Dried glue disappears on bare wood, but rears its ugly head when the finish goes on. Try these tactics to prevent-or fix-the problem.
glue spot.jpg

The Best cure: prevention

Your first line of defense is removing any glue squeeze-out before it hardens. Instead of wiping off wet glue, which can force it into the wood grain, let the glue dry to a rubbery consistency and peel it off with a putty knife. Take care not to squeegee glue into the wood grain. Next, shave the area where you removed the squeeze-out with a cabinet scraper. Then, sand to the same grit as the finish sanding. If squeeze-out has dried, remove the beads with a chisel or paint scraper, and sand the area.

Now, go looking for trouble

Usually, you can't effectively remove glue that has soaked into end grain. Instead, spread water-thinned glue onto the surrounding end grain to seal it. Then, scrape and sand the area to achieve even stainability.

To uncover glue spots before applying stain or clear finish, brush or wipe water or mineral spirits across the joint, photo below Scrape away any glue you find with a cabinet scraper, sand the surface, and test again. Water raises the grain, so after the wood dries, sand the area with the same-grit abrasive you used for finish-sanding.

It all shows up in the wash. Wet the wood along glue joints to find dried glue that will mar the finish. Water will soak into bare wood but not into the dried glue.

When the worst happens

Glue spots discovered after finishing (top), may require sanding and refinishing the part or panel. But first, try scraping, then sanding, the area with the same grit used to finish-sand the project, photos below. Then, reapply finish to the spot.

After fixing a clear-finished surface, sand the repair, feathering the edges of the finish to blend into the repaired surface. Then, touch-in finish with a small brush, and wet-sand the repair to even out the finish.

Scrape and sand glue from only the affected area, first photo. Test the area as in the photo on previous slide, to make sure you've removed all traces of glue. With finish applied and blended into the surrounding area, second photo.
  • Two ways to reduce squeezeout:
  • woodmagazine.com/excessglue
  • woodmagazine.com/gluegroove