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Has anyone solved this problem?

J

John Shillabeer

Joined
Dec 21, 2014
Messages
25
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Location
Nanaimo BC Canada
A friend recently gave me my pick of a very large, big leaf maple: a beautiful old tree some 7 ft diameter at the base.
So far, every piece that I have turned shows these grey spots. The are barely visible when the wood is full of sap but they become much more noticeable as the surface dries. The photo shows a bowl turned when green and since dried to 11-12% moisture. If you were to look inside the bowl,you would see the same pattern of grey patches there too.

I suspect that the whole trunk is like this.

One fellow turner suggested that this might be staining from excess iron. But we have lots of BLM in our area and this is the first time I have seen these grey spots.

I have been experimenting with different blends of Chestnut spirit stains (aiming for a sort of dark red wine look) to hide the grey patches, but so far the results have been disappointing.

This problem is new to me, but perhaps members have dealt with it before. Advice and suggestions would be very welcome..

Thanks

JohnDSCN0019_01.JPG
 
We, unfortunately, don't have BLM here, but my guess would be either blue stain or mold. (You are welcome to send me a couple half logs to experiment with a way to deal with the gray. :D)

Oxalic acid will remove the gray from weathered wood, but this ain't that so it probably won't work. Two part bleach consisting of sodium hydroxide (lye) and industrial strength (30%) hydrogen peroxide will bleach the color out of wood, but probably won't touch the gray. The natural color of the wood might be altering the color of the dye too much. I think that I would try bleaching the wood white with two part bleach and then try a royal blue Chestnut dye. If I'm not mistaken, the gray areas would just result in a slightly darker blue.
 
Maybe it's just me, but I don't find that unattractive. It's just something that Mother Nature has provided in it's unique aspect. If it were me, I'd just go with it......:D

-----odie-----
 
I have very little experience with BLM.
Agree with Bill blue stain or mold.

I think a color is your best remedy. Bleach has has not worked for me on holly Blue stain or mold.

If the Blue dye does not produce a pleasing result. Black Leather dye will give you a uniform consistent black.
The shape and rim treatment are the feature of the bowl.
Both will look great in black.

Another possibility is to use coats of different color milk paint on the bowl,cut I back tomshow multiple colors. colored milk paint on the rim the black milk paint let dry (heat gun or hair dryer speed it up) then scotch bright on on the rim. Scotch bright removes the black from the high spots enphasing the pattern with the underlying color and maybe some bare wood.
 
I agree with Odie, it is what it is.

You can use mineral spirits now to get an idea of what it will look like with a clear coat.

When the bowl is dry and ready for its second turning you can try some surface coat finishing ideas on test spots. Since you will be turning off that layer of wood it's like a free test piece. It you have a lot of thickness to remove you may even be able to try bleach or dye if you've decided to go that route.
 
Leave it as part of the wood. Show some photos of the finished turning. Thanks for the question. Can't help even though I stayed at a Holiday Inn Express.
 
How are you drying the blanks after the rough turning. If you are packing all of them in a bag with chips, that is likely when the mold is starting. Try a new technique, don't use the chips. The trunk is really 7' across? How are earth do you get blanks from that? I'd like to see a picture of that log!
 
Richard Coers said:
The trunk is really 7' across? How are earth do you get blanks from that?
Click to expand...

This is only for very experienced chainsaw users. No tractor required.
You can use a plunge cut aka boring cut to rip the face of a blank a few inches less wide than your bar then cross cut the ends. Or three plunge cuts to rip a tee inside the log then cross cut two were shaped blanks,

Also there is Stihl with a 4 ft bar hanging in in our Ace hardware store didn’t check the price tag.
Need a tractor.
 
I've read theories that mold, if it is indeed the cause, requires three things to form:
1. Presence of active mold spores.
2. High moisture content on the surface of the wood.
3. Presence of "food" for the mold within the wood.
​
Kind of like the "fire triangle" where all three of these are needed for a fire to start: fuel, oxygen, ignition source. Strategies for fighting/preventing fires involve removing one or more of the legs of the fire triangle. Similarly, you could try removing one or more of the legs of the "mold triangle" to prevent the mold from forming.

Here are some random thoughts, many of which I have not tried, so I won't claim experience that they will work.

1. Get rid of or neutralize mold spores.
  • Seems like they are always present.
  • Some people have tried spraying the surface of bowls with bleach after completing the rough turning. I've heard this is not very effective.
  • Some people make a solution of boric acid and spray it on the surface after completing rough turn. I've read that this is more effective. I've been leery of trying this myself due to concerns with breathing the residual boric acid with doing the 2nd turning of the dried bowl blank.
  • There are also products sold specifically for preventing mold on wood. Bora Care with Mold Care is one that has high praise but is crazy expensive: https://www.amazon.com/Bora-Care®-M...542725932&sr=8-1&keywords=bora+care+mold+care
2. Prevent high moisture levels on the surface of the wood while drying
  • Is the wood wet enough that it's slinging water when you turn it? If so, once you have the bowl rough turned, stand out of the way and turn up the rpm. Let the bowl spin for a while until the free water stops coming out.
  • Dry in a paper bag. At first the bag will get very damp. Change it every day to a new dry bag. I just throw the damp bag on the floor and it will be dry enough to use again on the following day.
  • Don't use chips in the bag as mentioned earlier.
  • Put the bowl in bag on a wire rack, ideally with lots of air below it. Don't rest it on a solid surface.
3. Avoid using wood containing lots of bug food.
  • Next time, convince your friend to cut the tree in November or December when it is dormant and there is less sugar present in the wood for the mold to munch on.
#3 is the one I've found to be most helpful to making maple bowls that stay white instead of discoloring.

Dave
 
hockenbery said:
This is only for very experienced chainsaw users. No tractor required.
You can use a plunge cut aka boring cut to rip the face of a blank a few inches less wide than your bar then cross cut the ends. Or three plunge cuts to rip a tee inside the log then cross cut two were shaped blanks,

Also there is Stihl with a 4 ft bar hanging in in our Ace hardware store didn’t check the price tag.
Need a tractor.
Click to expand...
I've handled some really large urban logs around here, and I bought a Husqvarna 3120XP about 10 years ago. 119cc, 8.3hp. Darned thing sounds like a dirt bike when running. Hook in the bucking teeth and pull on the handle with both hands. It's one heck of a machine!
 

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Richard Coers said:
I've handled some really large urban logs around here, and I bought a Husqvarna 3120XP about 10 years ago. 119cc, 8.3hp. Darned thing sounds like a dirt bike when running. Hook in the bucking teeth and pull on the handle with both hands. It's one heck of a machine!
Click to expand...
Knew you had a big saw.

Our turning club had a field trip meeting at Hearn Hardwood many years ago.
One of the things we saw ( a first for Hearn too) was his Amish neighbors splitting a 5+ diameter log about 10 ft long so Hearn could get it on his band saw mill.
The Amish made a plunge cut in the top center of the log, Stuffed a fuse to the bottom of the hole, Poured in a slurpy cup full of powder, tamped in a rag, lit the fuse, and took shelter behind a bull dozer. There was a medium loud bang, a puff of smoke, a dramatic pause and then the two halves of the log unfolded.
 
That type of coloration is some what common in old woods, especially BLM. I would leave it and call it natural, in part because it is and in part because it isn't worth the extra work to 'fix' it. No idea what staining or coloring the wood would do to the color.

As for a chainsaw to go through a 7 foot BLM, one of them that size and age most likely had no insides left to it and 3 to maybe 12 inches of live wood on the outside of the tree. The branches can be spectacular though. It does rot quickly...

robo hippy
 
Thanks to everyone for your ideas. Its amazing and very pleasing that I have received so many answers within a few hours of posting. And No, nice try, but I wont be posting any logs around north America.
I must admit to not being very keen on using industrial scale bleach: I am more likely to get bleached than the wood!
However an experiment with blue dye would be easy.. Also, I have been ruminating for some time about trying my hand with milk paint on a bowl or two. It just seems a shame to obscure the grain.
As for the chain saw issue: the tree was felled by professionals and by the time I was invited to visit and take my pick, the guys had already sliced the trunk into a series of logs. Each is about 10 -11 inches thick. Many had also been cut on a diameter so that they could be manhandled. Nevertheless they were **** heavy! Robo was right. A good part of the lower section of the trunk was hollow.
In a way its a shame that the loggers cut the slices so thin because that of course limits the size of any bowl or platter. I generally avoid end grain unless there is something special about the grain to recommend it.

Thanks again for your ideas and suggestions.
John
 
Too bad that the tree service people weren't woodturners so that they would appreciate the proper way to cut logs. :D

I suspect that the blue dye combined with the natural yellowish tan of the wood will result in green. I think that the two part bleach is available in small quantities at big box stores. I believe that one brand is Kleen Strip.
 
Bill:
Thanks for the tip about the bleach. Idont remember seeing Kleen Strip here in Canada but will take another look. Also I'll ask at my local club about what bleach is available locally.
cheers
John
 
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