Wiping Stain and Seal-Coat Compatibility

Be careful mixing a stain into a sealer — they don't always play together nicely. January 29, 2009

Question
A lot of times I try to hide blotchy issues when I stain by applying the same bit of stain to the first coat of sealer I put on. The look I want I always seem to get as far as blending out the differences in the stained surface. I use a fairly standard wiping stain from Sherwin Williams only to mention it for my particular type we use but occasionally the stain-sealer combo will leave this speckled/bumpy/white finish in places I know is probably from the stain and sealer not being very compatible with each other, wet. For a standard pre-cat lacquer sealer, is there a different stain type that might mix with clear coatings better than a wiping stain?

Forum Responses
(Finishing Forum)
From contributor J:
You are right to question the compatibility of wiping stains as some may be compatible while others are not. Many stains contain too much mineral spirits or other oily solvents to be compatible with mixing into a lacquer type finish.

To be on the safe side I avoid mixing stains into my finish altogether. Instead, try toning out the variations in the wood before staining by making a sap dye. Thin down an appropriate colored NGR dye stain enough to bring the lighter pieces up to the color of the darkest ones before applying your wiping stain. Dyes will not get blotchy when mixed and sprayed correctly and you can build a lot of color with them without obscuring the wood grain. A wash coat before staining will help with botching also.

I have done a lot of finishes with a dye, wash coat, stain or glaze type schedule, getting almost all the color from the dye and using the stain or glaze as little more than a color fill in for the profiles where the dye wants to stay light. If you feel you must color the finish, I would feel better using dyes or raw pigments (866 or 844 colorants) to do this. You have to be careful using the pigments though, too much and it will start to look more painted than stained.



From the original questioner:
Thanks for the insight. I will try using the dye as you described it within in my coating schedules when needed. Certainly gaining as much control over these things wherever possible is always a win-win deal.


From contributor R:

You could try this over your coat of sealer. Take the same stain and pour it into some lacquer thinner (strain it into a spray gun) and color in your light areas. Seal again and continue on with your finishing steps. Pouring the stain right into the sealer might cause problems down the road. If you’ve ever mistakenly used paint thinner instead of lacquer thinner to reduce your coating, you know what I mean. That gelatinous boogie is called gun cotton.


From the original questioner:
Yeah I call that a gun "booger". I will certainly try your idea though. I did a variation of your suggestion just yesterday where I reduced the fore-mentioned S/W wiping stain successfully but using Mineral Spirits and sprayed that over some un-sealed, but blotchy stain already on a piece that was dry. I had good success matching this one to the other already stained parts previously coated.

I really see the value of learning ways to control stain appearances on wood for so many reasons. Anytime I can manipulate or even just predict how something will end up looking - it is a huge victory in my finishing world.



From contributor J:
I would be careful spraying even a reduced wiping stain in a 'spray it and leave it" fashion. Too much pigment left on the surface, even over the bare wood can cause all types of problems from lifting/lack of adhesion to blushing/cloudiness of the final appearance. I'm not saying it can't be done with the right products in the right situation, but it is definitely not the preferred method.


From the original questioner:
Good advice. I'll be able to keep an eye on that particular stained part in that it'll be a permanent fixture to a portion of our business. I will also try the NGR dye first before the rest of the schedules I put together.