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.