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Nostalgia
23rd July 2005, 07:53 AM
The title says it all! I've got a pantload of beautifully spalted birch and I'd like to make some usable bowls for some friends. I'd rather not kill them (the friends). Will Salad Bowl Finish be enough to make these safe? I'd think an epoxy finish would be the be-all-end-all, but I still don't want to give these away and hurt anyone.

Thanks in advance,

-Joe

rsser
23rd July 2005, 08:00 AM
You have to kill the fungus spores. They can cause bad reactions.

Try a mild bleach solution on a test piece. Say 1 to 10 of supermarket bleach. Do it twice allowing it to dry in between.

Nostalgia
23rd July 2005, 08:02 AM
You have to kill the spores. Try a mild bleach solution on a test piece. I had considered that. How do I know if the little buggers are dead? "Honey, could you come here and taste this soup?" :)

Thanks for the advice,

-Joe

rsser
23rd July 2005, 08:15 AM
Pleasure. Bottom line is that you can't be sure (unless your Honey falls to the floor writhing, and you haven't made a joke).

Safest option is not to use it for food utensils.

Lovely stuff spalted birch; got one going by coating it in furry yogurt. It's too dry here to happen naturally.

BTW You need to bleach and scrub it before turning too. You don't want spalted nostrils.

Rowan
23rd July 2005, 10:07 AM
The title says it all! I've got a pantload of beautifully spalted birch and I'd like to make some usable bowls for some friends. I'd rather not kill them (the friends). Will Salad Bowl Finish be enough to make these safe? I'd think an epoxy finish would be the be-all-end-all, but I still don't want to give these away and hurt anyone.

Thanks in advance,

-Joe


Joe Joe Joe you poor misguided fool. Havent you heard about all our new anti terrorist measures. What a risk you are taking, dilberately growing bacteria. As a concerned member of this bulletin board I feel that it is my responsibility to help your out before big brother swoops and puts you in a detention center for say 75 years trying to decide if u are a threat or not.

STEP ONE
Gather up all of your wood that shows any signs of spatling. In fact include any that doesn't just in case.

STEP TWO
Obtain two hazardous material bags. Dont but them as it may arouse suspicion. Best option is to scrounge thru hospital dumpsters for a couple of second hand ones.

STEP THREE
Bag up all the wood not once but twice just to ensure it passes Oz Post inspection and stick an a4 sheet of paper to the outside

STEP FOUR
Place my address on it and post it all to me and I will safely "dispose" of it all :D

rsser
23rd July 2005, 10:40 AM
I'm inspired by Rowan's selfless offer to help with the disposal ... in the name of the transaltantic alliance in the war on biological agents.

And will do some rigorous testing for you, and find that spalted timber is safe under strictly controlled conditions (hehehe).

RETIRED
24th July 2005, 01:21 AM
Microwaving will help kill bugs too. Gently of course. :D

Nostalgia
26th July 2005, 12:55 AM
What a couple of gentlemen! Making such a sacrifice for a guy like me. The wood's already in boxes; where should I ship them? ;)

I'm going to give a bleach solution and Salad Bowl Finish a try. I'll be my own Guinea pig :) Mmmmmm, special soup.

Would you immerse the bowl in the bleach solution for a while or just apply it to the surface? I'm thinking immersion.

Thanks again,

-Joe

rsser
26th July 2005, 08:37 AM
The spalting will be running right through the grain, so yes, immersion might be best. And then some immersion in water several times over to get rid of the bleach. If you've got several pieces do a control test with microwaving as per 's suggestion and before finishing put the bowl in a humid spot and see how soon or whether it restarts spalting.

In both cases I'd be looking for a finish that was more than wipe on. Suggest immersion in any kind of cheap nut or seed-derived oil for a week. Then let it sit for several weeks to harden.

Guess you won't be needing my address now ;-}

Little Festo
26th July 2005, 09:40 AM
Hello Joe,

Can you boil the bowl? Boiling is a supposedly a good method for drying green wood and apparently works well when done properly (I haven't tried this). I believe that care need to be taken when drying, slow drying in a paperbag or in one of the "wollies" cloth shopping bags. I think that the formula is for an hour for each 25mm of wall thickness, but if the wood is dry that might not be crirical. With the green wood you should follow that formular or you may get cracking.

I have read that you may get a slight loss in colour but I imagine that you would also get that when using bleach.

Hope this helps - Peter

rsser
26th July 2005, 11:13 AM
Good point about loss of colour Peter; the spalting-induced colouring might bleed with any kind of soaking

PS He's from Noo Joisy .. may not have Woollies there ;-}

Nostalgia
27th July 2005, 12:14 AM
Nope, no Woollies here :)

I'm not concerned with using it for dry foods like nuts or 'tater chips - I'm sure any finish will be safe enough there. I was wondering about wet/warm foods like rice or soup. I've asked the USDA if they know anything, so when I find out I'll post back here.

I've found a bit of reading on the subject, and of course there are conflicting views. Some feel it's nothing to worry about; we consume all sorts of fungi/molds in our daily routine.

Of course I could limit the use of spalted woods to decorative projects, but I'm a utilitarian kind of guy and like to see my wooden creations fulfill their destiny. That's why I make all wood bows. There's nothing like using something you created with your hands. Besides, I just want to know :)

-Joe

rsser
27th July 2005, 12:38 AM
Yep.

But spalting's a work of (nature's) art. That brings with it its own demands and limitations.

Nostalgia
27th July 2005, 12:38 AM
I had a thought about baking the bowl. I did some research and came up with some encouraging info:


A temperature of 56°C held for 30 minutes (to be heated at the core) is a scientifically-based criterion that has been adopted as a standard to kill most problem organisms (including fungi) in wood packaging material. While this is adequate for the vegetative state of most molds, it is inadequate for complete mold disinfestation if resistant species are present. However it is a practical compromise. Usually the temperature achieved during kiln drying of lumber and especially during pressing of panel products is sufficient to kill molds which may have been in the raw materials.

Growth becomes less rapid as temperatures are increased above 95°F and ceases for most fungi at temperatures slightly in excess of 100°F. Prolonged exposure to temperatures slightly above the maximum for growth, or even short exposure to temperatures much above the maximum, can kill fungus completely.

So I'm thinking that if I bake the bowl for 1/2 hour or so it should be completely sterile when it comes out, as long as it survives the baking process :) I'll keep you posted.

-Joe

PAH1
1st August 2005, 09:42 AM
I had a thought about baking the bowl. I did some research and came up with some encouraging info:




So I'm thinking that if I bake the bowl for 1/2 hour or so it should be completely sterile when it comes out, as long as it survives the baking process :) I'll keep you posted.

-Joe

Joe

I happen top work in the fungal area of scientific research, the bit you are talking about is bacteria and yeasts in food, not the spalting kind. Some fungal spores can survive 500 degrees for a few seconds and hours at 100. The bleach idea might work to kill the spores but that is not really what you are trying to stop, the spores are unlikely to hurt you but the toxins they may have produced could. Seal it properly and make sure it stays that way and you should not have a problem.

reeves
1st August 2005, 04:02 PM
seems like a good hard sand, sanding sealer, a few coats and then the laquer, hard stuff that cures like nirtosulluose or some kind of water based equivilant...

hard seal the whole lot....

cheeeeeeeers
john

Nostalgia
2nd August 2005, 12:47 AM
I happen top work in the fungal area of scientific research, the bit you are talking about is bacteria and yeasts in food, not the spalting kind. Some fungal spores can survive 500 degrees for a few seconds and hours at 100. The bleach idea might work to kill the spores but that is not really what you are trying to stop, the spores are unlikely to hurt you but the toxins they may have produced could. Seal it properly and make sure it stays that way and you should not have a problem. Thanks for the great post! It's nice to have someone who works in the field lend some input.

I didn't think about the toxins the mold would have created. That's a great point. I think I'll limit the spalted wood to dry contents. For a sanding sealer I'm going to try CA - that should be a pretty durable base.

Thanks again for all the great replies! This is the first in-depth discussion I've been able to find about spalting. I'm still waiting for the USDA to get back to me on it. I'm not holding my breath :)

-Joe

Big Joe-USA
13th August 2005, 12:15 AM
Thanks for the great post! It's nice to have someone who works in the field lend some input.

I didn't think about the toxins the mold would have created. That's a great point. I think I'll limit the spalted wood to dry contents. For a sanding sealer I'm going to try CA - that should be a pretty durable base.

Thanks again for all the great replies! This is the first in-depth discussion I've been able to find about spalting. I'm still waiting for the USDA to get back to me on it. I'm not holding my breath :)

-Joe

I HOPE your holding your breath, or at least wearing a good mask. You don't want that spalting to get into your lungs. They provide a great habitat for mold,.... dark, damp, & warm. The first time I turned spalted wood I didn't have a mask and was hacking for a week. Be careful!!

Joe