"Prometheus" wrote in message
...
Hello all,
I decided to try out the LDD method, and while the jury's still out on
the final result, I did a little research to try and figure out just
how and why it might work.
A quick Google search turned up several high school science
experiments that used LDD in a 20:1 to 10:1 (Water:LDD) solution to
break the cell membranes of both human cheek cells and onion cells.
PBS's NOVA referred to this as "lysing" in their explaination of the
experiment. The broken cells released their contents into the solution
so that the DNA could be extracted and spooled for genetic typing.
Further searching showed that there is a single chemical that can be
used for the same purpose, which I would expect is one of the
ingredients of LDD-
Sodium Laurylsulfate
( C12H25NaO4S )
AKA: n-Dodecylsulfate Sodium Salt
CAS no: 151-21-3
Since the experiment in question worked with both onions and cheek
cells, it is fairly likely that this salt is able to break open not
only animal cells with a fatty membrane, but the sturdier plant cell
walls as well. Once the walls are split, the contents are released
and the water can be pulled out of the wood (somehow, that's how- I'm
a steelworker, not a chemist!)
Like I said above, I tried the LDD method, but I really did not enjoy
the sloppy slurry that came off the piece for the first several cuts.
I'm going to blame that on the glycerine in the soap, just for the
heck of it. If this is the chemical that does the job of preventing
wet wood from cracking, it may be a good deal cleaner and less
expensive than buying large containers of dishwashing detergent. If
anyone feels inclined to experiment with it a bit, there are a few
questions that obviously need to be answered.
First, does it work at all with the Sodium Laurylsulfate, and if so,
at what solution? It's a safe bet that if this is indeed an
ingredient in LDD (I couldn't find an ingredient list on the bottle)
it is severely diluted in the final solution, so a lot less than a
50/50 mixture should be needed. The DNA experiements called for a 10%
solution when using the chemical above.
Second, If the method does work- how does splitting the cell walls
throughout the wood affect the finished product? While it may prevent
cracking, It seems rather unlikely that it can eliminate shrinking and
warping. It may just be a nice fast way to dry out wet wood- or it
may cause cells to retain their shape because the water is able to
leave the cell through a crack, rather than collapsing due to the loss
of turgor pressure.
Third, how is water pulled out of the cells and into the solution? In
the experiments, a bit of salt was added to the mixture (1 teaspoon
salt to 1 cup of water, and 20 drops of the 10% Sodium Laurylsulfate
solution), but I'm not entirely sure if making the solution salty
would dessicate the wood. I know that salt can trap water, but if
it's already dissolved in the water, who's to say it isn't already
loaded with all the water it can handle?
Fourth, does a guy need to wear gloves when handling the piece to
prevent some nasty dermatitis? It's also a good bet that LDD contains
moisturizers to protect your hands.
Fifth, how does a solution like this affect various finishes- or does
it not affect them at all?
And Sixth, is it possible to buy this chemical without a special
license?
Of course, all of this may be just a bunch of hoodoo, but if there is
something actually going on, it may be very useful to all the turners
here if the chemical reactions can be isolated, explained and
replicated. If any of you are interested in biological chemistry and
can figure this out, let the rest of us know- or maybe whip up a bunch
and sell it on your website or something. I'll probably mess with it
a bit, but I've got too many other things to do, and not enough time
to do them all!
Anyhow, thought I'd share.
Prometheus: A noble and worthwhile thought and sharing, but be prepared to
suffer the fate of your namesake. The LDD topic arouses all sorts of
reactions from turners. We have speculated on this before and you bring up
some interesting points, but "we" decided that it would take a scientific
investigation into the actual effects of LDD on wood. The cost is
prohibitive. Perhaps some scientist can obtain a grant from the National
Endowment for the Arts to pursue this. After all, if they can support
artists who produce such things as "**** Jesus," a few million for a study
that might produce evidence of global warming in an LDD solution should be a
snap!.
In the meantime, take good care of your liver! *G*
Leif
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