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I have these odd looking black streaks showing up on the sides of some BRW.

They are not sanding out.

They do not appear to go all the way through the sides.

Not sure if you can tell from the photos - but these are not scratches or burns in the wood as everything appears to be smooth.

Never seen anything like this. Any clues what this might be? Is it just the wood???

Thanks

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P A U L B U R N E R
Burner Guitars

I'm guessing some sort of fungus stain--like spalting. I've seen a lot of dark stain on Brazilian stump wood. What I've seen didn't look quite like that.

Looks like a mineral stain. Something on the soil or water where the tree grew. You can see how it ran through the wood grain in the book match.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

it does resemble scuff marks, that are darker because they are deeper thus out of reach of the sanding medium. if you run your fingernails over the areas you can't detect a drop or change in texture...?

Have you tried hitting it with Oxalic acid to see if that removes the marks? Just an idea.


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Rob Flindall
Flindall Guitars
http://www.flindallguitars.com
https://www.facebook.com/FlindallGuitars

What is Oxalic Acid??? Never heard of it.

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P A U L B U R N E R
Burner Guitars

Wiki -
Oxalic acid's main applications include cleaning or bleaching, especially for the removal of rust (iron complexing agent), e.g. Bar Keepers Friend is an example of a household cleaner containing oxalic acid. Its utility in rust removal agents is due to its forming a stable, water soluble salt with ferric iron, ferrioxalate ion.
Basically it bleaches wood, best to test on scrap first.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

dark oxidatios in brw, also not following the grain is not uncommon, i think it is just in the wood, was it visiblie before bending? I also see this white line of minerals, would fit to the oxidation theory quite well.

cheers, alex

Judging by the angle of the dark patch comparing both sides, it appears to be boomatched. I think it's it's just darkness in the wood.
Being more prominent on one side than the other is consistent with that, especially as being flatsawn. If the patch was fading out at the point of resawing then we would expect one side to be more prominent than the other, and also that it might no completely through the wood, especially the side that's fading out more.

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Old growth, shmold growth!

Sorry Flipo...the streaks only "appear" to be across the grain....note that the ribs are book faced and appear to be off quartered which would produce the ringing pattern in the wood. However the grain is still running tail to head. Just like the streaking.

Some woods like say padauk when sliced up will reveal white streaked pockets. Many think this is sapwood. It is not.
Although rare, many any other woods will show pockets of darker streaking, BRW being one. Especially stump woods and woods that have started to spalt. THis may be from mineral staining or "pitch flow" or just the nature of the beast.

Looking closely at the pics one can see that the streaking follows the book matched length wise grain pattern. It appears to be a very thin streak in the wood as the kurf from booking the sides was enough to alter the mirror image of the streaks almost to the point of not being recognized as the same streak.
.

Me conclusions be ...1) the tree grew that way, or 2)fungus from spalting/starting to rot have discoloured the grain. It is natural just like the birthmark on my sweeties...never mind.

As to removal.... me only be guessing and personally wouldn't even bother, you know me being a Mr. Natural kinda guy.

Then there are others that wood say its the mark of the beast and that you should pack it and all its parts up and send them off to some one like me for proper disposal. ( Be sure to include the $500. disposal fee)



blessings

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Audiences and dispensations on Thursdays ~ by appointment only.


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My guess is they weren't there before you bent or you would have noticed then before bending and most likely flipped then over since you say they don't go through the wood. I suspect sanding will get rid of them.

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Joe Beaver
Maker of Sawdust

Sap not only travels up and down the tree within the anular grains, but across those grains as well via the medullary structures in the wood. Thus, mineral deposits and other discoloration can form in the wood in many ways.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

I see black stains like that anywhere near a wormhole, especially in BRW (I could probably dig up some pix of wood with that in it, I am sure I have some kicking around) .... its in the wood, and I doubt you can sand it out .. you will have no side left if you did ... aint Mother Nature sweet ....

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I'm with Brian and Tony. I've seen a lot of tropicals with that sort of staining. If you sand that out I'll be the first to admit being wrong. Frankly it adds character. T

I think that the stains give character to the sides.
I've have used many tropical woods with these.

As stated probably mineral .
those white spots on both sides usually mean mineral deposits.

But if the log laid on the ground it could be fungi.
Any soft punky feel to that area?


The finish will probably make them look great!

go for it do not let them bother you.

Mike

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Mike Collins

Well Paul,

you probably would not take this suggestion to heart...however me has worked with a lot of spalted woods....were the
darker spalting streaks and worm holes disappeared...the clear wood areas looked out of balance and so me would drill in a few tiny worm holes and drop fill with dies...even streaking the dies to emulate the spalted areas. This balanced out the natural bland areas...when done properly, it was undetectable to the natural spalting.

Being an artist/painter me was able to pull it off.

Not suggesting you do this but just something to thinks about.


blessings

_________________
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Audiences and dispensations on Thursdays ~ by appointment only.


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So, where are you on this? It would be interesting what you have found.

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Joe Beaver
Maker of Sawdust