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Help! - Mildew

K

KEW

Joined
Jun 9, 2005
Messages
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Location
North Metro Atlanta
I plastic bagged a very wet project last night (until I got home from work today) to keep it from splitting. It worked, but I also got some small spots of mildew. It would look better without the spots.
Is there a way to get rid of the mildew without bleaching the figure in the wood.
The wood was given to me as apple. Maybe crabapple or some other variation.
Thanks!
 
Howdy KEW.......

There is a related thread that dealt with mildew that had discussion previously.

Here's a link:

http://www.aawforum.org/vbforum/showthread.php?t=4543

There were two methods of dealing with mildew in that thread......lemon juice and TSP solution. I tried the lemon juice with unsatisfactory results. I think either method will require "full coverage" of your turning surface in order for it to look right......but, I do have a limited amount of experience dealing with mildew issues, so take that for what it's worth.

The bowl I talked about in that thread was saved by returning it to the lathe and taking a small amount of wood off the surface. I couldn't say one way, or the other if mildew typically is only on the surface, but it was in my case.

The next time I have a mildew problem, the first thing I'll try is taking off a little surface wood first. I couldn't say for sure, but my thoughts are that it might be advisable to allow your turning some drying time before taking off a layer to remove the mildew......If you do that now, you just might get the mildew back tomorrow!

otis of cologne
 
Thanks Odie,
I'll read through the other thread, but I wonder if I can sand through it after it dries. I can only wait and see, but I turned it in face grain orientation, so it may go too far out of round to be able to clean up with a gouge.
 
I read through the thread and I'll probably give the lemon juice a shot first. Unless things go berserk in a PAPER bag tonight, I only had occasional gray spots around 1/16 diameter. They are only on light wood (at least that stand out) so the lemon juice stains might not be too conspicuous.
Thanks again for the help!
 
Are you sure you want to get rid of the mildew? Many of our woods in Hawaii are very plain so we put them into plastic bags for up to several months. Once you turn the piece and the air hits it the spalting stops and the timber can really gain some character.
 
Mildew

Kurt
I rough turned a box elder bowl recently, and put it in a plastic bag overnight, with the resulting green mildew. Good old household bleach poured right on the green, with a little toothbrush action, with a clear rinse, cleaned it off very easily. I wasn't particularly worried about bleaching the piece too much, because I will be finish turning it at a later date. Might be worth trying.
Kurt
 
I think the household bleach might be worth trying. It does not do a good job of bleaching wood but might be strong enough to clean that off. I think the spot application would do little if any color change and the toothbrush afterwords would help blend any change into the background.
One application of regular wood bleach doesn't change wood color very much, it takes several coats. This is why I think the above might work. You could apply it with the tip of a brush or break the end off of a tootpick and dip in in the bleach. That would allow a very precise application.
 
Milldew

John,
I guess I worded my post incorrectly. I poured the bleach all over the bowl, so that it was uniformly wet, then used the toothbrush on the spots. After the scrubbing, I rinsed the entire bowl. I figured that the dousing would eliminate any problems with the bleach just being used in spots. Seems to have worked OK.
Kurt
 
The science boys say that you need to get <16% to stop mildew, which I believe, based on strictly unlogged observation. Since the loss of unbound moisture does not result in fiber shrinkage, I like the suggestion to blast with compressed air. Clears a lot out of the way. I figure the closer I start to 30% the sooner I get <16%. After that, open air rather than bags until the end gain looks dry.

If you're going for short-term storage, I'd drop the temperature as the preferred mildew prevention measure.
 
Thanks all!

This is the most interesting wood I've yet had on my lathe, albeit, having a crack before I started. It may be a lost cause, but I'm in it for the challenge & education!

I peeked at it this morning, and the mildew doesn't look much worse from being in a "loosely" closed paper bag overnight. It is a natural edge, face-grain hollow form and the top half is down to 1/8-3/16" (which is final thickness), but the bottom half gets up to 3/8". I will finish the bottom half tonight, then I'll run the speed up and throw some of the free water.
Bleach is probably the best approach as I would expect it to continue to suppress mildew growth after cleaning off what is there

CaptJim,
The mildew I am getting is not what I would look for as spalting. It is more like dirty smears (though very small at present). I don't know what differentiates between nice distinct lines and the smear effect. The areas of light wood have curly-figure.

MM,
How does wood dry in the fridge? Would I bag it? This is probably 4.5" diameter by 5.5" high, so I can fit it in. I should have done this the last 2 evenings.
 
KEW said:
MM,
How does wood dry in the fridge? Would I bag it? This is probably 4.5" diameter by 5.5" high, so I can fit it in. I should have done this the last 2 evenings.
Click to expand...

Wood can be dried in a frost-free fridge or freezer, but it's nothing you would normally want to bother with. What you're after in short-term storage is a temperature below about 50F where mildew doesn't grow. You could bag it without worries in plastic under those circumstances to keep it at the FSP for ease of working. You've already discovered what keeping it warm and damp can lead to.

Frost-free types warm periodically to discharge excess moisture, so introducing more in the form of wet wood isn't really desirable. If you had an old fridge and were flush with energy money you could use the built-in timer to actually dry your stuff, though I wouldn't. http://www.howstuffworks.com/question144.htm

This so-called "freeze drying" method is one of many things which crop up periodically in forums, but it's really about humidity control, like all drying methods. Now if there were an actual humidistat control, might be worth trying.
 
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