Hi Kevin
Drying bowls how, you ask???
There are some basics, but there are many BUTs, and IT DEPENDS, so what
works for me should also work for you, yes, IF your conditions are like
mine, your wood the same, thickness etc etc etc.
Give up yet ??
So what do I do.
Normally turn to 8-10% at the rim, than thinner as I go to the bottom.
Make sure I start with wood that does not have splits already, it I
don't want splits in my finished work
I date and I.D. the rough out, and go over the turning very carefully
to see if there are any signs of checking, ( if there is any, it is
almost always because they were there already, and normally get caught
while turning the outside, and I turn them away) also are there knots
or the rim very close to the pith, knots are CA'd with thin CA soaking
in, the pith area gets CA often if I expect the wood to check.
Some woods I will paper bag, or newspaper if to big for a bag, which
wood you ask, well in my case not many but Cherry and Mulberry are
often bagged, and also the ones with the very small checks, and I do
not CA the small checks, I used to do that, but the glue lines will
stay, and now I will just let the roughout dry, I do check them
regularly in the beginning less so after the initial week or so.
I found that often the small hairline cracks are totally gone when the
wood has dried, if not and I am not able to turn them away, then I
might soak in 50/50 glue /water for a few hours and give them another
drying tour, the water/glue soak will swell the wood and the glue will
keep the wood from opening up again, works for me and you won't see the
glue lines like the CA lines in my experience.
I do anchor seal bowl blanks, but not roughouts.
Now my cabin that I build to dry my roughouts is almost airtight and
fully insulated, the seams were caulked and the small windows double
paned with lexan, the interior walls floor and ceiling and doors are
unpainted wood, (1 infrared 150 watt light bulb will keep the interior
above freezing if I find the humidity going to high) the reasoning for
this is that the wood from the building and the roughouts and also the
air work like a absorber, slowing down the humidity swings and also the
insulation slows down the temperature swings, it still gets hot or cold
but it takes longer, the humidity will get higher or lower but it takes
longer, the wood will dry but it takes longer.
I have used this for well over 10 years now and it works for me.
I did get unexpected splitting but they are very few and far between, 1
or 2 cases I got by leaving the doors open one sunny day and a big Elm
that was in there for only a few weeks got a large split, and also one
day I had a larger black walnut sitting on my mower where the sun shone
onto it, I got checks on the inside and outside where the sun shone in
and against it, so yes I do screw up sometimes, but other than that
hardly any unexpected splitting.
Then there are those times when I turn something with a large knot or
reaction wood and/or bark inclusions, I do know that some might split
on me, for instance I do have one black walnut crotch wood turning
right now that has some bark inclusions and also a knot inline with
that, bark and natural edge also left on it, I did know that it was
going to split on me so I made a stainless steel staple from wire and
put that across the bark inclusion, yes the knot split but the bowl is
still together, BUT SOMETIMES YOU CAN"T WIN.
The best way to keep wood from splitting is to give it time, give it
time to move while the water leaves the wood, give it time to keep the
stresses low in the wood while drying.
If there is TOO much of a difference between the amount of water on the
edge of the wood and deeper inside the wood than the wood WILL split,
however some wood splits not as quickly as other wood Elm, Catalpa,
Willow etc. are some woods that I know not to split easily, Arbutes,
Lilac, Tartarian Honey Suckle are some that I know want to split just
looking at it.
Boiling these does help, in my experience, (boil 1 hour per inch of
thickness and keep and leave under the water till it has cooled off)
Well this should cover most of your question I hope.
http://homepage.mac.com/l.vanderloo/PhotoAlbum4.html
Have fun and take care
Leo Van Der Loo
Kevin Miller wrote:
Inspired by Leo V's website, I've spent the last couple of days doing
roughing mostly. Still have a long way to go before I match Leo's three
zillion blanks drying on the shelf, but it's a start.
Got me thinking about drying though. Usually I rough turn to 10% of
diameter, slather on end grain sealer inside and out (on the end grain -
I ignore the side grain) then toss them in a paper bag w/shavings.
Wondering what everybody else does. Leo seems to coat them and toss
them on the shelf w/o any bagging. I presume he coats the inside and
out. Is the whole thing coated?
So what's everybody else do after roughing? Seal and bag? Seal only?
Seal inside and out? Various permutations of the above? Yeah, I know
about finish turning wet bowls and letting them warp. But I'm not
asking about that.
S'later...
...Kevin
--
Kevin Miller
http://www.alaska.net/~atftb
Juneau, Alaska
Registered Linux User No: 307357