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In this forum and others there seems to be a lot of questions asked about Cherry blotching. Having never experienced this phenomena in almost 40 years in working with wood, I thought I would share how I have avoided this problem because I really don’t think that I could be that lucky.
As with any wood, surface preparation, IMHO, is the most critical yet often over looked due to impatience in getting the project done, tediousness of the operation, or lack of knowledge. When ever possible I avoid abrading (sanding) and use hand planes and scrapers. The primary reason that I do this is that regardless of how fine the grit is you will still end up “roughing” the wood fibers as opposed to slicing them. By abrading the wood, I feel that one leaves them selves open to problems in the application of stain and/or finish. Only until all surfaces have a glass smooth appearance will I move on to the next operation.
Cherry is one of the few woods where sapwood and heartwood is not only acceptable but, desirable as well. Because of the scarcity of Black Cherry in my neck of the woods, I have incorporated the use of stain and “sun tanning.” Since I do live in an area where there is frequent sunshine I will darken the pieces by laying them out in the sun before after surface preparation for about 4 hours.
I use Minwax Cherry Stain (#235) which is an oil based stain that they claim is also a sealer. I brush the stain on with medium loading going with the grain. I work the stain in by going across the grain and then with the grain. I will let the stain stand for about 10-20 minutes depending on the wheather. The temperature determines length of time. After the stain has set, I use a clean 100% cotton “rag” (old T-shirt) and wipe off the excess stain. If you buy your rags make sure they are lint free. Some outlets sell packaged remnants of 100% cotton T-shirts and skivies, I have found that these are no good for applying finish since they still contain the sizing. A better term to use might be “rub out.” I will go with the grain first with moderate pressure, then use a circular motion with the same pressure, then will use a very light pressure, going with the grain, to “feather” or blend so the surface is “uniform” in shading or tone, if you will.
After letting the stained piece dry for 24 hours, I am now ready to apply the finish. On high end pieces I French polish but, typically I use Minwax Wipe On Poly in a satin or semigloss. When this product arrived here a couple of years back, I was skeptical. After some experimentation I was impressed enough to incorporate this product into my finish operations. Minwax advises against the use of tack clothes with this product and I am here to tell you that it is good advice. Tack clothes do leave a small amount of residue behind that will affect the final finish. I vacuum and use compressed air to clean the piece prior to finish and sanding between coats. I recommend against the use of #0000 steel wool because of the deposits left behind.
I apply the finish, again using a clean 100% cotton “rag”, wiping it on in a circular motion in sections about 2′ square and then go with the grain. It is important to work quickly, feathering each section into the last section. I use 220 or 320 grit aluminum oxide with a very light touch between coats. At 70*F drying time, sanding, is about 4-6 hours. Minwax recommends 3-4 coats, I usually go with 6. I sand the second to last coat with 600 grit silicon (dry) with a very light touch.
The first project that I did using Minwax Wipe On, was my on my kitchen cabinets almost three years ago. It has proven to be an extremely durable finish.
In conclusion, I would say that using the above techniques should eliminate any “blotching” as it is a technique that I have been using for over 25 years as a professional, with the exception of using Minwax Wipe On Poly. For those who have further questions, feel free to e-mail me at my personal e-mail address. For those who might be skeptical, find a piece of Cherry with both heartwood and sapwood and try it, you will be satisfied.
Dano
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Dano-
I am replying for two reasons:
1) I read something the other day that implied that kiln dried cherry blotches more than air dried. This was the first I had heard that (and I have read quite a bit about this lately). Have you found this to be true? Do you normally use kiln dried or air dried cherry?
2) I tought this post was excellent and I just wanted to see it get to the top again where people are more likely to read it.
Peace.
-Rob
*Rob,I've never heard of this either. My only thought would be that if the Cherry is kiln dried too quickly where case hardening, moisture in the center might cause problems with finishing.I use air dried whenever possible. Thank you for your kind words, I was surprised to see this here.DanoPS I do see a "typo"; I suntanb after surface preperation.
*Dano & RobA very nice piece, worthy of publication. I have used a similar process for over thirty years, using other brands of oil based products, topping it off with poly-varnish on hard use (horizontal)surfaces,& six...or more coats of hand rubbed lacquer everywhere else, with excellent results. The addition of a filler in the initial stage, adapts it to porous woods.I haven't experienced blotching of cherry since I quit using kiln-dried lumber ... the S4S stuff available today is usually case-hardened from rapid cycling times, or was planed with dull knives. Unless you remove this "case", which is often 0.010" to 0.030" deep, you are likely to experience the same result as when one takes short cuts with Dano's surface preparation recipe ... uneven absorption of stain materials.I have found that proper sanding technique on cherry, birch & maple can also be successful, providing you whisker & touch sand TWICE, following your last sanding with 240 or finer. It is vitally important that once the thoroughly dampened surface has dried, you use fresh, sharp 240 to 320 paper or 4/0 steel wool to "shine the surface" free of whiskers. If you remove visible material with this step, you're sanding too heavily Skip this last series of steps, and even air-dried material can be prone to blotching. Good Luck, JohnP.S. It'll break your heart to see all the curly & quilted cherry used for pallets and crating lumber, here in middle Tennessee. It's like curly maple further East .... the furniture companies hate it, so it goes into the junk wood pile at the mill, and there's too few of us making the circuit to haul it home to sticker & stack before it checks badly. I walked past, perhaps 18) 3 x 4 cherry skid runners - 9' long, just today, .... oops! there went a tear!
*John,What can I say? Have half a mind to head east with a flat bed and load 'er up with some Tennessee pallet wood.....what a waste.Your comments are interesting in that so few people really even know how toi sand properly. That was the very first thing I learned back when I was an ankle biter. Any who, I figured that this would have been in the archives by now since it is almost a year old and Rob was the first to post a response, that's why it surprised my when I saw it.Dano
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