I do woodturning in a community shop (maker space) and it turns out they have a policy against (or at least highly discourage) using green wood in the shop due to the possibility of mold growth in the dust collection system and shop vacuums.

I only discovered this policy after turning a couple of bowls from a branch of maple which came down in my yard after a storm. The shop lead says I might be able to turn green wood if I use a broom rather than a shop vac to clean up the shavings. Turning these first few green bowls was fun and the branch which came down was huge so I have a lot of wood.

Is there anything I can do to assuage these concerns about mold growth (aside from letting the wood dry for a couple of years)?

I'm new to woodturning and wood shops in general so this is the first I have heard about the mold issue and my internet searches have turned up almost nothing about turning green wood and mold.

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    Don't they empty their shavings periodically? (Sorry -- not productive, but this just isn't something I've ever heard of as a concern. And a lot of folks are turning green wood because that's a good thing, so you'd expect more of an outcry if mold was a thing.) Aug 23, 2023 at 14:00
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    There's nothing you can (and IMO should) try to do to change their minds about this because their concerns are legitimate. Green wood often has bark attached, and bark can house an enormous number of moulds, many of them (of course) wood-eaters. Green wood is also incredibly wet, and by introducing wet wood into the system you increase the humidity many-fold. Plus the shavings, flakes etc. are just plain sticky and cohesive!
    – Graphus
    Aug 23, 2023 at 14:12

1 Answer 1


This just seems a little nuts to me. Even the wettest wood that will spray you with moisture as you turn it isn't going to make that much difference in a large dust collection system. and if it's heavily used (the dust collector) it really wouldn't be much of an issue, between the relatively low volume of material you are putting in there and how often it is emptied. If it is 'reasonably' dry like you didn't cut it down yesterday and have kept it out of the rain for a week or so, it REALLY shouldn't make much difference.

Now having said that, Green turning also tend to make large easy to clean up piles of shavings and very low 'dust'. So just letting it all hit the floor and sweeping it up later also shouldn't be a big deal, as long as they have a place for you to put them after you are done.

Honestly, if they have metal ducting, I'd be more worried about very wet turning causing rust than any mold.

  • I'm going to go ahead and upvote this, partly because nobody else has bothered to! (Our perennial problem with people forgetting to/neglecting to vote.) But I do have reservations; in addition to the things in my Comment above, bringing in un-dried wood to a communal shop runs a high risk of introducing wood-borers to the space, since they naturally occur in the wild and often begin their life cycle in the bark before burrowing into the sapwood. Irrespective of this, IF they did allow it under limited circumstances I would suggest they simply turn off dust extraction and forbid the dust vac.
    – Graphus
    Aug 25, 2023 at 6:01
  • @Graphus true that is something to think about, though different from the question. But in general there are 2 kinds of wood borers, those that like the fresh (Cambium) and those that like the 'dead' hartwood. The fresh ones are going to generally die as the bark comes off and they don't have the moisture they need to survive, (and nothing in the shop should sustain them) and the others generally need to be killed with a hard freeze or kiln drying. (and often get cut up during turning), neither have a great chance of spreading. Though I'm sure there are a few little bugs that might.
    – bowlturner
    Aug 25, 2023 at 17:43

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