Need help finishing over aniline dye.

[Tom Pritchard]

I could really use some advice. I have a maple aquarium stand that I built for my son that I am in the process of finishing. I used aniline dye to color the maple, and then applied a coat of sanding sealer after the dye so that I could use a water based poly for the final coats. Within a couple brushstrokes of applying the waterbased polycrylic, the dye began showing up on my brush. I had no dye leech out when I applied the sanding sealer.




Will a solvent based poly be ok to apply over the aniline dye without it bleeding through? Thanks in advance for any help you can offer!

[Rob Amadon]

Tom,

What kind of and how much sanding sealer did you use? What brand of dye is it?

If the dye is strictly a water soluble dye (i.e. not transtint or something similar) you can use a coat of de-waxed shellac in around a 2 pound cut to seal the dye in. You can then finish it with whatever you want.

I would use a oil base, non poly, varnish myself, specifically Behlens Rockhard or Waterlox Original(satin or gloss). Those two varnishes are both made with tung oil and phenolic resin which combined with the shellac will give a very water resistant, tough finish. If this is going to be in direct sunlight oil base poly will yellow and degrade quickly and I wouldn't trust the polycrylic in a damp environment.

Rob

[Jim Becker]

If you used water soluble dye, it's very difficult to brush a water borne finish over it as the dye will be re-disolved. The solution is to seal with de-waxed shellac as Rob suggested. Alternatively, spray your water borne finish rather than brushing or wiping so you don't pick up the dye. The finish will dry quickly. But even with spraying, I always seal water soluble dye with de-waxed shellac anyway. BTW, you don't need to use the "sanding sealer". Just use the shellac. The sanding sealer is an excellent way for the manufacturer to make extra money off you, but it provides little benefit. (The exception would be lacquer-based high-solids sealer that melds with subsequent lacquer coats into one layer of finish)