High "MC".....To turn, or not to turn......that is the question!

[Odie]

Normally, any wood I receive that is above 20 o/o moisture content is roughed out and anchorsealed right away. My basic reasoning for this is an effort to control the introduction of mold/mildew. Wood that is below 20 percent MC, I'm not in such a hurry to rough out the bowl.........

There are some roughed bowls that do show mildew after it's roughed out, but I can't conclude that the mildew wasn't already a factor prior to my roughing it........😕

Wood that is below that 20 o/o MC point, doesn't seem to be in much jeopardy of generating mildew.....that is, unless it was there all along. That is a consideration that seems not to have a definitive conclusion.........?

With bowls that do develop a mildew, I've found that it's pretty much limited to the surface.......that is, IF it's dealt with it in a timely manner. The solution has been to return the roughed bowl to the lathe, take down the surface a bit, and re-anchorseal. When the moisture content is low enough, the mildew does not return. The magic number seems to be somewhere around 20 o/o MC, where mildew will not return where it once was.

.....Was just wondering what formula, thoughts on this by other turners might be. Do you hold off on roughing certain bowl blocks, and if you do, what is the reason? There may be more to the reasoning than mildew considerations. It's certain that the higher the MC, the more warp there will be (or, is possible)......but, the species and grain orientation aspects of certain specific examples of wood are a strong indicator of the amount of warp one will get, too..........

ooc

 

[MichaelMouse]

You don't cut your sections long enough? Is that the reason you worry about mildew on something you haven't even turned? I always trim the ends before the bandsaw, so it's not a player. I turn what I have based on what I want. Prettiest and largest first.

I think the FPL lists 16% as the lower limit for mold growth, but mildew can grow on a surface that's otherwise dry but picks up a day or two of rain. Doesn't even have to be organic.

 

[Odie]

You don't cut your sections long enough? Is that the reason you worry about mildew on something you haven't even turned? I always trim the ends before the bandsaw, so it's not a player.

As usual, you are assuming things that are not correct, MM.........🙄

I purchase virtually all my wood. They are pre-cut into bowl blocks and shipped to me. As the cost of shipping is a major factor, they normally do not have much excess........

.....Now, back to the subject at hand..........😀

I turn what I have based on what I want. Prettiest and largest first.

I think the FPL lists 16% as the lower limit for mold growth, but mildew can grow on a surface that's otherwise dry but picks up a day or two of rain. Doesn't even have to be organic.

The 16 o/o figure would seem to be close to my personal calculations on this. There is no rain in my shop, so that isn't a factor for me.....but a good comment none-the-less, as it may apply to a few other turners.


ooc

 

[MichaelMouse]

As usual, you are assuming things that are not correct, MM.........🙄

A QUESTION - note the punctuation - is NOT a presumption. The quote above, a declarative, makes a presumption. Nothing new with you, however. With so little information given - like buying precuts - one has to do a little fill-in or ask for more information. So, for all the others who roll their own, leave an extra couple inches to cut away nasty. For OD, if you buy blanks, don't buy them so wet that you worry about mold, if mold bothers you.

 

[William Hutchinson]

Speaking with all of 1 1/2 years experience, I've dispensed with rough turning. Projects are turned to final thickness using the methods John Jordan ascribes in "The Aesthetics & Properties of Wood." This method assumes that the blank is correctly cut in relationship to grain and pith orientations. Drying time, mildew formation and distortion are minimal. I’m with MM and leave the tree section whole and trim checks/defects prior to use.

Currently I only use local timbers which can be obtained with little or no cost. These two forms below were turned start to finish with freshly cut wood. The drying time in a closed cabinet was three/four days.

*What I failed to mention is using compressed air to blow the moisture out of the turning greatly enhances the dry time.

 

[hockenbery]

I mostly turn HFs like William above, they are finished turned in on step.
I can' remember the last time one grew mold and they dry to sand in 3 days.

I like to turn wet wood as soon as I can.
I turn a few bowls that I dry and return. No anchor seal it takes too long to dry. I dry them in paper bags.
These do get mold occasionally. Especially if I forget to swap the bags every day for the first 5 days.

I wipe the mold and surrounding surface with clorox. It kills the mold.
Will Clorox work with anchor seal? It might. Sure be a lot less time than turning away.
A chlorox wipe before you anchor seal would kill mold in a suspect piece.

Mold is everywhere so ensuring a mold free blank is not possible.
Have fun,Al

 

[Odie]

Wow......to read this thread, you'd think the process of seasoning bowl blanks is no longer necessary! ......that is, if I'm reading this right!

Well, I guess I'll continue to do what the turners of past have been doing all along! 😀

ooc

 

[hughie]

[Normally, any wood I receive that is above 20 o/o moisture content is roughed out and anchorsealed right away. My basic reasoning for this is an effort to control the introduction of mold/mildew. Wood that is below 20 percent MC, I'm not in such a hurry to rough out the bowl.........

For me at my location thats goes for wet wood.

There are some roughed bowls that do show mildew after it's roughed out, but I can't conclude that the mildew wasn't already a factor prior to my roughing it........😕

Yeah I find the same but I dont worry too much about as come summer and the much dryer air. This takes care of any mildew etc.

Wood that is below that 20 o/o MC point, doesn't seem to be in much jeopardy of generating mildew.....that is, unless it was there all along. That is a consideration that seems not to have a definitive conclusion.........?

For me here I generally consider the wood to be dry at 10-12% and I get no mildew at this point.

.....Was just wondering what formula, thoughts on this by other turners might be. Do you hold off on roughing certain bowl blocks, and if you do, what is the reason? There may be more to the reasoning than mildew considerations. It's certain that the higher the MC, the more warp there will be (or, is possible)......but, the species and grain orientation aspects of certain specific examples of wood are a strong indicator of the amount of warp one will get, too..........

Thats a hard one Odie theres alot of variation in the wood responses to climate etc. For example I had the chance to pick up a good chunk of very dry of NZ wood when visiting there a few years back.It had sat on this turners wood rack for over ten years and was very light and dry.
Got back to Sydney Aust. never gave it a though chucked on the rack. A week later it had split wide open, just about ruined the blank completely.🙁

The type and origin of your blanks will have a great bearing how you will have to handle the blank. I have in the past had some blanks sent to me from Tasmania. Coated in wax and marked green, if I turn these on arrival I would need a rain coat. Tassy has a very wet climate heaps of rain and the wood has a very high water content and take 12months or more to dry out.

Cut, orientation, type etc are all further factors that need to be considered. A simple rule of thimb for me is to selectively scrape some of the wax coating of in a grid pattern then place several of the suspect blanks in a cardboard box. Together they will form ambient humidty of thier own in the box. The box in turn will slowly allow some moisture to be lost through cardboard.
I check them fairly often filling any cracks as they appear with CA. Cheap stuff you buy at the supermarket.
The real bad stuff I store away with all the wax on in the back of the garage and leave it, opening the box every few months or when I remember. Some I have are still in the box three years later. I slowly remove the wax coating as time goes by. How much and when 🙂 heck on this one I fly by the seat of my pants. Some I win, some I lose 🙂 mostly these days I win 80-90% trade the rest as pen blanks.