Darkening oak Questions

Re: Darkening oak Questions

Dick Coers

Vinegar and steel wool will turn it very dark, almost black.

Re: Darkening oak Questions

Kevin French

It will turn it black but it can be sanded lighter with little effort

My View

Mark Mandell - Gone Round In New Jersey

1. Fuming is dangerous, and then you've got this highly toxic stuff left to deal with.

2. Wool and vinegar (a/o walnut shells or other "natural" formulas) have not impressed me as giving controllable results.

My preference is to use an NGR dye stain to get the even ground color more characteristic of an age patina, then work over that with a pigmented oil stain. Then top coat with a satin finish. Rubbing in the oil stain with let you create "wear" on edges. How and how much you distress the new surfaces is up to your personal taste. Can't say I've seen distressing that could pass for age/use marks.

Re: My View

Paul in NJ

Barry,

I have had good success using household plain ammonia (no scent). I have tented furniture in a large plastic bag, laying saucers of ammonia to fume the piece. I do this outside when weather is warm. While household ammonia could hurt your eyes or respiratory system if you snort some, I don't think it is particularly dangerous like the anhydrous stuff. It has been used in homes for cleaning forever.You can dispose of it on your lawn, it is a nitrogen fertilizer. It also does a great job cleaning shellac and Zinser from your brushes.

The ammonia gives some color that penetrates into the wood a fair extant. The color is kind of cool so I follow with Transtint Mission Brown dye. Varnish or shellac on top. Do some small test pieces with scrap before you commit. You might even like the Mission Brown without fuming. One of these days I am going to try the anhydrous stuff.

Paul in NJ

hazard

Bill Tindall, E.Tn.

properly tented and in a ventilated space the human exposure will be less than cleaning windows inside the car with Windex, and much less than shoveling out the hen house (birds poop urea which coverts to ammonia when wet).

Ammonia triggers a response that initiates retreat from any harmful concentration. I don't regard it as any more hazard than anything I use for finishing.

Do wear safety glasses as high concentration will damage eyes.

The color it generates with mahogany is more fleeting with UV exposure than the color from premetalized wood dye.

Re: Darkening oak Questions

Jim Dillon

Barry, you didn't say how dark your son and DIL want for the table. I've used the same setup as Paul in NJ, i.e. regular ammonia on QSWO in a plastic tent and it works just fine. As it is not nearly as strong as anhydrous ammonia, it takes a lot longer; I replace the ammonia from time-to-time to provide fresh ammonia. Ambient temperature affects the process as well. The result is a cool blue-gray oak that I then apply T&T varnish oil. The result is a medium brown that I am pleased with for A&C-style furniture. I have no experience with other approaches, but suggest experimenting on scrap QSWO. Jim

Re: hazard

Dick Coers

Working with anhydrous buggies on the farm put the fear in me. Of course it’s under pressure in that case, but I don’t want to come close to it again. From what I read, even Stickley used dyes or stains due to the color variation caused by sapwood to heartwood.

Couple things...

Ellis Walentine

Plenty of good replies here already. I would add that anhydrous ammonia (sold as 28% or blueprint ammonia) is quicker than household (5%) ammonia, and that the longer you expose the wood to the fumes, the deeper the color penetration. You really need to be careful with the anhydrous stuff. I had an employee once who got a good whiff and he was gasping for breath.

One thing about fuming: it turns the medullary rays dark as well as the spring and summer wood, so if the look you want is with dramatic, lighter-colored rays against a brown background, I would suggest staining with some combination of dyes and pigment stains, even varying the order of application to see the effects. As with all coloring and finishing trials, you need to prepare a few samples of the same wood and experiment with materials and techniques until you get something you like, before you work on the real deal.

Ellis

The best reason for dye

John in NM

is the color variation of more traditional methods that react with chemicals in the wood. Concentrations of those vary, so the color will vary.

Household ammonia is not dangerous compared to solvents that most of us use on a regular basis. Those of use without sensitive skin do not notice any adverse reaction to the low concentration found in consumer grades of ammonia. Splash protection is wise as it will irritate eyes and sinuses.

Industrial ammonia is a whole other question. I used to use a dilute version of it in blue line copy machines - it was only a few times stronger than household. Catching a strong wiff of that while changing bottles was like getting socked in the nose. Can't even imagine working with the real anhydrous stuff!

The Toxic Stuff

Mark Mandell - Gone Round In New Jersey

I referred to was the "industrial grade" rather than the rather weak household dilution for window cleaner that takes so long to use. FAGEDUBOUDAT foitalizer anhydrus stuff!!

Re: Darkening oak Questions

Bob Lang

If you want to experiment with coloring by chemical reaction, don't do it if you're trying to match (or come close) to something else. You just won't have the degree of control you have with other methods. With experience you can judge how far to go with each step, but it won't look like what you want until the end.

Blueprint ammonia can be handled safely, but caution is advised. I wear goggles, good gloves and a respirator, have the tent and dish ready before opening the jug. Beyond the safety precautions there are a couple of issues:

Amount of tannic acid in each piece of wood determines how much of a reaction you get. This will vary, and sapwood won't turn color at all. This kind of thing can be corrected with careful application of aniline dye at the end.

The color from fuming won't look right until you apply a finish. It should look like you ruined it, but a wash coat of amber or garnet shellac makes the magic happen and you'll have a nice warm brown.

Vinegar and iron can be a crap shoot. Washing with strong tea before application can help to get you to a strong black, but you might end up with purple.

Here's my easy, fool-resistant recipe. Get a good oil-based dye stain. I can't tell you which brand because every time in the past that I have publicly recommended a specific stain the manufacturer either changes the name or the formula or gets bought out by vulture capitalists.

Find an old timer at the paint store who remembers what "Special Walnut" looked like. Let that dry for a day or two and follow with a coat of one of the "Walnut" flavors of Danish Oil. These two will give an even color on both the flakes and the surrounding wood. If you're after an authentic look you do not want the figure to "pop", you want it subdued. Give the oil a day or two to dry and coat with shellac. Amber or garnet will warm up the color. After the shellac, apply your go to finish.

Plan B is to color with aniline dye. Lockwood has a "fumed oak" in light, med and dark but you can control the intensity with the amount of solvent you use to dissolve the dye. To my eye this comes closest to a fumed finish but gives you good control of the outcome.

Bob Lang

Anhydrous ammonia confusion

Bill Tindall, E.Tn.

There seems to be some misunderstanding about ammonia. Anhydrous is just that, liquefied pure ammonia, NH3, held under pressure to keep it a liquid. Release the pressure and it will instantly turn to a gas cloud. Farmers, refrigeration repair workers and chemists might encounter it but woodworkers should never deal with it. I don't see how it could be effectively used to color wood because I don't see how its concentration could be controlled in the "tent", as well as a host of other storage and delivery problems.

Ammonia dissolves readily in water to make ammonia solutions. Various concentrations are available. The "lab" grade is about 30% ammonia in water and "household grade" a tenth that.

The amount of ammonia in the air above an ammonia solution is proportional to the concentration in solution. This relationship puts an upper limit on how much ammonia you can be exposed to when dealing with solutions, while the amount is up to 100% with anhydrous ammonia. The relation also enables the concentration in the tent to be controlled to some extent if the tent is sealed well.

As I stated before, ammonia triggers a reaction to avoid it. This fact makes it safe. You will never willingly get a hazardous dose when dealing with solutions. The fact that a sniff strongly repels the smeller does not predict that the sniffer had a near death experience, though it might seem like it.

Re: Anhydrous ammonia confusion

Don Stephan

Ammonia has quite an affinity for water molecules, forming ammonium hydroxide. Thus what many people refer to as "ammonia" is actually an ammonium hydroxide solution. When transported as a compressed gas, the product is likely pure ammonia.

Certainly "ammonia" causes a strong reaction when inhaled, but that does not necessarily mean it is completely safe in 30% and higher concentrations. When inhaled, "ammonia" burns lung tissue, which in turn causes swelling. People with compromised lung function may be less able to withstand inhalation, and children are more at risk because of their relative proportion of lung surface to body size.

And certainly when one inhales even a low concentration of "ammonia" he or she will want to avoid further inhalation. But there are many realistic situations where serious inhalation could occur around 30" ammonium hydroxide. One could trip in the tent when walking away from the just filled dish, if not wearing eye protection and a drop splashes into one's eye while pouring into the dish one could even fall over the dish and not see well enough to exit the tent rapidly. Before use, and if not all is used in the tent, the bottle could suffer accidental damage and leakage, a child's curiosity could lead to opening the bottle, and so on. Are any of these scenarios likely - probably not. Neither is being struck by lightning or an oncoming driver suffering a heart attack.

30% anhydrous ammonia can be handled safely but it can cause significant injury and I would want everyone to realize that there are risks not only from improper handling but also from accident.

Beware the vinegar and steel wool

Tim Greif - West of Chicago

I've done a fair amount of fussing with the vinegar and steel wool formulas at different mixes of vinegar/water dilutions with steel wool, and various controlled "steep" times for the solution and 0000 steel wool. Most of this has been to achieve the desired weathered grey hue on cedar stuff. Out of curiosity, I decided to try it on some oak pieces to see how it affected it. WOW. If you want to turn oak black, this is your solution. Even at relatively dilute strengths, the oak looked like I sprayed it with a rattle can of flat black.

Kevin's response about turning it lighter with sanding may be correct, but I'd recommend against using vinegar/wool solution on oak, unless you really want black.

Yup

John in NM

Ferric acetate turns high tannin woods black. I use it mostly on maple (turns that grey/green) followed by lye (goes to brown) and hydrogen peroxide (makes the brown more appealing). Ferric nitrate you can skip the peroxide, the color is nice with just the first two steps.

Any of these old school methods are extremely variable, even just between different pieces of wood of the same species but different trees. The difference in reaction between sugar maple, red maple, & silver maple is also pronounced.

I use these methods for fun mostly, and because I tend to be making single piece items, but I would never try it on furniture (unless it was oak and I wanted black) because it will look like a patchwork quilt!

But Oak is so pretty/dramatic

Kneale Brownson

Why make it dark?

Speaking of walnut stain

DizD

Do you remember years ago (maybe decades?) there were articles about a "secret" walnut stain? Take a dollop of roofing tar, mix in mineral spirits to make a walnut wiping stain. I had a refinisher friend who used this for repairs. I still have a little can from his "lifetime supply" gallon. Don't know if roofing tar is still available or if it has MSDS sheet.

Thanks all....

Barry Irby

The reason to make it dark is that the "customer" my DIL wants it darker. Unfortunately, she is in South Carolina and I am in Virginia.

I guess it's time for me to get busy experimenting and see what works best for me.

Re: Speaking of walnut stain

William Duffield

Yup. Roofing tar is also called asphaltum. It is the colorant in Watco Dark Walnut, and probably also in smaller amounts in their other walnut Danish oil varieties.

Re: Darkening oak Questions

HC Sakman

Hi Barry,

If you have so many different pieces (chairs, table, sideboard etc...) I'd go for a method that makes your life less complicated. Mohawk's "medium dark walnut" stain works well, has a reddish hue as the predominant color, though it is definitely brown. Also, Bona (for hardwood floors) makes very good oil based stains. Again dark walnut color is good but there are other shades to choose for the one's taste. Both brands dry fairly fast and both are oil based. I am just going for the easiest and most consistent method. Just my opinion.

Chico

Re: Darkening oak Questions

Jim in Burlington Ont.

Hey Chico,

Are you spraying your finishes now?

Take care, Jim

Re: Darkening oak Questions

TomD

I have used the steel wool in vinegar, and water. Both work, but the water solution seems easier to get a grey with. Either will go jet black with sufficient exposure. I rather like the result, it oddly goes like an ebony, almost, even though the grain of red oak is very crude. It has history. Dyeing oak, etc... just looks like a cheap wood with a bad finish to me. Never seen anything that looked serious.

However, one has to get what the job requires, and if one wants to get as close as possible to walnut, that is what one has to do, and I would not try it with the natural finishes. It's too bad how horrible all those cheap restaurants and kitchens were in the 80s and so forth, when one sees something like a green wood project in red oak, it can be beautiful.

Of course the British oak is a very different wood, it has tight grain, and an interesting dark colour. I haven't seen anything to match it.