appropriate solvent before you apply it.