blue dye stain problem

user-90020 | Posted in Finishing on July 14, 2007 07:14am

I recently used a water based aniline dye (brilliant blue) on white oak, eastern maple and red mahogany and after the dye dried it looked great. Just like the picture, colour wise, and then I sprayed them with a catalyzed lacquer and they all turned green. How do I keep them blue?
I even tried a water-based polyurethane but that turned green.

Replies

SteveSchoene | Jul 14, 2007 11:37am | #1
Isn't chemistry great. Its not at all unusual for a dye to change color when a top coat is applied--in fact I'd say that is the norm. But usually that means it looks some weird chartreuse or something until the finish turns it back into brilliant blue. Or sometimes there is a reaction between a particular wood that gives an off coloration. But you have this same problem on three different woods, with two different finishes, neither of which is likely to carry that much amber (yellow) color to generate green from blue.

If your particular top coats both do in fact have an amber cast that could be the culprit and you would have to look for a water clear finish.

What brand of dye is it, and what is the name and/or number given to that color? Is it old? Was it mixed with distilled water, or something else? Perhaps you have a labeling error, or a bad batch. Have you used this particular dye successfully in the past?

This is a real head scratcher for me.
philip | Jul 14, 2007 11:56am | #2
How about applying the dye as you have done, then spraying a coat of Zinsser dewaxed shellac sealer, then your catalysed lacquer? Could be that the catalyst is reacting with the dye somehow, so separate them. One can but try.

Philip Marcou
EarlKelly | Jul 14, 2007 04:23pm | #3
Try a CAB laquer. It retains a fairly true color over dyes. Also, don't flood on your first coats.

You're water based poly should not have affected the color, unless they added an amber coloring to make it look more like normal poly. Normally, water based finishes have a slightly bluish cast.

Earl

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JMadson | Jul 15, 2007 05:04pm | #4
Try your different clear coats on a clean white surface and see how much yellowing you get.

I'm guessing your color problem is in your "clear" coat.
Dave45 | Jul 15, 2007 05:12pm | #5
I admit to having little experience with aniline dyes, but I would suggest that you contact the manufacturer and see if they can shed some light on why you saw a color change.

They may have seen or heard this before. - lol