Spraying top and "sap lines" showing up.....

[Kevin in California]

This is the first time it has happened to me, but I have to imagine I'm not the first person it has happened to.
My top these lines, random, dark like a grain line, that the lacquer sank into while spraying. At first I thought I had left deep scratches in the top, but I said to myself, "NO WAY". I did plenty of sanding up to 240 grit through out my process. After I sprayed a few coats, and level sanded, I was able to come down in these areas past the shiny lines, and had a perfectly flat, dull surface. These are in the center area on either side of my seam where the grain lines are tighter, various lenths and above and below the sound hole, and below the bridge area. None are out in the wider grains area in the bouts.
When I sprayed a couple of coats again, they showed up again, but again, I was able to sand flat and there is for sure they are filled.
Strange. Have you all seen these before in any of your tops? Is it like sap, or pitch pockets?
I don't mind the look, but sure didn't see them before I started spraying.

Kevin

[Kevin in California]

This picture shows these grain lines pretty well, in the lower part of the pic one that looks to not be filled.
I've sprayed more coats and these are leveling out now.

Kevin

[ken cierp]

Yes I've seen that and yes its a low spot --it may just take a few more coats than planned to get the coating build and levelling to a point where it disappears. Wipe your leveling areas down with naptha dampened rags that sometimes pulls the fine dust out of the low spots that is actually making them look dull.

[Kevin in California]

Thanks Ken,
I always think I've got enough lacquer on, and then discover that I really need more.
I sprayed to heavy coats this morning, and I'm going to spray two more tomorrow. THEN I may be finished.

Kevin

[TonyinNYC]

I remember readng about something similar at the OLF. The top had pitch pockets...or streaks actually, and the finish was not sticking to it. It is almost like the finish is being repelled away from the pitch streaks. Someone suggested shellac on the soundboard to seal it, then finish as usual and the problem was solved. Hopefully, you don't have to go back to bare wood to fix your issue.

[Kevin in California]

Sprayed two more coats last night,one this morning and a 50/50 thinned coat to flow out the surface.
It looks very good, I think I am done, and it appears that the top is filled....of course it is going to shrink some the next 3 weeks so we will see, but I know I can sand down to level in those areas.
So the wait starts now.

Kevin