I am working on a bookmatched taple top of curly cherry. I want to pop the curl and darken the cherry, but avoid blotches. I’ve done that in the past by mixing dye with lacquer thinner so that the dye solution evaperates when the spray hits the wood, but I don’t like the effect – it’s too uniform – too much like a factory solution. I’d like a more medium look somewhere between factory and sloppy. Most of the other solutions I’ve studied involve thinned linseed oil at some stage or another and in my experience there is no more sure way to create blotch than linseed oil ( but maybe I haven’t thinned it enough). This time I’m thinking about applying potassium dichromate (FW #140, p. 130) to darken, then dewaxed shellac, and then spray on satin lacquer, and hope the curl pops through. Has anybody tried this? An other ideas?
p.s. I love working cherry, but finishing it makes my brain hurt. Help!
Replies
Chairwright
If you want it to darken, why not just use multiple coats of garnet shellac?
Dichromate is some nasty stuff. Have you tried using lye (drano)? Easier to get, and nasty too, but easier to manage. You do have to be careful to apply it evenly or it will streak.
PS. I was on a new homes tour recently, and saw a new kitchen cabinet finish. I don't know what it's called, but to me it looked like intentionally blotchy cherry veneer. It was like they sprayed random blotches onto the wood. Go figure.
Stantheman: You bring up an interesting point. I noted that the FW article advised to use a good respirator. I figured I'd use the respirator I normally use when I spray lacquer. The cartridge filter type. I now wonder if the lacquer cartridges are adequate.
Oddly enough, personally, I am not bothered by the blotchiness of cherry, but I figure customers would be, especially if they're shelling out good money for the product. Hey, if blotchy cherry becomes popular, I sure know how to do that! Chairwright
Here is the way I do it. I would try it on the backside of a piece that has some figure to see if it's what you are after. Click on the "staining" link when it shows up.
http://www.miterclamp.com/radius/pages/Installationsection.htm#stainingtop
Clampman
Jim: Thanks, that's neat solution, and nice pics. I've got to try it. As a quicker alternative to mineral spirits, do you think that thinned water base pore filler might work? Flood it on, work it in, and sand it? Chairwright
I suspect that pore filler would dull the chatoyance of figured woods, but I have never tried it. You might want to post a message on Wood Central addressed to Michael Dresdner. He usually hangs out there quite a bit.
Clampman
There are a number of finishes that look good on cherry, including curly cherry. Mostly it's a matter of what you like and what steps you're comfortable with. Here's a few options;
1) "Suntanned" Cherry
2) Aged a Little
1) - A week next to a window will darken cherry a little. The top of the sample was covered and the bottom exposed to sunlight. More than a week has a lot less effect and eventually (it takes several months) the sun will start to bleach color from the wood.
2) - Here's the same sample a couple months later. The coloring has evened out pretty well and the wood is a little darker. I took the picture in sunlight to show the directionality (aka - chatoyance, shimmer) in the wood. The finish is lacquer though one of the blonde shellacs will look very similar.
This cherry sample has a lacquer only finish but looks a little "blotchy" from some angles. Using an oil or an oil finish would increase the blotchy look but even a non-penetrating film forming finish like lacquer (or shellac) has the look sometimes, depending on the board.
After planing cherry, you can see the areas of the wood that look darker than the surrounding wood. These are the areas that look blotchy once the finish is applied. Wetting the wood with a solvent like mineral spirits or naphtha will give you a good idea of how the wood will look once it's clear coated.
Lacquer Finish
While lacquer and shellac keep blotching to a minumum, the resulting look on curly cherry is not very "lively." Rather, it's more a muted look than some of the alternatives; not quite the striking impact the wood is capable of producing.
The large improvement that oils and oil-base finishes have on the directionality of cherry can be used to your advantage on curly cherry. Since the wood appears "blotchy" no matter what finish you use, why not go with it and get the most effect from the figure and depth? In the sample below, I used danish oil on the left side and boiled linseed oil (BLO) on the right side. Both oils have nearly identical effect on the wood; the look of depth in the wood is enhanced quite a bit as well as darkening it a few shades. The effect is definately more dramatic than the lacquer or shellac alone.
Danish Oil & Linseed Oil
Following advice from Jeff Jewitt, I've experimented with using a very light coat of oil instead of flooding the wood. Basically, you spread the oil as far as possible, wetting the surface of the wood just enough for the oil to take effect. This technique reduces the blotching while improving the directionality. It also dries much faster than soaking the wood with the oil/oil-base finish.
The light oil treatment works on curly cherry as well as cherry with clear, straight graining (little or no "dark" areas).
Light Coat of Oil
Taking the finish process one step further, here's a technique that adds some color and grain definition without adversely affecting the depth and directionality in the wood.
1) Glazed Finish
2) Angled Lighting
1) - In this sample, the wood was sealed with a thin coat of finish. I used a 1 pound cut of blonde shellac, though you can use other finishes if you thin them to around 5% solids content. Once the shellac dried, I sanded it smooth with very fine paper and then wiped a glazing stain over the shellac on the bottom section of the board. The glaze added a little color and really accentuated the grain in the wood.
2) - Here's the same sample after it had aged a while and got darker. I took the picture in bright light so that the angle of the light showed the depth in the wood.
For a little added directionality, you can apply a light coat of oil or oil-base finish to the wood before the shellac. Just make sure to keep it very thin and spread it as far as you can. You can use BLO, tung oil, danish oil, thinned oil-based varnish/poly, or Minwax "Natural" stain in the "oiling" step.
Another alternative is to first dye the wood a very light amber or orangish/brown and then glaze. These colors work well with the natural coloring in aged cherry. The dye will add some color and "pop" the figure improving the directionality much like the oil. If you apply the dye by spraying a light wet coat and don't wipe, it will keep blotching to a very minimum.
3) Dyed and Glazed Finish
4) Angled Lighting
To get an instant aged color from cherry, use lye. 2-3 tablespoons of lye mixed into a quart of water will darken cherry a lot. At first, the color is too red, but in a matter of weeks the intensity of the red fades and the wood has a natural aged look to it. If you use lye, make sure it's just lye. You can get straight lye from the grocery store in the drain cleaner aisle; it's made by Red Devil. Don't use one of the brands, like Drano, that contains other chemicals in addition to the lye. There's an article on the use of chemical stains like lye at this link - Chemical Dying Techniques - including the safety precautions. In the sample below, I used 3 tablespoons of lye per quart of water.
Cherry "Dyed" with Lye
4) Angled Lighting
If you're familiar with spraying a colored finish over a sealed surface (called a toner), you can add that step to any of these finishes for added color and depth. One of my favorite finishes on cherry is the dye and glaze finish above followed by a toner. In the pictures below, the door on the far left is dye only; the one next to it has been sealed and glazed. In the picture on the right, the door on the left has been dyed, glazed, and sprayed with a toner; the one next to it is dye & glaze.
Dye on Left & Glaze Added Right
Toner Added
Paul
Paul S: Wow! I never expected to receive such an expose as you posted, complete with excellent photos. If your work on this subject hasn't been published it should be. The link to chemical dyes was also greatly appreciated. There is great merit in all the ideas I have received to my issue. I think I'm going to try a 1% mordant potassium dichromate more or less to darken and even out the color like the dye spray would, and then thinned BLO to accentuate the curl withing the "homogenized" color, so to speak. Then superblond and then lacquer. We'll see what happens. Chairwright
Before you try dichromate, look up the materials safety data sheet. Carcinogenic and toxic at 0.1 ppm concentrations. Has cumulative effects. A hundred years ago, before dyes were available and people knew any better, maybe there was some excuse for using it. Not today. Don't know why people keep suggesting it. Exceptionally nasty stuff. You'd have a hard time finding anything more toxic.
Bob: I'm sure you are correct about the dangers of potassium dichromate. I'll read the safety sheet which comes with that which I have ordered (I presume). I've already read about the dangers of it, but there seems to be scant information on the nitty gritty about how to use it safely. Here in the Midwest we grow the world's food supply and we do it by the safe use of extremely dangerous chemicals, applied in concentrations which are also safe for the food supply. It takes know how and constant training and education. So my focus is not on the danger itself, but how to use dangerous stuff in a safe way for me, others, and the environment. I'm going to start another post just on this stuff and continue research to find out, for example - exactly what type of respirator is necessary, do you have to neutralize the acid after use, does it retain its toxicity after it dries on the wood - i.e. is it safe to sand the wood, etc. Chairwright
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