Advice for fixing "spots" in finish only visible under bright light

[bill epstein]

I was perfectly happy with these until a friend asked me for close-up pictures of an amplifier project and the flash revealed the two bright spots at the right edge of the left unit. Now I wish I hadn't taken the darn pic.

The finish is 1 1/2 lb. amber shellac over the walnut with a S-W Classics Varnish topcoat. Can't imagine what's causing the light spots. A few Watts tunneling their way out?

I have Winton Oil Colors I use with Field Oil for repairs but I'd rather not have to re-coat the entire chassis with varnish. The Oil colors used without topcoat never seem to dry. Any suggestions?

003.jpg

[Tom Bender]

Bill, those are beautiful pieces. Nice job wrapping the grain around.

I wouldn't worry about the spots.

[Lee Schierer]

My guess would be that they are glue spots that didn't see enough sanding. You can usually reveal these in advance by wiping down with mineral spirits.

[Wayne Lomman]

Mix a drop of your varnish, a drop of solvent and a spot of dye that is the correct colour and touch up with a fine pencil brush. Check the colour match in an out of the way area before applying to the front. Don't try to completely hide them, just blend them so they don't hit you in the eye. Note the 'precise' units of measurement. Artistic license is required. Cheers

[Rob Young]

My guess would be that they are glue spots that didn't see enough sanding. You can usually reveal these in advance by wiping down with mineral spirits.

This is quite possible. I've noticed that when I use the flash on my DLSR, it seems to "penetrate" the finish a bit and things show up that I can't otherwise see under various combinations of room light or daylight. I've speculated that it is because the camera "sees" just a bit into the infra-red and because of the image processing in the camera's processor, we get to see it shifted back into the red spectrum.

[bill epstein]

Mix a drop of your varnish, a drop of solvent and a spot of dye that is the correct colour and touch up with a fine pencil brush. Check the colour match in an out of the way area before applying to the front. Don't try to completely hide them, just blend them so they don't hit you in the eye. Note the 'precise' units of measurement. Artistic license is required. Cheers

That's a plan. Thank you.

[Tom M King]

If you can't see them without the flash, they are in the "ain't broke" category.