TotalBoat Penetrating Epoxy can be thinned up to 100% with acetone, denatured alcohol, or lacquer thinner*. Always mix the resin and hardener epoxy components together prior to adding any solvents.
As an example, if you have 3 ounces of mixed epoxy (2 ounces of resin and one ounce of hardener thoroughly mixed), you can add up to 3 ounces of acetone, denatured alcohol, or lacquer thinner.
*The solvents listed on the product, and this article are the only solvents that should be mixed with TotalBoat Penetrating Epoxy. DO NOT attempt to use any other solvents.