Avoid Color Mistakes and Learn How to Fix a Blotchy Stain
Prevent stain and dye problems with a washcoat of shellac and learn how to repair a bad stain job
To avoid problems with stain or water-based dye, use a sample board to test the finish you want to use.
In addition, you’ll greatly increase the odds of having the color go on evenly if you apply a washcoat of thinned shellac beforehand. That will help ensure that subsequent coats of color take uniformly.
A good washcoat is a 1-lb. cut: Combine premixed shellac (which is a 3-lb. cut) and denatured alcohol in a 3:2 ratio.
|Control penetration. A light coat of shellac thinned to a 1-lb. cut creates a good foundation before coloring the wood.|
Fix a blotchy stain
If you use a pigmented stain that didn’t take evenly on the wood, what should you do next? Pine, cherry, maple, birch, and alder are the most likely to blotch.
If the surface is very blotchy, you’ll have to remove the stain by stripping, sanding, or both, and start over. This time, apply a washcoat of shellac and then the stain.
If the blotching isn’t too severe, try using a glaze to soften the contrast between the deeply colored and lighter areas.
Once the initial stain is dry, apply a washcoat of shellac. Let it dry, then gently scuff with P320-grit paper.
|Sand lightly. Pine is one of several woods that blotch easily. To even things out, begin by scuff-sanding.|
Brush on a burnt umber or other brownish glaze; wipe gently to remove most of the excess.
|Apply a glaze and wipe it off. Brush on a glaze to help cover up the blotches. Once the excess glaze has been wiped away, the door’s color is much more uniform.|
-Excerpt from 10 Best Fixes for Finishing Mistakes published in Fine Woodworking #192
Photos: David Heim