Working wet wood, how do you do it?

[Honest John]

I generally buy my timber dry and reasonably stable. I also occasionally come across logs harvested from trees that have come down and it’s a buz to create something from a lump of tree rather than a dry and prepared blank. However, I have rather mixed results with regard to part turning and drying. I have just lost one bowl before I could even take it off the lathe. I reduced the wall thickness to about 10% of the diameter and then watched in horror as a crack opened from the rim and proceeded halfway down the side to about 2.5mm wide. My intention was to rough turn to 10% soak it with lemon oil! Rap bag and leave for a while and monitor. I never got that far. I have had success with this method but not as consistently as I would like. Yesterday evening I was browsing YouTube and found a post from a Turner whom was building a “drying cabinet”. This was fashioned from a cardboard box, a small computer fan and a light bulb. His intention was to rough turn to 10% then pack in this box for several days before completing the turning! This kind of goes against what I have always understood to be best practice, that is dry slowly in a draft free place, and here is this guy creating heat and draft to dry it quickly ? I’ve had better success with thin walled tuned to completion items, but this is not always what is wanted.
My bowl with the big crack in it did not contain the pith, but did have some very uneven grain patterns due to other limbs in the near vicinity. Perhaps it was doomed to failure because of this? How do you guys work your wet wood?

 

[Dalboy]

A lot can also be down to the type of wood as there are some that will crack very readily. I normally turn down to an even 1" thickness and seal the outside only and then stack in stick not had any failures yet touch wood, you watch the next one will crack now I have said that

 

[Robbo3]

The general idea is to remove the bulk of the wood & the moisture that's combined within it, which also relieves some of the inherent stresses, then leave to dry. With the stresses relieved, hopefully the work will only warp & not crack.
Two bits of wood from the same branch can often react differently, with one cracking & one not.
Drying cabinets (kilns) using old fridges, freezers or home made have been around for a long time. Although speeding up the drying, it is more about controlling the process rather than leaving it to chance.

 

[SVB]

There can be loads of factors at play here.

An important one is with the timber itself. Was the piece you were working from an even trunk or was the tree growing on slope or even were you using branch wood?

As has been said, it is all about letting the stress within the timber release whilst the timber drys and the fibres shrink as they loose the water. If you piece has high internal stress anyway due to how the tree had grown that can contribute significantly to the success rate.

S

 

[finneyb]

That's not a crack - its a design opportunity.
Seen them filled with all kinds of contrasting material
Even laced as in a shoelace.
Or even cut the sides of the crack back into a curve so that the bowl has a partially open side.
Or hold the crack with dovetails/butterflies again as a feature.

Move away from brown and round and let the wood dictate.

Take care when turning with the crack - slower speed and duct tape around the bowl when you can.

Brian

 

[finneyb]

An example of dealing with a crack https://www.youtube.com/watch?v=4_kKUBHd4hM

Brian

 

[Honest John]

lifes too short to figure out the quotation facility so
Finneyb : I’ve seen the Alan Stratton video and what he did in that one is not far away from what I’m thinking may become of this latest cracked bowl eventually. I have in the past filled cracks and blemishes with various metal powders, epoxy resins and also milliput epoxy putty to good effect. I think this particular blank was doomed to failure from the start. It was cut brom the base section of a cherry tree that came down in recent storms. It was very irregular and shrinkage was always going to be an issue, I just didn’t expect it to happen whilst I was turning it. Clearly I had released some tensions in the wood. I have some other sections of the same tree that I have cut down the pith into half logs and sealed the ends. These are much more regular and should yield 2 or 3 bowl blanks from each half section. I have much higher hopes for these sections. The reason for my original post that this guy on you tube was blowing air over his blanks to dry them in a few days and my understanding was that 5his process was to proceed much slower than this and in a draft free environment.
Dalboy. I’m super impressed that you have had so few failures with your part turning and drying, and I shall strive to emulate your process. How long are you talking in stick? My cherry logs are very wet, I think I measured about 22% wme
With my protimeter, so there’s a lot of water to remove. I took the bowl blank down to about 24mm wall thickness and was just about to finish when the crack opened up (hammer)