Seeing Spots

[Larry Beyer]

HELP
My newly sanded Black Walnut wood exhibits some spots…they appear to be a deposit of sanding dust. The wood pieces have all been sanded to 220 grit ready for finish. There’s not a lot of spots and they are random; sure ruins the appearance.
On one piece I took and sent it thru the planer again; the spots disappeared. I then sanded it by hand rather than the quarter sheet machine with 220 grit; two small spots appeared in a different place.

On the second piece I resanded with 100 grit using the machine; the spots are gone. The others I have just left alone. I cant seem to get beyond 100 grit without having the problem reoccur.

What is causing the problem?

What do I need to do so it does not occur again?
Thanx in advance

[Earl Kelly]

Larry, don't really know what is causing your problem. But, you can see how the wood will finish by wiping with MS or Naptha, this will show evrything the wood has to offer, including spots or defects, as well as the beauty. I would guess if you do this you'll see the spots are not showing anymore. If they show after wiping with MS, sanding has nothing to do with the spots. Then, they could possibly be some mineral deposits or something similar.

[Steve Schoene]

The naptha wipe down before finishing is a generally good idea. It reveals glue smears before you have to scrape off the first coat of finish. DAMHIKT.