Bowl With Black Mold

[Flute Maker]

I have a piece of spalted dogwood that has been sort of troublesome.It had cracked some after turning and letting dry.The guy I got it from said he had in the past had some to crack and he mist them with water and the crack would close back up.(he was a more experienced turner than I am) I did that but then ....this was a whileeeeee afterwards I noticed the bowl had what appeared to be black mold on it.What is the best/safest way to get rid of this with out making a lot of dust? Thanks!!!


After I get rid of this and finish shaping etc I will fill what cracks are there with some sort of inlay and then sand and finish.

 

[Gofor]

Not a turner, but to remove the mold (if it is possible)without generating a lot of dust, I would go with a freshly sharpened card scraper. You will need to scrape "down the grain" whenever possible, which can be problematic securing work like a bowl while scraping. I have found a router mat or some non-slip shelf liner (looks like this https://www.dollartree.com/black-non-slip-shelf-liners-60in-rolls/205932 ) is good for keeping items from sliding around on a smooth bench top, and may work as you change directions on the bowl. The shelf liner is a lot cheaper than a router mat, and is available at Lowes, Walmart, and many of the "dollar" stores. I personally haven't had a lot of luck removing black mold from raw wood with chemical solutions.

 

[Willemjm]

I don’t believe the water will close that crack. When we turn wet wood, we normally mist with a spray so the wood does not dry too fast while on the lathe. After that we put it in a paper bag with sawdust to dry real slow.

I close cracks with fine sawdust pushed in or over the crack and wet it with CA glue. Then turn the lump of CA/sawdust on the lathe back in shape.

To remove the mold, I would put it back in the lathe and either sand or remove a thin layer of wood with a turning tool.

 

[Flute Maker]

They did close buttttt after a period of time they would open back up...Yeah I am going to do some ca glue and fill with sawdust or turquoise inlay ..Just thinking for now!!

 

[Roy G]

Mike, is this blank partially turned? How are you drying it? If you are going to final turn it after it finishes drying, you can take the mold off then. I would follow Willems suggestion and fill the crack before final turning. Of course, you have to be realistic about how the crack affects the final bowl. Sometimes you have to consign your work to the fireplace. And then go on and make another one.

Roy G

 

[JonB]

You can just turn away the mold on the bowl if you can salvage it with the crack. Spalting is essentially mold that runs through the wood.
Even if the crack "closes up" after spraying with water, the crack will still be there and should be treated as a weak point in the roughed out bowl. Cracked bowl blanks must be treated with caution. If the crack runs through the rim then the bowl could come apart on the lathe when trying to finish turn, even if you try to flood it with CA glue and shavings. Cracks come from stresses in the wood as the bowl blank dries, some blanks will crack no matter what you do. There are many methods of drying rough bowl turnings, some work better than others but spraying water on a bowl won't solve any problem.
Most turners figure there is a rate of loss to cracking on all roughed out bowl blanks, you can't save them all.

 

[Mike Mills]

Around my house I use a 25% bleach solution (sidewalks, etc) for black mold. I think that is a higher % that Dr. Spalt recommends to halt spalting.
For wood I would mix a 10% solution in a spray bottle and give it a light spritz. If it isn't gone in 30 minutes add about 5% more bleach.
Only the very outside is be discolored and will turn or sand away. Only a very light spray is necessary, not dripping.