Stains / streak in swamp ash. Removal method?

[Asdrael]

Hi there!

I'm getting my first build of the ground (I'll make a thread as soon as it really starts for it so you can witness the wreck in real time) and I was wondering;

I received a swamp ash body blank that revealed some stains (mineral streaks?) after thicknessing. They appear grey/black/darker-ish and don't particularly seem to follow the grain pattern (see picture, right side). They don't go away with acetone nor with water. Since they are on the very side of the blank, only a small portion would show once the body is but (and likely on the back side due to how I like the grain) but I can't help it: is there a way to remove those that I should know about? Since I don't really know what it is, a google search is difficult, nothing comes up except "how to remove the glass stain your granma left at the last family dinner when she tipped over her second gin tonic glass after falling asleep in at the table".

Cheers!

[Bizman62]

Hi and welcome!

"Mineral streaks" is as good a name as anything for features that are hidden inside the wood. They are a biproduct of the manufacturing process performed by Mother Nature and as such they're usually impossible to remove. Often on the contrary, such anomalies can be sought after for a more interesting surface!

Compared to straight grained knotless wood such spots may be weaker but for guitar/furniture building there's nothing to worry about. For the main beam of a bridge one might choose another piece just in case. For items that don't carry the weight of a truck there's nothing to worry about.

That definitely looks like something that has grown into the wood, the roots have encountered a spot of liquid mineral (like rusty water) which has been sucked into the tree trunk, causing some discolouring. As the mineral particles are bigger than plain water they only can spread so far, that's the origin of the darker outlines.

There's other reasons that can draw lines and discolouring into wood, fungi is one of them. In that case we're talking about "spalting" where dark lines make the board look like a map showing borderlines. There's also more or less rottening involved, some spots may look perfectly healthy while other places may be spongy. Spalting usually starts at the cut end of the trunk/board or around a broken/cut knot. A lengthy contact on moist ground is also usually involved. Even those can well be used for guitars, either as decorative tops or entire bodies.

Nothing to worry about with that piece of wood!

[Asdrael]

Thanks a lot for the detailed reply. Judging from the small "entry stains" on the end grain, it's extremely likely that this tree had at some point during its growth a bit of a change in its water composition supply.

I am actually going to call it a birthmark. My first born has a small one, so it's only fitting my first build has one (now let's hope it won't end up as firewood... yes I'm talking about the guitar). Hey, the guitar will be called birthmark. Thanks for the idea

[mistermikev]

5 hours ago, Asdrael said:

Thanks a lot for the detailed reply. Judging from the small "entry stains" on the end grain, it's extremely likely that this tree had at some point during its growth a bit of a change in its water composition supply.

I am actually going to call it a birthmark. My first born has a small one, so it's only fitting my first build has one (now let's hope it won't end up as firewood... yes I'm talking about the guitar). Hey, the guitar will be called birthmark. Thanks for the idea

as mentioned, mineral stains.  nothing going to take that out other than possibly creative carving.  I would cut a template out of paper and draw your guitar on both sides and see what it will actually look like and how you can minimize it. 

 

Better yet, go buy a cool tamo ash veneer from b and b... 2 * $11.  You won't even see the transition on the sides if you blend them right and it will look amazing.

https://www.dyed-veneer.com/product-p/7424g.htm