Water Base Poly in Tung Mix?

[Russ Filtz]

Was going to order some Rockler pure tung oil and saw some EF Poly & PolyAcrylic that was water based. I like to homebrew tung/spirits/poly for wipe on finishes. Question is, can the water based poly stuff mix well into tung? Guess I never noticed whether the poly I was buying is water based or not.

[Jason Roehl]

Not likely. The polyurethanes you are talking about are actually waterBORNE, not water-based. There is a difference. A simple explanation is that waterborne materials contain a chemical modifier that allows material traditionally dissolved in oil-based (or other chemical) solvents to remain in suspension or emulsion. Without having tried it, I would guess that the first drop of tung oil into the WB poly would look like a typical drop of oil in water--it would remain a cohesive drop and not visibly dissolve.