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Sorting through some stored tops, I have two spruce tops from Vikwoods about 25 years old stored together with spacers. One set has black spots on both sides of one leaf, and one side of the other. My best guess is that they are stains from insect droppings. I tried sanding a little bit one spot, but it is deeper than just surface. So, is there a practical and effective way to "bleach" the stains. If not, the wood would become some sort of interior use (a waste) of maybe traded to someone who paints their guitars black.

You could try oxalic acid.

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"Act your age, not your shoe size" - Prince

wood bleaches can "eat" the cells of the wood, but chlorine bleach is somewhat less aggressive and might remove or reduce the staining.

its best if you know what you are dealing with , can you post pictures?

Does it look like a stain or dye? is it a mold or defect in the wood?

how thick are the plates you may see if the sand off or you must do a more aggressive removal.
Windex usually removes magic marker
Stains or dyes need bleach be careful if you use thinned as that can thin the stain or dye ,fade it but let it still set into the wood

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John Hall
blues creek guitars
Authorized CF Martin Repair
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You Don't know what you don't know until you know it

Did any photo load?

No.

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"Act your age, not your shoe size" - Prince

Please give me step by step loading instructions.

I use Tapatalk for loading photos. It works as easy as facebook…

I’ll try to help. First, tell me the source of the photos. Are they taken with an iPhone / Android phone, a digital camera, a go pro, Polaroid, etc..


Sent from my iPhone using Tapatalk Pro

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I'll try to help, too. Assuming an iPhone for taking the photos, and a Windows PC for the work of loading the photos into the OLF from a browser, here is the fairly burdensome way I do it without Tapatalk:

First, you need to get a medium sized version of the photo to be stored on your hard drive. I get there by e-mailing it from my iPhone to my e-mail account, and when a window pops up to ask what size I should make the photo, I choose medium. If you don't keep it at medium or lower, the photos might be too big for the OLF to accept.

Then, I go to my e-mail account (Outlook), find the e-mail, and locally save it to my hard drive. Then, I open it there and make sure it has the right orientation (it might need a 90 degree rotation).

Then, I go to the thread in the OLF where I want to post the photos, go to the Reply box (where you type messages), and pick the Full Editor button.

If you scroll down a little, you will see a Choose File button. Hit that, and navigate on your hard drive where the photo is, then select it. Once the loading process ends, you hit the Add the file button. That loads the photo into the OLF.

Lastly, you need to decide where to place it in the new message you are creating. Place your cursor in the new message box where you want the photo to go, and hit the Place inline button. It will load a link at that spot. Hit the Preview button to make sure this is all going to look right. Assuming it does, then hit the Submit button.

Like I said, this is somewhat burdensome, so I really ought to look harder at Tapatalk. But I’m a bit stubborn.

I took the photos with a digital camera and already loaded them onto my PC and they are on the desktop. I tired selecting the later steps motioned above, but nothing happened. I did not even get a message that the files were too large. I will try resizing them later and try again.

Curious what specie of spruce?
Vicwood sourced sitka from us back in those days. Are these stains round spots? maybe a greyish blue color?
If pretty dark and undisturbed, as in not sanded, do you see a small brown spec inn the middle?

If what I describe is whats going on, those are mold spots. The brown speck is the actual fungus, and the blue grey dark is micium i guess?
Those spots can get pretty deep. You may be able to sand the money face enough to get rid of the stain, But certainly not both sides. Regardless they are structurally sound and tonally unaffected. One could do a creative stain finish, or even make a solid color painted top. 25 yrs of aging with the sugars and pitches crystalizing makes that aged soundboard something special beyond looks.

Years ago when still in the old shop and under the house storage we had prior to 2015, I had boards get that in our inventory on occasion, after it was dried. It would happen when the RH has gone over 70% for long period of time.and the boards have picked up the moisture and became the perfect medium for fungal growth. We can also see the same in the dryroom if the dehumidifier quits working and the high humidity does that same. Rough sawn boards are thick enough to get rid of those spots.

I had some tops develop the blue staining Brent mentioned. If you can't cut around it ( edges and soundhole) or hide it under a fingerboard, then you might consider using it for smaller instruments. Staining the entire top grey/brown to make a faux Ancient Sitka top might also hide the spots. The blue staining sometimes goes pretty deep and if thicknessing the boards doesn't remove it I usually just try to hide it or cut around it, but if it is an especially nice top I would stain it or live with it as a "beauty mark".
Wood does improve with age, as Brent mentioned, so it would be a shame to cut those tops up for linings and such. I have some tops I bought 40 years ago that had turned brown with age when I bought them and they have made excellent instruments.
They don't make old wood like they used too!

I still have not been able to shrink my photos to load them on OLF. Geek Squad next. The spots are black or very dark brown. Some are raised up like substantial insect droppings. I guess Sitka, but I do not know. I guess eventually I will join them, thin them a little, and then decide. I am not interested myself in staining or treating them for darkening. One of my options would be to just trade with someone who does black tops. The pattern cannot work around the spots. It is not my highest priority. I won't really know the equality of the wood until it is surfaced--I see at least one area of strange grain.