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Eliminating gray stains in green wood

Matt Meadows

Matt Meadows

Joined
May 13, 2005
Messages
171
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Location
Charleston SC
Got a problem with some Magnolia I got a while back. Now that I actually know how to turn bowls, and have the tools to do it, I can't use my magnolia b/c it's all gray stained, not unlike how holly does.

Any way to get rid of the stain? Or am I cursed to toss out this magnificent wood? It's not everyday you get free magnolia, I love the stuff. The bark smells like eucalyptus.
 
There is really no way that I know of that will remove the gray stains - I wish there was.

OTOH - I have some maple that has a beautiful grain and ugly gray stains. I was practicing a new (for me) shape. I liked the final results. I had some Miniwax Wipe on Poly (Clear Satin) left over from a flat project and decided to give it a try on the bowl. The ugly gray stains turned into a rustic brown color😱, which happened to fit the piece nicely because it has a natural edge. 😀

Sometimes you win a little...
 
a couple of thoughts on mold/fungi stains:

fungi or molds need moisture to grow and discolor the wood. so if you remove the moisture, there is less fungi growth, and therefore, less staining. so how to remove the moisture??

while at a john jordan demo, he showed how he reduces staining. after turning, he uses air to blow out the moisture. i've successfully used this technique as long as i worked the wood long enough to blow the moisture out.

also, i would imagine that soaking in some oxygen-reducing liquid would also reduced fungi growth -- alcohol or a watco oil type might work, however would probably darken or yellow the wood.

the flower-drying folks use silica to eliminate moisture before mold and fungi can get started. there's a brand of kitty-litter, pearls, that is pure silica that is easily found and can be reused (as long as the cats don't get to it first).

after the wood has been stained, try using the 2-part bleaching product. i've found that after repeated application the stains will not be totally removed, however they'll be signicantly reduced.

and finally, don't use deft as a finish... it significantly yellows over time. i've been very happy with water-white lacquers.
 
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I have had the same black staining show up on sycamore. Doesn't show up much until a finish coat is applied. I tried clorox bleach, but not much imporvement. Next went to the hardware store and got a stronger dry chemical that is carefully mixed with water. - I forget the exact name. But still not much improvement.

Final attempt was to go to a OLD TIME paint store (where they have experienced sales people) and was directed to two part bleach. It comes in two bottles that one mixes in small quantities. This worked!
Be careful though, it will still tingle your skin after the bleach is fully dry. I found that I need to neutralize with vinegar before I could safetly handle the bowels.

Key point is that the two Part Bleach, also referred to as A, B bleach, removed the black spots from the sycamore. Had much the same problem on a maple piece and the two part bleach again cured the problem.

Hope this helps.
 
The other option is to see the stains as a feature, not a problem. Grey and black stains can add alot of character to a bowl or vase.

Dietrich
 
GREAT! Thanks for the help!!!!

Lol, I got to hit the road. The news just had a story about a microburst (a very forceful wind, like a laminar-flow "tornado") that hit a local community and downed several trees, and they showed several medium maples and sycamores that fell over. Gas up the chainsaw and make some dust...

CHA CHING.
 
The stains, though different colors, are generally referred to as "blue stain" in the lumber industry, and they spend big bucks to keep it from occuring on their poplar and other lumbers. The stains are caused by both mold and fungi and if you do a google search on "blue stain" or "poplar blue stain" you will be returned oodles of information on the subject. Most of it will tell you what others here already have - you can't really stop it, and there are (very) few things that will minimize it.
 
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