Rust Repair Maiden Voyage
You mix the hardener and the resin in a mixing tub, then you stir in filler until it's the consistency of toothpaste, then you put it in the tubes and use a standard caulk gun to apply it. They say you can use a dowel to push dried epoxy out of the tubes and reuse them. The pumps are designed so you get the right proportions of resin and hardener if you use the same number of pumps of both.