Hello All,
I am new to wood working and am going to veneer a blanket chest for my wife. The field will be cherry with american walnut for borders. I have been reading all I can about finishing and have come up with something I would like to try. I have been recommended to try the following procedure for the cherry due to the blotching nature of the wood. 1)coat the entire surface with boild linseed oil and wait 20-30 min then wipe off the excess. 2)wait a week for the oil to “cure” then apply 1 to 2 coats of dewaxed shellac…….may be blond to garnet to blone with dyes in it depending on the color I want. 3)go over the shellac with 0000 steel wool and give 2-4 coats of minwax satin polyurthane. My questions are these:
1)does anybody have any experience with method?
2)is the oil used to “pop” the grain or is it used as a sealer coat to ensure the blotching doesn’t occur. I know the difference between blotching and the normal color variations of stain or coloring coats not soaking into high density or closed grain. I want an even color through out the wood. I do not want to ruin the entire piece due to my messing it up with the finish.
3)can this method be used to control blotching on other woods like quilted maple, or adler, etc.?
Thank you for any help
Replies
I just bought a new finishing book, partly to help with anticipated blotching problems I expect to see when I work with Alder. The book is "Great Wood Finishes" by Jeff Jewitt. He provides 4 general approaches to solve this problem:
Specifically with regard to using a Linseed Oil washcoat, he recommends mixing 1 part boiled linseed oil with 6 parts mineral spirits. Flood surface. Apply stain while surface is wet or after it has dried for a day. Recommended for an oil-based stain.
Other washcoats involve shellac (my preference) which is compatible with various types of stain, or thinned lacquer.
Based on responses I've gotten to my questions about blotching, I don't think there's anything that ensures the blotching doesn't occur! You can test the wood prior to finishing by flooding it with naptha or mineral spirits. It's best, especially if this is your first cherry-finishing expedition, to test a separate piece before going to the finished product.
I've only limited experience with finishing, but there's something about using straight, undiluted linseed oil and waiting for it to 'cure' that doesn't feel right to me. Maybe someone out there (Sgian???) can make some recommendations.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Your finishing schedule is fine. If you dissect the steps, here's what you get.
1. Apply linseed oil to highlight the natural grain of the wood. Boiled linseed oil cures slowly to form a thin, non-protective film. The oil will enhance the wood's grain and figure - "popping the grain". If you are going to add color after the oil, it will serve as a base coat to prevent penetration and blotching.
2. Apply shellac to seal the oil and provide a base coat that poly will adhere to. The shellac should be dewaxed so the poly will stick to it. Some brands of poly are not recommended for application directly over oil-based products. You can add dyes or pigments to the shellac to add color to the wood - this is called a "toner." Dyes are transparent and will add color without obscuring the wood grain at all. Toning is a process of coloring wood that results in very even coloring - nothing penetrates the wood, so blotching cannot occur. A glazing stain can be used with, or in place of, the toner at this point to intensify/deepen the color. A glazing stain is not the same as a typical wood stain - it's made specifically to work between clear coats and it's important to avoid incompatibilities between the glaze and the clear coats.
3. Poly is used to add durability to the finish. Polyurethane is a type of varnish that is formulated for increased resistance to scratching, wear, heat, and household chemicals. These coats provide the desired sheen (flat, matte, satin, semi-gloss, gloss) and protect the wood. Pick a sheen that fits your taste and the piece of furniture.
As Forrest Girl replied, there are a number of ways to avoid blotching. The book she recommended by Jeff Jewitt is often cited along with Bob Flexner's "Understanding Wood Finishing."
If you thin the boiled linseed oil before applying it won't have any negative affect - it will be thinner and dry a little faster. A 50/50 mix is very common for the application you are describing. I add "japan drier" to oil based products to make them dry overnight - I can't wait a week. For your first piece, I'd say avoid trying toners - stick with a natural look and practice toning and other techniques on scraps before finishing a "keeper."
To Forrest Girl;
Try a good quality gel stain, like Wood Kote or Bartleys (not Minwax), on some scraps of alder. I think you'll be pleased with the even coloring. If you want even more control, use a 1 lb. cut of shellac as a washcoat, sand lightly with scotchbrite/steel wool, then apply the gel stain. I don't think you'll see a need for the washcoat, but it is an option. Blotching IS completely avoidable - if you're not getting the results you want, repost with a description of the color you're aiming for and I'll see if it's something I have in my tool kit.
Paul
F'burg, VA
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