Replies

1. 
   RMillard | Jan 17, 2005 02:46pm | #1

   From the description, it sounds like more time should be spent on surface perperation. I make period reproductions, where the occasional spot of tearout is acceptable, but I do everything in my power to elmintate it, either by carefull planing or scraping, and as a last resort sanding ( although my opinion is that sanding should never be From the description, it sounds like more time should be spent on surface preparation. I make period reproductions, where the occasional spot of tear out is acceptable, but I do everything in my power to eliminate it, either by careful planing or scraping, and as a last resort sanding ( although my opinion is that sanding should never be looked at as a way to remove stock, but only to refine a surface) . Also, I sand raw wood to 320 grit before finishing. I never apply filler to raw wood. It will muddy the grain, leaving less clarity than is optimal. I've never used PD, but instead lime, but the effect they have are similar. My finishing schedule, is careful surface preparation, i.e. hand planing, thoughtful scarping, light but thorough sanding with 220 and 320 paper ( never anything more coarse than 180 in a power sander). Raise the grain, resand lightly with 320 paper. Apply coloring chemical. Apply oil or dye tinted oil if you want to alter the color. After the oil has cured a day or so, I apply a thinned down coat of Constantine's oil based filler, then follow with whatever topcoat you want, when the filler has dried several days. Crotch veneer is difficult to work with as far as finishing goes. I reject any veneer that has what I call loose spots or uneven thickness, as it only adds to the difficulty. The difficulty in finishing crotch as you noted is the center will turn very dark. The best approach is to select crotches that are light in color. Also, if you don't have to book match, look at the veneer for the lightest side and put this out. I've tried several ways to finish crotch veneer, one is to dye it to match the solid wood, and coat with varnish. The dye will color evenly and the varnish will pop the grain without darkening the center too much. The other is to just clear coat the crotch and let it dictate the color of the rest of the piece ( this is my least favorite approach). Finally and best, with careful selection of the veneer is to apply a dye tinted oil to the veneer. This will color the veneer with great color and depth, and the rest of the piece can be finished to match. I use the varnish oil or Danish oil sold by Tried and True, they will not darken the center as much as standard linseed oil will. Occasionally I can spray the lime on the veneer, but this can only be done after a test sample, as it can lead to disaster ( don't ask how I know that). I have attached a photo of a pair of light house clock cases finsihed with the last method, along with the veneer used for the column. If you look carefully, you'll see that I did not follow my own advise, with the case on the left. The veneer was glued on with the dark side out. The other case displays a far better grain pattern.
   Rob Millard

   
   

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   Edited 1/17/2005 6:47 am ET by RMillard

   
1. 
   JHarveyB | Jan 17, 2005 06:32pm | #3

   Thanks for the info, Rob. I am somewhat constrained in the finishing routine by the fact that I've got the insides and fixed panels finished before I glued up the main carcases. And it took me 5 months of tedious piddling around with various materials and routines to get a finish that was both acceptable to my nephew (a lover of all things antique, including finishing materials) that my partner and I could actually imagine doing. I agree with you on surface preparation, tho I learned from a church furniture company that when using very dark stains (and I'm essentially in that situation here with the tinted paste wood filler), sanding past 180 makes the stain bounce off the harder areas, leaving too much contrast. For our normal finishing (Waterlox transparent over local hardwoods like cherry & walnut) we start with 180 or 220, and finish with 400. Much of the wood for this project was furnished by my nephew, and some of it has serious soft spots in the rowed areas where the fibers just bend over, no matter what tool or degree of sharpness one applies. Even hand sanding doesn't deal with it; we use an old vibrating sander on it. I guess I didn't mention that the crotch pieces (furnished by nephew) are actually solid wood (where the word "solid" is somewhat of an overstatement.) The tear-out can be more like small, deep holes in the wood; I am reluctant to seriously diminish the thickness of the panels as the doors are already made, including the rebates for the panels. There are also numerous small checks (that go all the way thru the panels) that I'd rather fill with something. I'm doing a lot more sanding on this soft rowed stuff than I've done on any other project. We don't even bother owning a belt sander (except for a 1"x42" one we use for sharpening lathe tools.) Anyway, thanks for your tips.
   Harvey

2. 
   OneofmanyBobs | Jan 17, 2005 05:44pm | #2

   You do know that dichromate is highly toxic and carcinogenic?  The word HIGHLY is stressed.  I won't have it in my shop and certainly would never allow it in the house.  Look up the materials safety data sheet.  Toxic threshold level: 0,05 milligrams/cubic meter.  One ounce will contaminate 56,000 cubic meters.  Cyanide is candy in comparison.  Potassium cyanide toxicity threshold is only 5 milligrams per cubic meter.  100 times less toxic than dichromate.  Cyanide is only rated as a class 3 hazard.  Dichromate is class 4. Both are absorbed directly through the skin.  http://www.jtbaker.com/msds/englishhtml/p5719.htm  Anybody who sells this for woodworking purposes is highly misinformed.  100 years ago, they didn't know any better.  Now they do.