High Performance Water Based Varnish - Flat - Pint

Blocks wood dye

This is probably an off-label use for this lovely product, but I had to submit this for posterity because it saved me so much trouble. I live in an apartment from the early 20th century. It seemed to be popular in that time to install nice hardwood (cherry?) doors and trim dyed to a very dark red mahogany color with an (aniline?) wood dye and then varnished. Over the decades, this hardwood got painted and re-painted probably a dozen times. The first coat of paint had poor adhesion to the varnish and was blistered and would come off in thick flakes, leaving conspicuous contrast between the light paint and the very dark stained wood. After doing various door and trim repairs and stripping off loose paint, I went back to re-painting the wood. Wherever the original varnish was not in perfect order, the wood dye comes through almost everything as a nasty bright pink stain. It will diffuse through dried latex paint or primer over the course of a week or so. It will also come through oil-based paint or primer instantly, as it is soluble in organic solvents. Maybe half a dozen coats of oil-based primer could block it. Maybe. I got close and was still getting some pink. I finally thought to re-varnish the places where the dye was exposed. This flat waterborne polyurethane ended up saving the project. Not too smelly, not too viscous, and with a decent drying time, two easy coats of this stuff, followed by primer and paint, blocked the dye completely. The flatting agent made for great adhesion with the primer. Almost a year after my first use of the product (having gone through an extremely cold and dry Chicago winter), I have had no adhesion problems. Given how smoothly it goes on and the beautiful subtle luster of the flat poly finish, it's almost a shame to use this product for such a utilitarian purpose. But if this saves someone else some time, I'll be happy.