Gone to Pot

[Ginger Nut]

Well warming up here down under so shed time is on again.

1st job was some English Oak microwaved to dry it and turned up 2 Mortar & pestles one made from Stringy Bark the other unknown.

One on right LOML's the other gift for neighbour

Yes have metal projects on the go an adaptor for a chuck to fit the wood lathe.

[sparky961]

Microwaved?  Never heard of that one before.  What's the process?

[SwarfnStuff]

Hey Ginger,
     You got me a tad confused. You microwaved some English Oak but used Stringy Bark and some unknown wood, I assume the bowls are of the Stringy Bark and other. Are the Pestles made of the Oak? In the words of our red headed one time  politician, "Please Explain!" 
  Good looking job though.
John B

[Manxmodder]

Gingernut,please tell us more about the microwave drying technique.

I recall reading an article a few years ago in Eureka Engineering magazine where a Scandinavian company were using high frequency sound to drive moisture rapidly out through the end grain of large balks of timber....OZ.

[Ginger Nut]

  Sorry gents the Mortar are English Oak thats the bowls.

Yes the Oak was microwaved from a wringing wet to a 20% moisture Content chckd after about 5 days of air drying after the process.

NEVER use the indoors microwave to do this though toxic fumes linger

I/we have a large old microwave in the shed which is shared between Sue & myself as she uses it for dying.  NO not that sort of .........I mean to colour fibres such as sheep, alpaca dog see link. LOL's use of for dying http://woolnwood.blogspot.com.au/2011/12/adding-colour-to-life.html


I have taken photos of the process wrote it all up for those interested http://woolnwood.blogspot.com.au/2015/06/microwaving-english-oak-turning-blanks.html

The method I have used with the microwave I have is simple enough to follow. Remembering that microwave's heat from the inside out.
I have seen the results from a mate who stuck his camphor block in for 10mins on high approx same size as I was doing. It was charcoal inside almost ash.

Size matters!as does timber type, so does the time and temp setting as does the working range of the unit older units may only reach 750w while newer type reach 1400w to 2000w the bigger the power the quicker the timber can burn and even ignite.

I'll give an example of pen blank size 25x25x120 English oak which I also did of this lot.

There were some 20 pieces in all placed in an old large microwave, my turn table is stuffed (thats why SiL's mother was tossing it one day I'll look at why).
The temp setting is on high, time was 3mins BUT I open the door every 30sec to check progress and to turn them. Be carefull they do get hot and sap from various timbers weep out. The pen blanks took 6 mins in all for 20 pieces.

One of these solid blocks for the Mortar took 12mins total first session and a further 5mins day two, this was done thus. Timber was fresh cut 3 weeks prior and rain soaked as well. Mate who supplied had turn  piece wet reckons he should have worn a rain coat. I told him it was time he wore cloth when turning.
Single piece which was approx 6" dia by 7" tall
Again setting on high power, 3mins and opening the door every 60sec to turn/rotate (this if my turntable rotated I would not do, I would leave for 3mins then flip top bottom).
After 6mins I leave the door open for steam to clear and then start again this time I was having to wipe up moisture on the try.
I left it out over night to cool and then did a further 5 to 6 mins the next day sat it on the bench for a couple of weeks.
Both large pieces I did had some cracking but as i turned the inside rough and let dry for a few days these closed up tight through shrinkage (same as coopering).


 

[tom osselton]

Interesting thanks!