Is there any danger in using a spalted wood for, say a salad bowl? If so is there any finish that would neutralize any danger?
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I don't know if anyone knows for sure. It seems that the problem with the fungus that causes spalting is not direct toxicity but allergy to the spores and/or volatile compounds produce by the fungus as it goes about its daily life. (This is the same problem as with the "toxic black mold" that you hear about in houses.) So, a finished bowl shouldn't pose much of an issue, since the fungus is long dead, and even under the worst circumstances of dinnerware abuse there aren't going to be many spores floating around.
So, while spalted wood seems safe for this application (and I've certainly seen plenty of spoons, bowls, cutting/serving boards, etc. made of spalted wood), I don't think anyone can give you a guarantee. Living organisms produce thousands of chemicals, and we're a long way from knowing what most of them are, let alone what physiological effects they might have on humans.
-Steve
Thanks for the response. My guess was that with dry wood that any spores would long ago have become inactive. It is reassuring to know that many serving utensils, etc are made with spalted lumber. Either it is safe or I will get in line and make the same mistakes all over again. If I use a durable enough finish I can hopefully block any potential allergic reactions. Thanks again.Chri7s
I personally would not be concerned. The molds that cause spalting are around us all the time (at least in my neck of the woods, the Great Northwest). They not active when the wood's moisture content is below 20%. No info in your profile as to your geographical location, but unless you're in the swamps of Florida, you should be safe, LOL.
For more info, here a link to Jon Arno's post on spalting wood. One cautionary note: Wear a respirator, and long sleeves when working spalted wood. It can really rev up your immune system, and breathing it is seriously not a good thing.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
forestgirl,
I'm curious about your comment, but unless you're in the swamps of Florida, you should be safe, with regard to spalted wood. Can high humidity affect the spalting even though it might be considered dormant?
It would seem to me that any spalted wood needs a durable finish.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
The wood's moisture content has to be above about 20% for spalting and other forms of wood decay to occur. Unless the wood is in direct ground contact (or is otherwise constantly supplied with moisture), it's difficult to find suitable environmental conditions that allow the moisture content to be that high. About the only place it will happen is in extremely humid, tropical climates.
-Steve
Hi Steve,
I understand the conditions for spalting, well at least I think I do. I was curious to know if spalted wood can be revitalized/revived with high humidity to spalt even more?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
As forestgirl mentioned, the spores are all around us. No matter what the condition of the wood at the outset, if you place it in the right environment, a fungus infestation will begin. As for "revitalizing" an existing infestation after the wood has been dried, I think it's a pretty good bet than unlike the parrot, any actual fungus organisms in the wood are reliably dead, and not just stunned. There may be spores hanging around, not in the wood itself but in any nooks and crannies, and those might jump start the infestation, but it would still technically be a new infestation, rather than a continuation of the old one.
-Steve
Steve,
The reason for all the questions is that I have an experimental log that I'm using to see if I can get it to spalt. It's a barm of gilead (sp?) that came down in a wind storm. It lays on sort of a loam and gravel area and I turn it over every week or so.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
I have a spalt farm, too. I've read that if you bury the log in fallen leaves it helps keep the moisture level up.
-Steve
Bob, please read the link I provided to the late Jon Arno's post on spalting. My comment was a overstated reflection of something in that post. The gist being that unless you live in an extreeeeeeemly humid environment, once your lumber is dried, it will not approach a humidity levelthat will reinvigorate the spores.
This is the second time this week the subject has come up and it comes up several times a year, so I think I'll find the other information he sent me via email years ago and make a web page. Then there will be a link to his wisdom vis a vis spalting. Oh, Jon, we miss you!
If you'd like to know more about Jon, Google him or even better, search his name at FWW.com
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Edited 6/4/2008 12:44 pm by forestgirl
forestgirl,
Yes I hear ya. I did the searches you recommend and found lots from Jon and others as well as the WEB. By the way if one wants some entertainment a search for Jons posts here in Knots is something to behold!
As I told Steve, I'm doing a little experiment to see if I can get a balm of gilead (poplar type wood) log to spalt for me. We've been in Monsoon season up here laetly and from Jon described somewhere (don't recall where) we are having conducive conditions for it. Can't wait to see how it comes out.
Yes I most certainly will post pics if it works!
An old timer told me he thinks that the spores attack the soft part of the growth rings first.
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 6/4/2008 1:10 pm ET by KiddervilleAcres
I am afraid that there is a certain degree of confusion between the " allergic" potential of the spores and the "infective" potential. The allergic properties would always be present in the spore coat whether the spore itself is viable or not. Inhalation or ingestion of the dead spores could still trigger an allergic response. Whether any of the spores in the spalting are still viable is another issue that would require more careful analysis. I would not be surprised, though without any direct personal data, that there might still be some active spores withing the wood. The whole reason for sporulation is to allow the organism to survive harsh, non-viable conditions for long periods of time before being reactivated. I personally would not use any spalted wood in things that would be used with food, particularly if there was a possibility of scrapping, chipping, etc. the piece.
Edited 6/4/2008 3:56 pm ET by dherzig
Edited 6/4/2008 3:57 pm ET by dherzig
"The allergic properties would always be present in the spore coat wether the spore itself is viable or not."
Very true. I don't think there was anything said to suggest otherwise.
"The whole reason for sporilation is to allow the organism to survive harsh, non-viable conditions for long periods of time."
No, the "whole reason" for sporulation is reproduction and dispersal. (You may be thinking of bacterial "spores," which aren't true spores, and serve a different function from fungal spores.) It's true that spores tend to be relatively hardy, but that's also frequently true of seeds, eggs and other reproductive/dispersal mechanisms.
In any event, the point I was trying to get across is that there aren't going to be any spores in the wood; that is, in the actual cellular structure of the wood. There would be no point for the organism to produce such spores; after all, it's all about dispersal. But there may indeed be a relatively high concentration of spores on the outer wood surfaces, nooks and crannies, etc. My last post to Bob referred to these, in the context of "reinfecting" the wood (since that's what he was looking to do), not in the context of food safety. That said, the production of a cutting board, utensil, etc. would normally involve cutting away any of the wood surfaces that would tend to harbor spores, so I believe that the likelihood of spores being present in such a piece is still quite low, comparable to the endemic background level of spores in the environment.
-Steve
I don't know but I'd wonder if spalted wood was kind of weak or too soft. Anyone know?
Denny
It can be.
I personally wouldn't use spalted wood for food service (at most perhaps as a fruit bowl). I'd turn the bowl and use it as an art piece - display it on top of another piece I'd built or something along those lines.
Spalted wood needs a film finish to arrest the decay. Film finishes and salad bowls are not an appropriate mix IMO.
"Spalted wood needs a film finish to arrest the decay." In reality, it needs nothing more than to be dried to "arrest the decay" and then kept in a relatively dry environment. My boards have been sitting on the lumber rack in my shop, where humidty varies from about 25% to 55% through the year, for 4 years and have shown no advancement of "decay".
I've not researched much on the finishing of spalted maple, but enough to know that some people use shellac, some oil, and some lacquer. I was intrigued to see how many spalted-maple guitar bodies showed up! Gotta go back and take a look at some of those.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
A film finish will stop the advance, period. It's sure-fire. Keeping the wood dry, however, is not.
I don't believe spalted wood is appropriate in a food service application.
Salads are not dry. Hopefully, the greens will have been washed thoroughly and of course will retain some of that moisture as well as the moisture in the vegegation itself.
You might recall that the OP was asking about spalted wood for salad bowls.
Edited 6/4/2008 4:35 pm ET by TaunTonMacoute
It can be, but isn't necessarily. I just cut down a standing dead red maple. There's a fair amount of spalting, and a fair amount of soft, punky wood. But the area of spalting and the area of punkiness don't completely correspond, which leads me to believe that whatever decay mechanism causes the punkiness (I think it's what's known as "white rot" fungus, but I don't really know for sure) isn't the same as the fungus that causes spalting.
-Steve
Yes, makes me wonder if spalting and rotting are just different degrees of the same thing.
Denny
Punkiness varies from one piece of wood to another depending on how far gone it is. I seem to remember that people who work with spalted wood will sometimes apply a solution that soak in and helps "buck it up" (my caffein-deprived phrase). Also, you could design around the spalting. For instance, if you were making serving spoon and fork for salad, you might lay it out such than the thinnest parts avoided the most spalted parts if they happened to be quite soft.
I have two nice pieces of spalted maple that were given to me, but unfortunately they're flat, not made for turning but for slat stock. doors to a jewelery box perhaps.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
I haven't worked with it. Seen and handled it, but that's about it.
Denny
From the experience I've had turning it the biggest problem aside form the fact that some parts of the wood can be so rotted as to virtually disintegrate, the degree of hardness or softness varies and when sanding on the lathe, the piece can get significantly out of round or develop relative divots, where the soft spots were differentially sanded deper than the hard spots. I would try to sand as little as possible.
Regarding the death of the spores, I am not a microbiologist, but there have been fungal spores as well as various seeds extracted from ancient Egyptian tombs that are still viable. When sanding this stuff it becomes aerosolized and inhaled and who knows what it will do in your nice moist warm bronchioles. Extra caution as far as vacuum extraction of dust and respirators seems prudent.
Jay
That's what I suspected. Thanks, Jay.
Denny
thanks to all for the in depth discussion. I was away a few days and was delighted to see the extent of information shared. I really appreciate all of the information. Thanks again,Chri7s
blewcrowe, here's some information on spalting, and its effect on strength. After the general guff about spalting you'll find some information at the end about structural degradation and my opinion about the potential loss of strength. Slainte.
An infection by two or more white rots causes spalting in a variety of woods. The fungi infect felled damp logs and planks as well as dead sections of living trees, shrubs and bushes. Spalting is particularly noticeable and prized in light coloured timbers such as maples and beech, as mentioned earlier. I’ve also seen it in several dark woods such as cherry, elm, walnut and oak. The variegated colour is visible in dark woods, but it’s not so obvious and I don’t generally find it so attractive which of course is my personal taste. The different fungi attacking the wood cause different changes in colour and cause varying degrees and types of degradation. In effect these different fungi set up defined territories within the log or board. The black lines mark the edge of the territory each fungus has staked out for itself—it’s a defensive line that other fungi can’t cross.
Some sawmills deliberately leave felled logs out in the wet to encourage spalting. Beech is a favourite for this, although choosing the right moment to convert the logs into boards requires skill and knowledge—too early and the spalting won't be advanced enough, and too late means the wood is too soft and rotten to be of any real use.
There is quite a long of history of woodworkers inducing spalting, and with some success. Storing a partly turned bowl in a sealed plastic bag in a warm spot along with some water can do it. Burying your wooden creation in damp sawdust for about three quarters of a year is another method. I’ve seen discussions in woodworking forums on the internet in which woodworkers describe various blends of fresh and partially decayed organic matter and things like fertiliser all mixed together. This soup usually ends up in a tightly sealed plastic bag along with the workpiece, warmth, and perhaps some extra water to make sure there’s plenty of moisture for whatever fungi decide to grow. Judging just when to remove the workpiece from the artificial setting is the most difficult task, but the fungi do establish themselves quite readily.
Degradation of the whiter zones in the attached photo is quite severe. I could easily make a dent in these patches by simply pressing in a fingernail. The darker zones are still quite firm.
The piece of spalted European beech above measured 12% MC with my pin type moisture meter. Its size was 15.5” X 8” X 0.625” or 0.045 ft³ and weighed 1.516 lbs. Dry European beech at 10% MC normally weighs approximately 45 lbs per cubic foot, so an uninfected piece this size should weigh about 2.025 lbs. The sample above weighed about half a pound less than a similar uninfected piece. This gives a rough indication of how much of the wood’s structure was destroyed by the spalting fungi, that is, approximately 25%. I would definitely be wary of using any spalted wood this much lighter than uninfected wood for load bearing or structural parts.
Richard Jones Furniture
Interesting. It's a very pretty piece, isn't it? Almost looks painted.
Denny
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