White Flecks in the Pores Under Tung Oil

Filling the pores before finishing is a good preventative; tinted wax can be a workable fix. January 18, 2011

I have a tung oil finish on claro walnut that is around 6 months old and is showing some white flecks in the pores that do not go away with reapplication of the tung oil. What is this and how can I get it to go away?

Forum Responses
(Finishing Forum)
From contributor J:
I often fill the pores on walnut to keep this from happening. Dust gets in the pores, which results in light pores on dark wood. In that case, you can use a tinted wax to fill the pores.

If it isn't dust, maybe it's poorly dried (too thick) tung oil. I would still try the tinted wax, since more oil doesn't fix the issue. I use Liberon Black Bison, though there are other brands.

I like to fill the pores with Rockler's Wunderfil. Louis and Co has a great waterbased filler too, but it smells like an electrical fire (though it's supposed to be non-toxic). Many of the oil based ones have resin in them, which may not work so well under an oil finish.
If this was a tabletop, it could be that oil built up in the pores and couldn't leak out. You may consider blowing compressed air into the pores and wiping off the excess to keep the oil from drying too thick.

From contributor G:
I was thinking it is poorly dried tung oil seepage, but mostly am wondering if a 320 sanding will help get rid of it, or is it only fixable with the wax solution?

From contributor R:
Those white flecks you're seeing might be sap or mineral deposits. You see quite a bit of this on mahogany as well as walnut. Short of removing the tung oil and starting over, a colored wax as suggested above might help mask those areas. Depending on how open the grain still is, it could be the cure. Have you ruled out the possibility that it's glue residue creeping up through the pores?