Lime technique (Neanderthal Finishing?)

[Ron Brese]

I have an extensive finishing background, however most of my past work has always included many different versions of blockers, dyes, stains, and a different array of top coats. I have lately begun getting so enamored with shellac and french polishing that it occurred to me that maybe this would be considered more of a Neanderthal version of finishing. So this set me thinking about methods of coloring that would not include pigments and dyes and would rather induce coloring thru chemical reactions. I want to try and stay away from things that are potentially hazardous, so I have been doing some experiments with hydrated lime dissolved as best as possible in water. So far my initial experiments have yielded very good results in mahogany & cherry, and virtually no color change on pine, and minimal color change on maple and curly maple.

I stil have to fine tune the exact measurements of lime to water and duration of application, however the intial experiments are quite encouraging, expecially in regards to aging cherry quite rapidly.

So my question is this, are there others that have pursued my Neanderthal finishing methods and are you willing to responds with your on findings? I'm sure I'm not the only person that ever decided to color wood by obtaining a reaction to lime so I would be interested in hearing from others about this subject.

Thanks,

Ron

[Dave Anderson NH]

Hi Ron, I've came to the point about 4-5 years ago that the only coloring method I use on mahogany is lye. It's something with a potential to be dangerous if handled carelessly , but with a few precautions is fairly safe. With gloves, apron, a face shield or safety glasses you are pretty much protected. The mixing is done with 1-2 tablespoons of lye to 1 quart of water. Note that the lye is added to the water and not the other way around or sputtering and splashing will occur. No metal containers can be used or they will corrode and cause potential problems.

I flood the lye solution on heavily with a sponge or a rag and then give it 24 hours to dry. While some folks don't use the second step of neutralizing claiming that it is unnecessary, I feel safer doing it. I take a pint of water and add 2 tablespoons of white vinegar. I carefully wet a sponge and wring it out until it can't drip on the workpiece. I wipe all the areas I applied the lye to being careful not to allow any drips off the sponge. Any dripping off the sponge will result in discolorations and having to start the whole proceedure from square one. DAMHIKT Finally let everything dry for 24 hours and apply a sealer coat of shellac. From there it's the topcoat of your choice.

[Kim Spence]

There is an article in a Taunton press book I own, can't remember if its "Finishes and Finishing Techniques" or "More Finishes and Finishing Techniques" that lists several chemicals that can be used to change the color of wood.

A few I remember without pulling out the book (its at home and I'm at work) - ammonia fuming, potassium dichromate, sodium hydroxide (lye), iron oxide (rust) mixed with vinegar.

I think most of these react with tannins in the wood, so makes sense that you won't see much reaction with low tannin woods such as pine/maple. To get a color change in these woods you must first add tannins, then add the appropriate chemical.

I'll take a look at the book later and reply if there's more.

[Kim Spence]

Here are the details on the article I mentioned in my previous post on this thread:

Book "Finishes And Finishing Techniques" by Taunton Press, 1991

Article in the book is "Old-Fashioned Wood-Coloring" by George Frank, reprinted from Fine Woodworking Sept 1987.

Excellent short article on some the various ways to naturally dye or chemically change the color of wood.

The chemicals discussed include
Alum
Potassium Dichromate - very poisonous, be careful
Copper Sulfate - used by plumbers to kill tree roots that clog sewer lines
Ferrous Sulfate
Stannous Chloride
Potassium Bitartrate - cream of tarter from the grocery store
Sodium sulfate
Ammonia
Tannic Acid
Calcium Oxide (quicklime)

The same book contains two other articles that fit this subject:

One by Tom Dewey called "Unlocking Cherry's Color" that discusses using Lye to color wood, and one by John McAlevey called "Ebonizing Wood" that discusses using a brew of vinegar and iron to blacken wood.

Hope this helps.

Kim

[Ron Brese]

I want to thank everyone one for their replies. I think before I go to the more caustic chemicals, I'm going to do more experimenting with the lime.

I got started down this road because of something I happen to notice while building my house. I was stirring a mixture of mortar mix and water with a scrap of cherry wood when I was applying a scratch coat of mortar on the foundation of the house. I used this stick everyday for a couple of days and noticed that everday after I used it and cleaned it with water it was darker. I attributed this to the lime content in the mortar mix, and I am getting similiar results with the hydrated lime.

Thanks, I'll keep you posted on the results,

Ron

[Stephen Gist]

I am mahogany panelling in sapele and making a cabinet in my bathroom in sapele and am interested in the lye finish. does anyone have any pictures that they could share of the finish?

[Ron Brese]

In the process with the lime I am looking for something that has the appearance of very old aged cherry which just can't be accomplished with dyes and stains. I am getting some good results, but I am finding out that you do indeed get blotching if you don't use a blocker as with prior methods that I have used for coloring cherry. A sample done yesterday using a blocker and the lime yielded a very nice consistent yet aged look.

Using the prior methods of dyes and stains I could get boards of wide ranging color to appear very consistent, it remains to be seen if I can do that with the lime technique, however the coloration with the chemical reaction of the cherry is so unique that I really think that it is worth pursuing. The worst case would be that to use this technique one would have to been very careful in selecting boards for a project and it may lend it self to smaller projects for that reason.

My next experiment will be to try this method on two boards that are heart wood but different in natural coloration and see if more or less exposure time to the lime can be used to bring them to the same color.

I have developed a lot of my finishing processes by doing just what I am doing at this point, ......lots of experimenting.

I'll keep you guys posted on my progress and will try to post some pics soon.

Ron

[Ed Falis]

Pics would be great, Ron (you too, Dave, if you have any).

- Ed

[Dave Anderson NH]

I think there are some pix from back about 3 years ago when I did a Mahogany breakfast table using lye for the coloring and then garnet shellac. It's amazing how red-purple the mahogany is before the shellac is applied.

[Jim Becker]

I believe that Alan Turner used liming for that wonderful Newport style piece he did awhile back that was also featured in the FWW gallery. I've seen that piece in person and it's outstanding in color.

[Ron Petley]

Steel wool soaked in vinigar for a few days or more works on some woods, it will turm oak black. I used some on box elder burl and ot worked very well, brought out the grain to a nice "brown" color.
Cheers Ron.