hawkeyefxr
Established Member
Has anyone used a mocrowave for drying wood ready for turning.
drying wood
- Thread starter hawkeyefxr
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red dave
Established Member
I have done this on 3" timber but only for short bursts as you could set the wood on fire.put it in thenhawkeyefxr":2tajts5s said:
let it cool down before repeating.then let it cool and then put it somewhere warm.please be carefull.
Honest John
Established Member
Hawkeyefxr, my experience of this is very mixed, and I suspect that that may always be the case. Some great successses and some dire failures. The method I used was to weigh the wood then nuke it on a medium setting for about a minute or maybe a minute and a half. I then removed the wood and wrapped it in kitchen towels to absorb the moisture and leave to cool. It never seemed a good plan to me to get the wood very hot. Warm to the hand but not hot seemed about right. When it's cooled, and dry on the outside, weigh it again and record this weight. This process I repeat many times over a few days. When the weight stops reducing each time your wood should be dry.
Enormous changes must take place when wood dries, and rushing a normally slow process I'm sure can have some consequences. Removing the "easy water" will be quick, but encouraging the individual plant cells that have aqueous solutions within their cell walls to give it up is a different matter altogether. Some pieces I treated which from memory was sycamore, looked good and without damage at the end of the process, cracked and split spectacularly after a few months. I can only imagine that there were some serious stresses released that took some time to achieve its resolution. These pieces were dry ! Other occasions turnings have responded well with no problems. One thing I did discover was that wall thickness had to be a constant thickness. The base of vessels if left a little thicker as is often done normally could be a source of problems. Good luck with your efforts.
Enormous changes must take place when wood dries, and rushing a normally slow process I'm sure can have some consequences. Removing the "easy water" will be quick, but encouraging the individual plant cells that have aqueous solutions within their cell walls to give it up is a different matter altogether. Some pieces I treated which from memory was sycamore, looked good and without damage at the end of the process, cracked and split spectacularly after a few months. I can only imagine that there were some serious stresses released that took some time to achieve its resolution. These pieces were dry ! Other occasions turnings have responded well with no problems. One thing I did discover was that wall thickness had to be a constant thickness. The base of vessels if left a little thicker as is often done normally could be a source of problems. Good luck with your efforts.
hawkeyefxr
Established Member
Well before i saw these replies i had a go. My piece of wood was make a bowl about 5in dia x 2 /1/2 deep.
What amazed me was how much water was removed !!, from my small piece of wood i got 169g of water!!.
The downside was they the wood tore internally because i did it to fast, 1min on half power but did 25 of these with only a small break in between.
The paper towel bit is a good idea, i will try this nest time, and take more time to stop the wood overheating.
What amazed me was how much water was removed !!, from my small piece of wood i got 169g of water!!.
The downside was they the wood tore internally because i did it to fast, 1min on half power but did 25 of these with only a small break in between.
The paper towel bit is a good idea, i will try this nest time, and take more time to stop the wood overheating.
Honest John
Established Member
Sorry i misread your original post. I didn't realise that you were drying wood prior to turning. I've only ever done it the other way round. Turning wet wood can be a lot of fun, and removes both wood and water from the blank, leaving a lot less to dry. Many turners use only wet wood as it is often available cheap or free, and can offer some unique opportunities. Maintaining a constant wall thickness is key to the success. Although I've no experience of drying wood in a microwave before it is turned, I would imagine that it would likely be more problematic than turning it before it is dried. A three percent shrinkage across a thin wall may not be noticeable or troublesome, but the same percentage shrinkage across a 75mm thick piece of wood will almost certainly give a serious problem. Incidentally, very thin walled turnings when nuked to a good warm temperature can become very plastic and be bent and molded into bizarre shapes that set hard when they cool. Not everyone's cup of tea, but interesting non the less.
