Originally Posted by 69 widetrack
On another note, if reducers didn't enter a substrate to form chemical bond, why would some be harsher than others, why would there be a need for some reducers that if not used properly that can actually wrinkle an existing finish...if all that was left was mechanical adhesion...that's one problem that most of us have experienced. Reducers, acetone, varsol, gasoline are all solvents, Lacquer paint is cut with Lacquer thinner...what does lacquer thinner do to lacquer paint, it will take it off if to much is used, if the right amount is used it will penetrate the lacquer paint and again, give a chemical bond.
It all goes back to everything I said earlier about solvents. Solvents dissolve their respective substrate. If you add a lot, it dissolves it all, if you only add a little, it only dissolves a little bit. Eventually the solvent evaporates and you're left with your substrate. Add a teaspoon of water to a pile of sugar, the sugar gets wet, only some goes into solution. Add a gallon of water to sugar, the sugar disappears and goes into solution. When the water's evaporated, you're left with a pile of sugar. It's the same thing that's occurring with lacquer thinner. Solvents have varying degrees of harshness because it all depends on those four chemical properties I discussed earlier.
If the solvent can simultaneously solubilize two different substrates, maybe molecular cross-linking can occur between these two substrates, in which a 'chemical bond' would occur.