Prior to November of 2001, a premier bowl turner from Canada had a loss rate as high as 25%
when turning burls and water recovered hardwood into bowls.
Don Thur of Knots & Burls to Bowls had experimented with a number of methods from
Anchorseal, paint, and WD-40 to keep his green wood from cracking, splitting and distortion
with minimal success, losing upwards of 25% of his turnings and taking up to 3 or 4 months to
In November of 2001, Mr. Thur began using Pentacryl exclusively to treat all of his green wood.
Since making the switch, he has lost less than 1% of the 382 pieces he has turned. These bowls
range in sizes from 6” in diameter by 1” high up to 30” in diameter by 8” high.
In addition to the dramatic reduction in losses due to cracking, splitting, and distortion, the
drying time has also been dramatically reduced as well. An average drying time for a 16”
green-turned bowl has been reduced to 4 or 5 weeks, down from 3 or 4 months; a 3 fold time
Knots & Burls to Bowls has calculated that it takes approximately 4.11 fluid ounces of Pentacryl
at a cost of CDN $1.44 to treat an average piece.
Mr. Thur’s treatment method is to rough-out the bowl and then soak the entire piece in a
container of Pentacryl for about 2 days. He then allows the piece to drip-dry before placing it
in a completely enclosed shed with minimal air movement. While the piece is in this area, it is
placed upside down on slats to insure that moisture is not leaving the inside of the piece other
than at a very slow rate of evaporation.
When the moisture content reaches 25% +/-, the roughed-out bowl is then placed into a 6′ x
12′, well insulated drying shed, again on a rack, this time right-side up. Here the temperature
is kept at 70° Fahrenheit, supplied by a $99.00 passive electric heater from Home Depot, until
the moisture content reaches 10% at which time it will be finish-turned. The complete process
is in the range of 5-6 weeks from rough-out to gallery shelf.
Knots & Burls to Bowls has been turning bowls since 1995. They have created pieces for the
King and Queen of Norway, the Lt-Governor of Ontario, Canada, the District of Muskoka,
Ontario, Canada as well as dignitaries from other countries including England.