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Yes, put some steel wool in a vessel of vinegar for several days, you will end up with an iron acetate solution. This will react with the tannin in oak (or any other high tannin wood) and darken it. I have read of people using it to darken woods, but I have only been able to get black (or really ugly color on low tannin woods). It will dry to a grayish color, but be totally black under finish (or FB oil). The color doesn’t really penetrate deeply; it will only go as far as the vinegar soaks in. I did the black fretboard by soaking it in a tray of the solution for a day then of course had some issues with movement. If you haven’t bound it yet, put a black layer between the binding and board so you can keep the solution off the binding. I made totally black veneer strips for purfling with this technique once. I put the strips in a capped PVC pipe filled with the solution for about a week, and was able to get full penetration. I’m not sure if it was needed, but I then soaked the strips in a baking soda solution in case I needed to neutralize the ph. Then I hung them up to dry.
Do you know what kind of oak you have? The banjo pictured on my thread was originally going to have a black board but (I think) it was white oak and would not soak up much of the solution so I did not get good penetration. I still wish I had done it in black.
TEST ON SCRAP!

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Ok cool, I'm going to test this out asap. It's white oak. One article I read said to make a strong black tea and coat the wood with that first. That adds even more tannin. Wonder how a good Cabernet Sav would do?

I really don't think you will need to add any tannins in, you just need to get the solution into the wood, which will be difficult with white oak. I ended up having great penetration near the fret slots where it could wick into the end grain and lackluster color everywhere else.

Remember it will take a few days of soaking before your steel wool/ vinegar solution will be ready.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

I am really enjoying this build thread and your use of super-salvaged materials. About the frets reacting with the oak - I think you would be safe as long as you don't use any water based glue to seat the frets in the slots.
If you want a darker finger board, you can try fuming it with ammonia. Get a pail or garbage can (clean) place a small dish of ammonia in the bottom and put the FB in, and put the lid on. If you try this DON'T do it in your house as the ammonia fumes are dangerous. You can place a few scraps of oak in as well to use as test pieces. After an hour or so take one out and wipe with paint thinner. This will show what it will look like with a finish. If it isn't dark enough, leave it longer, and re-test another piece. Because this is a reaction between the ammonia and the tannin in the wood, the colour goes fairly deep into the wood.
With white oak, the medulary rays will really pop, and look like Mission style furniture!

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

Alex, have you had luck with this using household amonia? I always thought you needed the high concentration stuff (anhydrous amonia or aqueous amonia or something like that [which is pretty darned dangerous to breath around]). For that reason, I have never tried this.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Brian, I have yet to try this. I had planned on it a few times, but it's pretty hard making an enclosure for the size of cabinetry that I do. I think that the household ammonia will work, but you would want to used a wide pan to maximize the amount of vapour being released, and change the ammonia as it will weaken as it evaporates. It will likely take longer, but it would definitely be safer than full strength ammonia.
I've cut a few QS red oak back and side sets that I hope to someday build with, and plan on fuming the box. I'll just make sure to test the top material and bindings first!

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

Interesting, ok so I have a few experiments to do this weekend, again thanks for the tips.

So it's been 24 hours with vinegar in a jar with steel wool and so far nothing is happening. So I looked at the bottle and it said it was diluted with water to 5% acid. Doh! I guess I need another bottle of vinegar. I do have some wood bleach and I wonder if that will work.

Another piece has been in the ammonia chamber for the same time and is starting to darken.

I just went through this a few weeks ago. I put a full pad of 0000 steel wool in a quart of Walmart vinegar and for 2 days nothing happened. Around day 3 I went in and the steel wool was no more except for the crud in the bottom and some stuff floating on top. A more acidic solution may work quicker. I read a post where someone had recommended Heinz brand, maybe it is stronger.

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Steve Smith
"Music is what feelings sound like"

The steel wool does not have to disappear, just give enough iron to the solution. If you see little bubbles forming, it is working. Some steel wool may have oil on it which will slow the process. I just used a gallon jug of dollar store vinegar and all is well, still works after years too.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Ok I read one article that said to boil the steel wool and vinegar and take it off the heat. The heat seems to be a catalyst for this reaction because it's been bubbling pretty good for hours.

Actually, the only reason they recommend boiling is because it will make your entire house smell like a salad for the next week. Its a cruel practical joke. You have been warned.

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http://www.CostaGuitars.com
PMoMC

Hahaha yes maybe so. Mmmmmm Salad... I should cook up some bacon too, why not?

What sort of rubber are you using here? I'm looking for some but don't know what sort to get or where to get it. Does it have to be stretchy?

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"I am always doing that which I cannot do, in order that I may learn how to do it."
Pablo Picasso

https://www.facebook.com/FenskeGuitars

That's a mix of a car/truck tire tube cut into one long strip that's broken many times over the years, and bicycle tire tubes that I've collected over the years. I ride bikes so instead of patching tubes when I flat I just tie them onto my strip and buy a new tube. If you have a bike shop near by they may have a bunch of popped tubes. I find the mountain bike one's to be the best as they are wider and stronger. Tie them together with a square knot.

Thanks

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"I am always doing that which I cannot do, in order that I may learn how to do it."
Pablo Picasso

https://www.facebook.com/FenskeGuitars

Ok where was I? Oh yeah! I finally got that steel wool to dissolve by the boiling method so I did a scrap test with that and also the ammonia fuming.

The fat piece is the fumed test and the square rod was dipped in the FE rich solution. The ammonia didn't quite get dark enough but the other stuff looks great


Then got to building and shaping the neck. It's fun to use carpenter tools on a guitar


Clamping up the fret board


Carving the neck with a spoke shave


I went with the V-Shape profile on the neck as in the Bruno plans, I like the feel of it


I already had my fret board binding done so I taped it off and shellacked the maple binding to protect from the FE soak. So I first raise the grain with some tannin rich black tea


Then just brush on the iron solution and voila! Ebonized oak. I was really impressed with how this worked. This is after 4 coats. The bridge in the back ground is going to be remade. I need to make it a bit bigger.

Have you tried sanding/polishing that black fretboard yet? I have one made of Bastogne walnut that I want to do that way so figured I'd piggyback on your work since you're so far ahead of me

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Steve Smith
"Music is what feelings sound like"

Steve yes I have sanded it and it doesn't go too deep. You would want to pretty much have the fretboard fully prepped and raise the grain real good till it raises no more. It won't rub off on your fingers, it's really not like a stain but more like a chemical reaction. I have some minwax ebony stain which by itself doesn't really do anything but I may try it out as a sort of sealer and to see if it darkens it a bit more.

That's pretty much what I expected and that's ok. Are you going to put some oil on it? Bryan had recommended that and seems like a reasonable idea but I haven't given any thought to what kind of oil I might use.

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Steve Smith
"Music is what feelings sound like"

Steve, I now realize I was vague about the oil (sorry about that). I meant fretboard oil as opposed to any kind of film building oil finish (though that would also have the same effect but perhaps not ideal for a fretboard). Whatever you oil your boards with would be fine. If you don't usually oil them, then any mineral oil product would work. I use an Olde English product. I think it is for hiding scratches as it has some dye in it (I use the light wood formula). I'm pretty sure it is just mineral oil and dye. In the past I have used tung oil on an "ebonized" oak board and that also worked to make the silvery grey blue dry oak a nice black.

I'm glad you guys are doing this on fretboards. I was trying to decide what to use as a fretboard on my next project. I was thinking of ebonizing some osage orange but wanted to bind it. I like to work on the surface after the binding is on. This will give me some ideas on how to do this. . .

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Hey Bryan, good to know you're just using a mineral type oil on the fretboards - I was wondering. I don't like to put anything else on them.

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Steve Smith
"Music is what feelings sound like"

I've been pleased with the results of using walnut oil on ebony, it buffs out to a nice gloss. Ebony buffs out to a nice gloss without the walnut oil, it's just a little easier with it. I suspect it would work well on oak, unless the pores weren't filled.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

I'll add walnut oil to my list of suspects as well. After all, mine is a walnut fret board so why not

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Steve Smith
"Music is what feelings sound like"

Rodger I did not fill the pours. I was thinking about it but I don't want gunk in the fret slots either. The pours on this old white oak are actually not too deep but I guess the oil would never fill..

I put two coats of Minwax ebony stain on it thinking it would darken and seal it, I think I will leave it at that but as always am open to suggestions.