Replies

1. 
   woodshaves | Nov 19, 2007 08:59pm | #1

   If your experiment fails, try iron acetate. It turns black walnut ebony black, and since it stains the tannins in the wood, keeping the wood long enough in the solution, penetrates into the wood. This experiment works for walnut inlays and the cost is only a quart of vinegar (less than $2). I do not know if you prepared iron acetate before, but all what is required is all the rusty nails, bolts, nuts, steel wires, and any other rusted iron you can find (do not use steel wool unless you remove the oil on it), placed into the vinegar for 2 weeks and a brown solution develops (iron acetate). Filter it and you are ready to stain. Do not tighten the lid on the vinegar while forming the acetate, generates heat and expands. After it is filtered, it may be closed tight. I keep small samples of avery wood available to me, stain with this solution, this way I know what color thay turn if I need.

1. 
   Buster2000 | Nov 20, 2007 01:56am | #3

   Very cool.  I just read about this recently and have been meaning to try it.  Is the effect on the walnut immediate?

1. 
   woodshaves | Nov 20, 2007 08:15am | #5

   As you apply it, the color change is immediate on any tannin containing wood, the longer it's in contact with the solution, the darker it turns (but black walnut turns black immediately). To stain a large surface (not required for small parts) it is advisable to add a few drops of liquid dish soap to break the surface tension (a surfactant) of the vinegar so the staining is faster and more uniform

   To clean the oil from steel wool, rinse it in paint thinner, but with so much rust around the house (old nails, screws, etc., what I do is to drop into a container rusty nails nuts and screws so when there is time to prepare more I have the iron available), there is no need to use steel wool.

1. 
   saschafer | Nov 20, 2007 08:24am | #6

   I don't think the iron has to be rusty, actually. It just dissolves faster if it is. If you're willing to wait a few days, "fresh" steel wool will dissolve just fine, too.

   -Steve

    

1. 
   woodshaves | Nov 20, 2007 08:16pm | #7

   The only reason why I mentioned "rusted" is because that most likely assures that the metal going into the vinegar is iron. Iron may form a variety of compounds containing complex ions of iron that are highly colored with other minerals, and we do not want other color contaminants. By providing iron oxide, since acetic acid is a weak acid, your final acetate product is formed somewhat faster. This is easier than explaining:

   Ka (ionization constant)=         [H3O+][C2H3O2-]                                                  

                                          ---------------------------------------- =1.8x10-5

                                                   [HC2H3O2]

   I try to add enough iron to my jar to have 1/3 of the volume as iron and 2/3 as vinegar, assuring a large amount of formed acetate gives me a deeper, darker coloration of the tanic acid in the wood faster/better.

2. 
   RW | Nov 22, 2007 08:37am | #8

   Update

   While I wanted very much to be able to come in here and say "eureka" and explain the great successes and the details, how I built the tube, etc (because when we see success we want to emulate) . . .

   pppft. It was a dud. I left the stuff in for over 48 hrs at 40psi. Bupkis. Its black as sin, but you can remove it with a couple passes of a scraper. I tend to think the dude who hit on particle size probably has it figured. The wood was soaked with the alcohol from the solution. Still very cold to the touch 30 minutes after being removed. But no color. So something penetrated quite well, it just wasnt the ink or dye in the mix.

   On a more humorous note, to you anyway. I also learned what a grand mess can be made when you drop about 2 gallons of black inky stuff on the shop floor. I made good use of a lot of sawdust, and that right quick. Real trucks dont have sparkplugs

3. 
   Clausewtiz | Nov 22, 2007 03:29pm | #9

   Great to conduct these experiments. Thanks for trying it, I really like the iron acetate solution, I think I am going to try that.I've been looking for a black stain for a small part.

4. 
   HWG | Nov 23, 2007 03:41am | #10

   You might have better luck by pulling a vacuum on it, rather than applying pressure, assuming that it is covered by the liquid.  Leave the vacuum for a few hours to help remove all internal air (until the bubbles stop).  When the vacuum is removed, and the wood is totally submerged, the air pressure will then force the liquid deeper into the wood.  Just a thought...Woody

5. 
   woodshaves | Nov 23, 2007 10:05am | #11

   The idea of low pressure looks good on theory for this, but will not work on a rigid container as the inside pressure is removed. The outside pressure to the container walls pushes on the outside wall, not the inside content with the liquid and the wood. If it is a container with flexible walls (such as a plastic bag) then the atmospheric pressure is transmittable to the inside content, but in this case, when the air is removed, the liquid volume is not compressible to transmit the pressure to the wood inside, liquid and wood are at the same pressure, the wood is not at a lower pressure.

2. 
   paretsky | Nov 20, 2007 02:41am | #4

   So how do you remove the oil from the steel wool? Is it as simple as washing with soap and water before putting it into the vinegar?"Light the lamp, not the rat! Light the lamp, not the rat!!"
   Rizzo the Rat, A Muppet Christmas Carol

2. 
   saschafer | Nov 19, 2007 09:00pm | #2

   Pigments, such as those contained in India ink, are composed of relatively large particles (about 10 µm in the case of India ink). Dyes, on the other hand, are made up of individual molecules that absorb light; they are on the order of 10 nm in size, a thousand times smaller than pigment particles.

   So that's the first suggestion: Use a black dye (e.g., TransTint) instead of India ink, as the dye molecules are more able to negotiate smaller nooks and crannies in the wood.

   I don't think pressurizing the "dying chamber" is going to get you that much, because hydrostatic pressure is not what you're fighting here. I would first dry the wood thoroughly by baking it at 225-250°F in the oven, and I would add a surfactant, such as a few drops of dishwashing detergent, to the dye solution.

   Another possibility is fuming with ammonia. The wood won't get as black as it would with a dye, but the color will penetrate very deeply, probably all the way through a 3/8" piece.

   -Steve