# Help: dark finish for red oak...



## mofo83 (Oct 4, 2011)

Hello.

I am making a dining table and bench out of red oak. I would like the finish to be quite dark, sort of like this: 

http://www.victorianfloorfinishing.com/images/stainSamples/darkWalnut.jpg 

However, if possible, I'd like there to be less of a contrast between the different areas of the grain (less of a "zebra" effect, as my wife would say.) More of a _uniformly_ dark color, yet not totally obscuring the character of the wood. Then, I will be using wipe-on poly as the clear coat. 

My first thought was to just use a dark stain, but that didn't achieve a nearly dark enough finish, and it created a really extreme contrast between the different areas of the grain. 

Then, I tried using a dark aniline dye, followed by dark stain. The dye didn't take evenly across all the different _areas _of grain, however (some of the grain is water repellent?) So, even though this achieved the desired darkness, it ended up looking sort of muddied/uneven, and definitely obscured the beauty of the wood. 

Finally, I tried using a dark stain, followed up by a coat of tinted shellac (used the aniline dye). This has worked the best so far, because it's fairly even darkness, and I can still enjoy the beauty of the wood. However, I find the shellac hard to apply evenly, plus the dark-brown dye is tinting the shellac a reddish color instead of just dark brown. 

Is there some "easier" way to achieve the finish I'm describing, that I don't know of? I'm pretty new to woodwork. 

Thanks!

PS: I realize there was probably a better choice of wood if I'm looking for a uniformly dark finish, but I'm set on oak now!


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## chemmy (Dec 13, 2011)

normal procedure would be to use an NGR [non grain raising} dye/stain to put down first to create a uniform base color of the lightest color, then seal and apply a solvent/oil base stain such as van **** brown and burnt umber to get the rest of the color. Though you can apply the stain right over the NGR once dry, "if" the surface is uniformly smooth and even, you most likely will find it is not, and the stain will have dark and light areas. you need to make samples always before actually doing it on the required project surface ok? Make "samples' part of your finishing schedule, and you will rarely have to concern yourself with how the project itself will then turn out. :yes:


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## mofo83 (Oct 4, 2011)

Thanks chemmy for the quick reply. 

First - yes, I have been testing all these finishes on small test pieces, not on the final project!

Regarding the dye, my issue is (like you mention) that it does not look even across all areas of the grain. Right after applying, it looks even, but after drying, there are little "flecks" where NO dye "soaks in," some areas where it is almost black, and some areas where it looks brown. (Maybe I can take a picture later.) Applying the stain evens out the look somewhat, but it also gives the finish an overall muddied, almost oily appearance. Much of the character of the wood is obscured, too. 

So are you saying that doing a "sealing" step after the dying step will help with this? Wouldn't it just seal in the uneven looking dye!?

Thanks!


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## chemmy (Dec 13, 2011)

mofo83 said:


> Thanks chemmy for the quick reply.
> 
> First - yes, I have been testing all these finishes on small test pieces, not on the final project!
> 
> ...


No i'm saying That it is mainly a surface dye, one that does not saturate the surface which gives you, [if you apply the dye by gun as a light coat uniformly as the factories do], an even base color so that then, when it is sealed, the color will look very uniform, then, lightly sand 320, and apply your pigment stain. the sealer acts a a thicker version of wood conditioner in the sense, not allowing the stain to soak into the softer portions of the wood as it would do if applying it directly. If necessary, even 2 coats of sealer can be applied [sanded in between] if your still having problems with the uniformity. But the "real trick" is to apply the dye in such away as to not wet the surface to any degree so that it dries immediately and stays more on the surface, thus - giving you a uniform color appearance. If the dye is applied by brush or rag, the softer or less smooth areas will absorb more and show as darker blotchier areas. i have confidence that with practice you will do this. :yes:


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## cabinetman (Jul 5, 2007)

mofo83 said:


> So are you saying that doing a "sealing" step after the dying step will help with this? Wouldn't it just seal in the uneven looking dye!?
> 
> Thanks!


If your dye was waterbased, try the same color in alcohol (methanol), and see which you like better. After it's dyed and dry, take your sample and spray a sanding sealer. You should see some difference right away...that muddiness should clear up. Then if you are spraying lacquer do a topcoat. Then evaluate your finish.










 







.


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## mofo83 (Oct 4, 2011)

I don't have a sprayer (and won't be purchasing one), but it sounds like maybe if I add the Transtint to an alcohol base, it might help it dry more evenly. As I have been using it (water-based, applied by brush) it is definitely drying very slowly, and soaking more into some areas and not at all into others, like you say. 

So, the process would go like this: alcohol-based aniline dye, sanding sealer, sand lightly, oil-based stain, wipe-on poly? 

Thanks, I'll try it.


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## chemmy (Dec 13, 2011)

mofo83 said:


> I don't have a sprayer (and won't be purchasing one), but it sounds like maybe if I add the Transtint to an alcohol base, it might help it dry more evenly. As I have been using it (water-based, applied by brush) it is definitely drying very slowly, and soaking more into some areas and not at all into others, like you say.
> 
> So, the process would go like this: alcohol-based aniline dye, sanding sealer, sand lightly, oil-based stain, wipe-on poly?
> 
> Thanks, I'll try it.


No, if your using poly, no sanding sealer, just poly as the sealer. and you cant use a pigment wiping stain if your going to use a brush application. if that is your only choice, then by a spray can or more of spray poly to do the sealing and coatings with. Once you've spray sealed the pigment stain a couple times, then, if for some god awful unknown reason, you want to go back to brushing, be my guest. lol


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## mofo83 (Oct 4, 2011)

Ha, okay, that makes sense. I suppose when I was wiping on the stain, I was probably wiping around the surface dye and making it look even more uneven/muddied. 

I did buy a can of spray sealer so I'll try that again...

Thanks


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## chemmy (Dec 13, 2011)

mofo83 said:


> Ha, okay, that makes sense. I suppose when I was wiping on the stain, I was probably wiping around the surface dye and making it look even more uneven/muddied.
> 
> I did buy a can of spray sealer so I'll try that again...
> 
> Thanks


hopefully by "sealer" you mean poly lol:yes:

And no the pigmnet stain would not lift or take up the dye.


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## mofo83 (Oct 4, 2011)

Ahh.. hmm.. it might be spray shellac, now that I think of it. I can pick up a can of spray poly though. 

Thanks


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## mofo83 (Oct 4, 2011)

On a side note... anything wrong with using a tinted Sealcoat (shellac sanding sealer) as a way to add some translucent color on top of an oil stain, then covering with a wipe-on poly?

I may very well end up liking the look of this type of finish better than the dark dye anyways...

Thanks


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## chemmy (Dec 13, 2011)

mofo83 said:


> On a side note... anything wrong with using a tinted Sealcoat (lacquer sanding sealer) as a way to add some translucent color on top of an oil stain, then covering with a wipe-on poly?
> 
> I may very well end up liking the look of this type of finish better than the dark dye anyways...
> 
> Thanks


Your not understanding the problem, poly will not adhere to lacquer products well. and this especially holds true in your case where your doing top surfaces with daily use and wear. always stay with the same type of coating if possible. Shellac is out of the question because of poor reisitance of heat the top may be subject to. so bite the bullet and buy some cans of poly lol. If an oil tint is used before the top coat in minute quantity, you can do it that way however.


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## mofo83 (Oct 4, 2011)

Ah yes, I'm sorry, I meant Shellac sanding sealer, not lacquer. Sounds like neither will work though? Would the poor resistance to heat matter if I covered the tinted shellac with multiple top coats of poly? I never meant the shellac sanding sealer to be the final top coat, just an added layer of tinted color...

I was interested in the tinted _shellac_ because the dye I have can be added to the shellac, but it can't be added to an oil-based poly (which is what I was going to use.)
But the dye could be added to a water-based poly, I think, if that was something I wanted to mess with and try out. 

All options are on the table! (No pun intended.)

Thanks, sorry for the confusion.


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## chemmy (Dec 13, 2011)

mofo83 said:


> Ah yes, I'm sorry, I meant Shellac sanding sealer, not lacquer. Sounds like neither will work though? Would the poor resistance to heat matter if I covered the tinted shellac with multiple top coats of poly? I never meant the shellac sanding sealer to be the final top coat, just an added layer of tinted color...
> 
> I was interested in the tinted _shellac_ because the dye I have can be added to the shellac, but it can't be added to an oil-based poly (which is what I was going to use.)
> But the dye could be added to a water-based poly, I think, if that was something I wanted to mess with and try out.
> ...


yes, if you wanted to go with an aqeous based poly it would work, but then you would have to go with a aqeous stain also instead of the oil stain for best innnercoat adhesion, really it would be simpler if you just add a little milkyness to your poly your using for a first coat over the dye and then a regular coat on top of it and then glaze on the oil color you prefer, but do what you will. just giving advice.


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## mofo83 (Oct 4, 2011)

Yes, if I go with water-based I'll stick with water-based! 

Thanks


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## chemmy (Dec 13, 2011)

mofo83 said:


> Yes, if I go with water-based I'll stick with water-based!
> 
> Thanks


 ok good luck


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## jkline805 (Nov 14, 2011)

one thing I have done recently on Birch plywood was to spray (I know you said you didnt have one) water based stain on the project and completely cover the wood until the stain is basically opaque. Then, as it dries and absorbs, some of the grain shows through, but you end up with a pretty even color. I can show a picture to show you what the results were.

then I topcoat with water based poly.


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## mofo83 (Oct 4, 2011)

That sounds interesting, jkline. I haven't tried a water-based stain yet. Maybe I'll check it out.

This is basically my first "real" project, so I'm learning about finishing as I go... 

Thanks!


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## mofo83 (Oct 4, 2011)

Okay, one last time, just so I have it straight... will this procedure create (in theory) a nice, somewhat uniform, dark brown finish? (Keeping in mind that a paint sprayer is not an option): 

1. Sand up to around 180 or so. Clean surface of all dust. 
2. Apply water/alcohol-based dark brown aniline dye. Let dry.*
3. Spray (from can) with oil-based poly. Let dry. Sand very lightly. 
4. Apply regular pigment stain (e.g., Minwax Wood Finish) and wipe off excess. Let dry. 
5. Apply wipe-on poly. Let dry. Repeat for multiple coats. 

*(One other thing: I have read that misting the wood with water before dyeing can help even out the application. When I do this 'pre-mist,' it raises the grain almost immediately; can I sand lightly while the wood is still wet, to knock down this raised grain a bit? Then clean off the wood surface, and dye it immediately?)

Thanks!


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## chemmy (Dec 13, 2011)

mofo83 said:


> Okay, one last time, just so I have it straight... will this procedure create (in theory) a nice, somewhat uniform, dark brown finish? (Keeping in mind that a paint sprayer is not an option):
> 
> 1. Sand up to around 180 or so. Clean surface of all dust.
> 2. Apply water/alcohol-based dark brown aniline dye. Let dry.*
> ...


Do "samples", you can adjust from there, once you see the results ok?


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## mofo83 (Oct 4, 2011)

Yup, it's sample time. 

Thanks again.


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## cabinetman (Jul 5, 2007)

mofo83 said:


> Okay, one last time, just so I have it straight... will this procedure create (in theory) a nice, somewhat uniform, dark brown finish? (Keeping in mind that a paint sprayer is not an option):
> 
> 1. Sand up to around 180 or so. Clean surface of all dust.
> 2. Apply water/alcohol-based dark brown aniline dye. Let dry.*
> ...


Doing #3 could conceivably seal the wood preventing any absorption of a further application of stain or dye. At the time the water based has dried, the color may be just right. At that time another color of WB can be added. When dry, an oil base stain can be added.

*** I've tried the 'wetting' and found it less than worthwhile, as does wetting to raise the grain. Any raised grain derived from using waterbase dye will be dressed down with a light sanding between topcoats.

I'm just describing what I've done that has worked for me.











 







.


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## mofo83 (Oct 4, 2011)

In response to your post Cabinetman, I _have_ noticed that my samples seem to turn out _worse_ when I use a sanding sealer or poly coat before I apply the stain/glaze layer. Plus, the stain seems to have a harder time then filling the undyed pores, for some reason. 

I feel like some of the problem is that even when I _spray_ the sealing coat, it is mixing with some of the dye that has dried on the SURFACE of the wood, making a muddier/splotchier looking finish. *After it totally dries, should I wipe down the dyed surface with water to remove any dye that is just sitting on the surface? *

*Any thoughts about using a gel stain directly over the dye?* I would think this might be ideal, because it will sit in the pores (which I'm having trouble dyeing) without making the more darkly dyed sections much darker. I'll test it. 

BTW, *here are two posts I've found on other sites that deal with this very issue.* Their dyed samples look exactly like mine do! 

http://www.woodweb.com/knowledge_base/Enhancing_Oak_Grain.html

http://forum.canadianwoodworking.com/showthread.php?25046-Aniline-Dye-problem-with-Red-Oak – you have to register to see the images 

Thanks again.


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## TylerJones (Dec 4, 2011)

Sorry to offer a solution drastically different from your current line of thought but... Have you thought of ammonia fuming the piece? It's super easy and will give you a uniform brown, Works very well on red oak. Then just topcoat.


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## chemmy (Dec 13, 2011)

Good thought Tyler, i would also suggest you give the surface a coat of 1 oz to 1 qt. of distilled water and tannic acid, so as to even out any variances from board to board from various lumber used, as to uniforming the final color acheived on all pieces. 

I will leave it to Tyler to give you the info on chamber construction and or direct use of the ammonia process, as he may be or is using. :thumbsup:


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## mofo83 (Oct 4, 2011)

Wow, I just did a Google image search for "ammonia fumed oak" and I _really_ like this look. It might be _exactly _what I'm looking for...

Seems like you just have to build a little "tent" out of plastic sheeting and some sort of frame, and place your wood project inside with a saucer(s) of ammonia for 24+ hours? 

Any tips for building the chamber? And I can use any protective top coat I'd like? 

Since this is a glued tabletop, I'm guessing I would have to first glue and completely sand the top first, then place in the chamber? 

Chemmy: where would I find tannic acid? 

Thanks!


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## chemmy (Dec 13, 2011)

mofo83 said:


> Wow, I just did a Google image search for "ammonia fumed oak" and I _really_ like this look. It might be _exactly _what I'm looking for...
> 
> Seems like you just have to build a little "tent" out of plastic sheeting and some sort of frame, and place your wood project inside with a saucer(s) of ammonia for 24+ hours?
> 
> ...


http://www.woodfinishingenterprises.com/dyes.html

I cannot emphasize enough on being careful with the fumes of ammonia, they will knock you on your A**, as well as other things.:yes:

If by chance, TylerJones does not respond back or others, I'll get back with advice on the other.

PS: yes, you can use any finish you like, once the ammonia has completely evaporated and is bone dry, you can proceed with the finish of choice.


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## mofo83 (Oct 4, 2011)

Success!

I took two small sample pieces of my oak and put them in a plastic box, with some weak household ammonia. About 24 hours later, and they already look pretty great. We'd still like our table/bench a little darker though, so I just got some stronger (10%) ammonia from Ace Hardware and put that in there. I'm guessing with this stinkier stuff it will be perfect very soon.

Here's a pic of the results so far. The thin piece in the middle and the unfinished bench top underneath are the "before" color. 

Thanks again for all the help!


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## chemmy (Dec 13, 2011)

mofo83 said:


> Success!
> 
> I took two small sample pieces of my oak and put them in a plastic box, with some weak household ammonia. About 24 hours later, and they already look pretty great. We'd still like our table/bench a little darker though, so I just got some stronger (10%) ammonia from Ace Hardware and put that in there. I'm guessing with this stinkier stuff it will be perfect very soon.
> 
> ...


Looking good mofo, If you can though remember to try and use the FS on your actual project so the variance of colors will not be great ok?:yes:


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## mofo83 (Oct 4, 2011)

When you say "FS," is that the same as Tannic Acid (which you suggested before)? 

Also, some people online were saying that a "tea wash" could also help in a way similar to the tannic acid? (I guess because tea has tannins...?) Would that be an option too? 

One other thing - I have had so much trouble with this wood absorbing the water-based dye uniformly (certain pores will not absorb ANYTHING) is this tannic acid and water mix going to give me the same issue - and actually cause the finish to look _less _uniform, from one grain area to the next? 

Thanks again.


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## chemmy (Dec 13, 2011)

mofo83 said:


> When you say "FS," is that the same as Tannic Acid (which you suggested before)?
> 
> Also, some people online were saying that a "tea wash" could also help in a way similar to the tannic acid? (I guess because tea has tannins...?) Would that be an option too?
> 
> ...


Good questions, first let me apologize, the FS was a mistake, yes i meant the TA instead, forgive me. there is a difference between tannins and tannic acid, i wont go into detail but no the tannins wont do what the acid will. all trees have varying amounts of tannic acid, oaks have much more than most. But the amount from tree to tree and area grown, will vary. The idea or principle is to use the TA to uniform the varying contents from board to board out so the [in this case] fuming will end up giving you a more uniform all over brown. You don't have to use it but you may probably find that there is variance and since your not liking variances from your writings is why i suggested it's use ok?

Don't be concerned with the pores when using the ammonia, it is able to color the hard lignin it is made up of, unlike the water dye. water just rolls off the lignin walls doesn't penetrate, therefore leaving the interior lining its natural color. That's why pigmented stains are normally used over the dye or at least a colored grain filler. and no, the water/TA mix will not do anything but make more tannic material available for the alkaline ammonia to work on, nothing more ok?


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## mofo83 (Oct 4, 2011)

Okay, thanks. I just wondered if because the TA mix will "soak" into certain areas more than others, if those areas would end up much darker. 

One more question: how much tannic acid would I need? I would need enough for a dining table and a bench. Put another way, what ratio would you mix the water to tannic acid? 

Thanks again.


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## chemmy (Dec 13, 2011)

mofo83 said:


> Okay, thanks. I just wondered if because the TA mix will "soak" into certain areas more than others, if those areas would end up much darker.
> 
> One more question: how much tannic acid would I need? I would need enough for a dining table and a bench. Put another way, what ratio would you mix the water to tannic acid?
> 
> Thanks again.


well.... if you use a saturated solution of TA, meaning one which the TA is added to the water till it can hold no more and the extra sinks to the bottom undisolved, i would say purchase 8 oz. even though it will most likely not take that much, but the left over will be good indefinitely if stored in a dry cool area. This will give you the darkest reaction. 

Typically, in factories, a 1-2 oz. per gallon ratio is used.

In your case if your samples show that the second ratio will give you what you want and is dark enough, then i would make up no more than a quart of the 1-2 oz ratio in distilled water ok

If you desire darker color, then the saturated solution and of course and both more time in the ammonia chamber.

A quart of the mixture should be more than enough for1 top and bench, it's a good single application technique and most aqeous solutions cover more than 30 - 60 sq, ft. per qt.


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## mofo83 (Oct 4, 2011)

Sorry, one more question chemmy:

Since this is an aqueous solution, it will raise the grain of the oak when I apply it. If I then sand down the raised grain (lightly), will I be sanding away the tannic acid I just applied in certain areas? 

Would I instead have to raise the grain with plain water, sand, then apply the tannic acid? 

Thanks


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## chemmy (Dec 13, 2011)

Yes.


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## Carlo Bartolini (Aug 30, 2011)

You can buy tannin from Kremer or Wood Finishing Enterprises

http://kremerpigments.com/shopus/index.php?cat=0302&lang=ENG&product=94500

http://www.woodfinishingenterprises.com/dyes.html


The "tea" comment might have been me, it is used by some violin makers for the darkening of maple /spruce along with sun tanning, link below.

http://www.maestronet.com/forum/index.php?showtopic=323034&view=findpost&p=491231

if you'd like to see what it looks like (very beautiful in my eyes):thumbsup:

http://www.maestronet.com/forum/index.php?showtopic=323743


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## mofo83 (Oct 4, 2011)

An update: 

I received my tannic acid, mixed a weakish 1 tbs/pint solution, and wiped down a sample piece of the oak with it. I then fumed it for about 36 hours with a 10% ammonia solution. Finally, I applied around 5 coats of wipe-on poly, sanding very lightly in between.

It looks very nice, and gives it a yellowish/brown color, and an almost 'weathered' look. I can maybe post a picture later. I think for the final project, I'll leave it in for another 12 hours or so to darken the color more. The tannic acid does seem to help it get darker faster. 

However, I have noticed that the tannic acid almost made the color _more_ uneven, because the areas where the solution 'soaked in' the most are darkest, and the areas that didn't soak up any of the solution (the lingin?) stay lighter. I'm afraid if I increase the strength of the solution, this contrast will just be even more noticeable. 

Thanks again for the help. I should be fuming the actual piece soon...


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## chemmy (Dec 13, 2011)

mofo83 said:


> An update:
> 
> I received my tannic acid, mixed a weakish 1 tbs/pint solution, and wiped down a sample piece of the oak with it. I then fumed it for about 36 hours with a 10% ammonia solution. Finally, I applied around 5 coats of wipe-on poly, sanding very lightly in between.
> 
> ...


Hi mofo, yes post a pic [close up] of where your at now ok? sounds like you may need the saturated solution i first reccomended but i want to see the pores [lignin] areas first to determine whats happeinig ok? 

another thing is factories used 28% ammonia not 5/10% ok.

Have you coated your first samples yet? the first 2 pics? may i see them also? if not coat half of each with your finish and leave the other half uncoated ok?


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## mofo83 (Oct 4, 2011)

I think I'm going to try one more sample before I take up your time troubleshooting the finish.

I'll use the saturated solution and fume the wood longer this time. 

Then I'll finish one half and leave the other half unfinished. 

Thanks again.


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## mofo83 (Oct 4, 2011)

So, I've been working on the bench and have tried the fuming again on a few samples. Here's a pic of two different tries. The one on the left was coated with the saturated tannic acid solution and fumed for around 3.5 days. The one on the right had no solution applied, fumed for around 4 days. Then, I put one layer of poly on each, leaving an uncovered "control" section in the middle without poly. 

It's sorta hard to tell from the pic, but the darker one (w/ solution) has much more of a contrast between the different dark/light areas of the grain. It doesn't look "right," because the "lignin"(?) didn't soak up any of the solution, I think. I'm wondering if there is a way to give it a more uniform brown color across all parts of the wood?

The lighter sample, on the right, is satisfactorily uniform, but it's too yellow/light. I may try fuming the wood even longer - like a week. Maybe that will darken/brown it more. But, I'm assuming there's a point where all the tannic acid has been reacted with, and it won't get any darker? 

I just applied a little gel stain to one section of these samples and some danish oil to another section, and it seems like the danish oil might help... darkens the areas that didn't soak up the tannic acid solution on the darker sample, and generally darkens the untreated, lighter sample. But there's still some unevenness because the lignin doesn't even like to be penetrated by the oil finishes!

Thanks


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## chemmy (Dec 13, 2011)

mofo83 said:


> So, I've been working on the bench and have tried the fuming again on a few samples. Here's a pic of two different tries. The one on the left was coated with the saturated tannic acid solution and fumed for around 3.5 days. The one on the right had no solution applied, fumed for around 4 days. Then, I put one layer of poly on each, leaving an uncovered "control" section in the middle without poly.
> 
> It's sorta hard to tell from the pic, but the darker one (w/ solution) has much more of a contrast between the different dark/light areas of the grain. It doesn't look "right," because the "lignin"(?) didn't soak up any of the solution, I think. I'm wondering if there is a way to give it a more uniform brown color across all parts of the wood?
> 
> ...


If you had 26-28% ammonia it would take less time and darken more, hard to do with weak ammonia. 

Next test - dissolve the TA in alcohol - saturated solution, add 5% shellac, [zinnser sealcoat] apply with a stiff bristle brush, wipe it with a circular motion to get it down into the cell wall areas, let dry over night, the nfume it. the shellac will be so thin it will allow it to do 2 things, cling to the cell walls and allow the fumes to penetrate the rest. get back with results and pics please, outside oth that its looking good.


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## mofo83 (Oct 4, 2011)

Hey Chemmy,

Thanks again for all the help.

Actually though, my lack of patience (or maybe the excitment of actually fininshing a project!) got the best of me and I went ahead and fumed my bench with no TA solution whatsoever. 

But, I did some new things to help darken the results, and it seemed to help a lot:

1. Use more ammonia. Instead of one small dish, I used one large dish plus two small ones. Clearly created a lot more stink. 

2. Aim some heat toward the fuming tent with a space heater. I read that a warmer temp could possibly result in a darker brown, and make the reaction happen faster.

3. Replace the ammonia with fresh stuff half way through the 4-day fuming process. 

The result was a nice grayish chocolate color, which my wife actually really liked (more than the reddish brown achieved with the TA.) 

Now there is a new problem (which I actually asked about in a new thread) - is there a finish that WON'T darken the fumed wood!? I know, I'm a flip-flopper, but we both like this grayish chocolate color and the wipe-on poly REALLY darkens it a lot (I tested.) Not sure what would deliver the protection needed for a table, without penetrating and darkening... water-based poly?

Thanks again!


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## Carlo Bartolini (Aug 30, 2011)

it seems you will now need a little oxalic acid to lighten it back again.....


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## mofo83 (Oct 4, 2011)

I mean, it's not that big of a deal, really. 

If there is no such thing as a protective coat that can preserve this grayish/chocolaty look, the dark brown will be okay. 

I was just curious...

Thanks!


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## TylerJones (Dec 4, 2011)

Waterbased poly will darken only a little and will protect well. Waterbased vinyl will make it look exactly like it does now. Protection is a little less.


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## chemmy (Dec 13, 2011)

mofo83 said:


> Hey Chemmy,
> 
> Thanks again for all the help.
> 
> ...


I should have told you heating the ammonia up would quicken the process, in fact you can use a can of Sterno or gelled alcohol as a heater - make a wood square about twice the size of your dish or whatever sink 43 nails at an angle that will support the ammonia bowl, make as many as wanted! then fill your bowls with ammonia half way and first light the gel and while holding your breath, place the bowls on the nails then close up the tent. keep a close eye on the work !!!

No, there is no coating that will not darken the look to one degree or the other. I've wanted that possibility many times in my career especially with driftwood, lol. about the closest I've come is with waxes of my own making, but that would be scarce/ negligable protection for a dining table top.


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## Carlo Bartolini (Aug 30, 2011)

Chemmy, would a very dilute application of oxalic acid do the trick for him????

thanks me friend


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## chemmy (Dec 13, 2011)

Carlo Bartolini said:


> Chemmy, would a very dilute application of oxalic acid do the trick for him????
> 
> thanks me friend


Hi Carlo, The use of oxalic acid for bleaching uniformly is difficult, though it has a some bleaching action for sure i prefer to use it only when doing antiques or old furniture where uniformity is not so big an issue. 

It's main use is as a chelating agent for the removal of metallic salts mostly iron stains [grey/ black stains] it is able to pick up and hold on to the ferric ions thus eliminating them. as a chelate it is able to grab onto metal ions to form what is know as a "chelating ring", [ a structured compound forming co-ordinate bonds that contain the metal ions] When dry it is washed off and neutralized and the piece has no more of those types of stains, though it may have other types, lol. Iron-gall inks will be removed by it also. Indian inks - NO! for India inks you would need fuming grade picric acid [dangerous stuff!!], or concentrated bleaching powder, [a mixture of calcium chloride, calcium hydroxide, and calcium hypochorite] when this is reacted with a 1-1 mixture of hydrochloric acid, by use of a pointed glass stirring rod, directly on the ink stain will remove most others. 

I know for what ever reason your fond of oxalic, but personally i use it very little, though for sure it is a necessary bullet in the wood finishers gun. lol :yes:


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