Finish discoloration. What happened?

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Forum topic by JTWoodworks posted 09-14-2017 02:39 PM 548 views 0 times favorited 3 replies Add to Favorites Watch
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8 posts in 1029 days

09-14-2017 02:39 PM

Topic tags/keywords: finish finish discoloration finish help suggestions im new here new member i need help general finishes radiator covers question

About a year ago I made radiator covers for an office. The top is made with walnut veneered mdf that’s trimmed with solid walnut. I used General Finished High Performance water based top coat. The fish in the veneer is holding fine, however the finish on the solid walnut is discoloring. What happened? Is it possible that it was affected by the heat from the radiator? I did put insulation under the top to protect it. The discoloration looks like a white haze.

I’m thinking it could be from sanding between coats with steel wool. Maybe the steel had a reaction with the water based finish. But like I said, I made these a year so I don’t remember if I sanded with steel wool or sandpaper. And it definitely seems to be the finish and not the walnut.

Thanks in advance for the help!

3 replies so far

View chrisstef's profile


18094 posts in 3781 days

#1 posted 09-14-2017 03:23 PM

Were all sides of the solid walnut finished? My guess, and its only a guess, is that the open pores left unfinished are wicking in moisture and the heat is forcing the moisture out of the wood and what youre seeing is trapped moisture between the wood and the film finish.

Thats my guess.

-- Its not a crack, its a casting imperfection.

View Woodknack's profile


13392 posts in 3154 days

#2 posted 09-14-2017 04:48 PM

Post pictures

-- Rick M,

View Hammerthumb's profile


3055 posts in 2750 days

#3 posted 09-14-2017 05:24 PM

Although you are not supposed to use steel wool and water based finishes together (water based can rust any left over steel wool particles), I think Stef’s answer is more on the right track.

I agree with Rick. Need to see pictures.

-- Paul, Duvall, WA

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