Walnut turns white

[Tom-W Scott]

I raised some walnut panels which I stained with Minwax.....so far so good.
Thne I used Minwax clear poly over the stain.
The cross grain machined surfaces turned white. All other surfaces are OK.
Any ideas what happened??

[Steve Schoene]

I've never seen this sort of thing, though I do wonder what you mean exactly by cross grain machined surfaces. All finish sanding must be done with the grain to avoid visible scratches.

[Dennis Peacock]

Don't know about the poly, but I do know that if you finish with lacquer and it's really humid in the shop, it will "blush" on ya and give you a whittish haze to the finish.

[Tom-W Scott]

Dennis & Steve
Thanks for the replies.
By cross-grain, I mean the ends of the panels where the router bit cut across the grain when raising the panels.
I should add that this is "reclaimed" walnut from an old cabinet. I used Strip-Eze to remove the old finish ....it may have been varnish...high gloss.
Then I sanded sit thoroughly before machining.
Is it possible that some of the previous finish may have penetrated more deeply than the stripper reached???

[Jim King]

Don't know about the poly, but I do know that if you finish with lacquer and it's really humid in the shop, it will "blush" on ya and give you a whittish haze to the finish.



I think Dennis hit it perfectly, the hotter and dryer the better when applying finishes and only on dry wood.

[Harold Piper]

Tom

If you used lacqure for the finish try spraying the "white area" with lacqure thiner, this should take the blush out.

[Jeffrey Schronce]

OP states he used Minwax Poly rather than lacquer.

I had a problem once with a chalky white result with Minwax Poly. I noted that some of the solids in the poly had settled to the bottom of the can and created a layer of white goop. I used mineral spirits to remove the offending poly and reapplied with fresh poly. Is your poly fresh or is it old, having been exposed to heat/cold and a lot of oxygen in the can?

Very likely that is not the problem but I thought I would mention it since I had it happen once.