cherry problems

[paul coyne]

Hey all, i recently recived a large amount of cherry which blew down and have been trying some thin walled green bowls they are all end grain as the diameter is about six inches at most i have been allowing these to dry naturaly but i notice they are geting a dark patchy stain not long after i have finshed turning, any ideas on what this is ? and how to posably stop it from hapening ?

regards Paul.

[Steve Schlumpf]

Paul - Welcome to the Creek! I love turning cherry - so congrats on your score! Not sure what would be causing a stain in the cherry. Any chance you can post a photo or two of the problem bowls?

[Julian Nicks]

I know that cherry will darken when exposed to light. My only suggestion to you would be to make sure the blanks aren't in any direct sunlight.

[Jeff Nicol]

Paul, Cherry is one of those woods that is affected by many things, the sun darkens it, if you have sweatty hands it will cause dark stains. Also I notice that it will get dark from contact with steel when it is wet. So don't put any steel wool on it when wet. The sap in the wood will darken just by being getting air to the wood. So when you are turning the sap and water stays in the flat grain and leaves the end grain causing the end grain to dry very fast and the flat grain not so fast, this could be the culprit. I think you could take some water to do your wet finish sanding to even out the moisture or use naptha and let it soak in and replace the water when you finish it. I am just trying to think of everything that may effect the cherry wood so give some things a try on some random scraps and see what happens.

Good Luck,

Jeff

[Steve Frederick]

Iron? I've seen this on Oak and Apple. It could be from a freshly ground tool...

[Leo Van Der Loo]

Yes Iron stain was my thought also, with wet wood like Cherry and Oak, Walnut and others, all you have to do is wipe the sap from the lathe bed and then grab onto the wood and you will have staining, also if you would lay it on a steel plate or on your lathe, any iron that gets in contact with the wet wood will do this, DAMHIKT :-((

[Nathan Hawkes]

Another vote for iron/steel staining on the cherry. One other possibility is mold, as I'm not exactly sure what you're describing is iron stain. I've been working with a lot of beautifully burled/ambrosia/spalted red maple--yep it has all three!, and it also mildews terribly if I brown bag it while it dries. I was DNA soaking all the pieces and bagging them to dry, but I've given up for this particular sourced wood. It always gets very pronounced black spots all over it when I remove it from the paper bag. It isn't actually that bad if I let it dry naturally(counter intuitive I know, due to that the alcohol one would think would kill a lot of mold spores), it does warp & crack a bit more, but as much as I got from the arborists, it doesn't really matter. Are you bagging the cherry as it dries?

One bright side to the mildew/mold stain is that it sands off, however does require 80 grit paper to sand out, which makes for a lot more work. Iron staining in cherry seems to go pretty deep, IME.

One thing I might try on some wood you don't care about, as a test, is to use a very weak--maybe 3-5% bleach solution. I personally haven't tried it, but keep meaning to. It shouldn't go too deep, especially in wet wood, and any mild bleaching should sand off. However, as a caveat, I have NOT tried this. Maybe tomorrow...

[Leo Van Der Loo]

Nathan I have used Oxalic acid to take out iron stain, works well unless you have an open grained wood like Red Oak, as the staining can go in very deep, I never had a good success taking it out of Red Oak, so I try to prevent it, and staining the whole piece if I didn't keep it off.

[Nathan Hawkes]

Nathan I have used Oxalic acid to take out iron stain, works well unless you have an open grained wood like Red Oak, as the staining can go in very deep, I never had a good success taking it out of Red Oak, so I try to prevent it, and staining the whole piece if I didn't keep it off.


Sorry to thread hijack, but Leo, where do you get Oxalic acid?? I've heard of it many times, but don't know where to find it. I suppose I could use the google, but it looks like you're online now too...

[Leo Van Der Loo]

Nathan I got it at a local chemical supply place, it came in a dry flake and you make your own strength as required, I know that's not much help but that's what I all I have for you, sorry.

[Nathan Hawkes]

No worries. Thanks Leo.

[Reed Gray]

Concentrated lemon juice will also remove metal stains. Much easier to do when the wood is still wet. It also does a fair, but not great job of getting walnut stains off your hands.
robo hippy

[Dick Strauss]

Paul,
If it is ornamental cherry like the stuff I recently turned, the wood will start off pale pink and turn orange almost the color of a carrot as it dries in the paper bag. I assume the color change is from the sap oxidizing but I don't really know for sure. I don't know what the final color might be since my pieces haven't finished drying yet.