Messing around with the LDD method

individual,

Perhaps not, but I suppose it depends on what he was wanting to measure. It seems simple enough to try different chemicals, turn a bowl, and see if it cracks. Dan

hey, one man's fetish is another's hobby, right? it's why there are groups like this, because folks take interest in things... (after oval, try something challenging like a hex turning lathe.. *g*

mac

Please remove splinters before emailing

=====>Gosh, Rob! Does that mean you don't watch the LDDs, errh, I mean the "soaps?" *G*

Leif

Mac, If I change the gearing it could! And turn tri-cornered and quad-cornered, and... :) Dan

======================== Dan, You don't even have to change gears to do tri and quad figures, just offset centers and you have it.

Ken Moon Webberville, TX.

Well, that's enough for some, but hardly scientific. We have those folks who say soaking in detergent keeps a bowl from cracking while neglected for a day. Or, if you turn thin and soak, it won't crack. It makes it easier to sand and keeps the dust down....

Of course soaking in anything miscible with water will keep the piece from losing moisture, almost any piece turned to less than 1/2" has to be abused to crack while drying, and any sanding lube (I can say that now that Andy's gone, can't I?) will make sweeping compound rather than clouds of dust when sanding.

It's not whether you succeed with a bowl, but whether that success was due to the chemistry or in the natural scheme of things. In experiments, it's called a control.

Thus the constant reminders to study how wood dries before you assume, then cap your assumptions with halos.

Gotcha. Like I said above, it was just thinking aloud- I know my limitations when it comes to chemistry!

Something like this would do the trick, though I have no idea who makes the best one for the job.

Takes all kinds, doesn't it! Dan>

>

Sorta. On my machine the workpiece is constantly offsetting, making a smooth transition from the curved side to a curved corner. Just as there is a difference between offset turning and oval/elliptical turning. Offset turning leaves you with and edge where the two arcs intersect.

Dan

Well, its certainly more that not doing anything, which is what I'm hearing from the group.

You make good points, and they are quite true, and setting up all these hurdles to jump is more discouraging than encouraging, to me. Your point seems to be "we can't do anything unless we have a grant, fancy equipment, and set up a random control trial."

Which is a load of cr*p when you consider how many scientific advances have occurred in garages. Besides, before you can start an experiment you need a hypothesis and we don't have enough observable data to warrant creating a hypothesis yet. That is the role of testing, to see if an observable effect exists.

What I'm saying is that we don't know much about LDD, but we'd know a lot more with just a little empirical testing. No reason to get NASA, Bell Labs, or Sandia involved in this project, unless of course you are a beltway bandit and hoping to score a grant?

Dan

NEA probably would not- but a R&D dept for a large sawmill (if any of them have such a beast these days) might be interested in a new way to stabilize wood. Especially if it managed to decrease the amount of shrinkage- imagine all the essentially "free" wood they'd have if a piece of timber could be cut to finished size and they didn't have to account for shrinkage. Could save space when storing if the lumber didn't have to be stickered as well. Space is always at a premium anywhere!

Thanks! Actually, I have more time than cash invested. I probably have less invested than a new One-Way lathe costs. A lot of the parts were scavenged, bartered, or won on eBay.

The Thompson slides 'could' be fitted with servo motors, and I know that there are little PC solutions for running XY tables, but I'd rather not. Even though turning a crank isn't the same enjoyment as gripping a gouge, I've been doing that for years on my metal lathe and mill. And I don't have servos on them, either.

However, it would be a great solution if I needed mass quantities of the same shape for some reason.

Dan

Prometheus, Great thread you started! I contacted the Forest Product Labs and asked them about LDD and gave them all the technical information you and everyone else has provided with the hopes that someone there, or in some university somewhere, this had been investigated. Here is there reply:

"Dear Mr. Bollinger, Thank you for your email inquiry! We do not have any information on this method of stabilizing wood. We do have a packet of information that uses PEG (polyethylene glycol) ---this method can be found in our Wood Handbook, Wood as an Engineering Material

"Not what I hoped for. Dan

Dan Bollinger wrote: snip

snip

The reason that you're not hearing anything from the group is evident if you do a google on this. Most who have been here more than a couple of years have been down this road so many times that we can find our way in the dark. Nothing conclusive has been found other than the soap:water ratio becomes critical below a certain level. It gets numbing after a time. By all means, go ahead and run the tests, make your own concusions and let us know what you come up with.

Dave in Fairfax

Something I heard on the radio about AA seems like it would fit in here- "Sometimes the best is the enemy of the good" While it sure would be nifty to figure out exactly what is occuring by watching things happen under an electron microscope or some other spiffy toy, that shouldn't stop a guy from playing with different formulas and taking notes on the result.

As far I understand it, all you should need for an experiment is a couple of test batches, a control group, and some reasonable means of measuring your results. To make it a valid experiment, a person needs to take notes on the processes, and then have someone else (preferably many other people) run the same processes, and determine whether or not the results are repeatable.

Now, that doesn't get down to a molecular level, and it won't tell you everything about what is going on- actually, it may tell you very little about the reaction itself, but it should work okay for isolating the active ingredients and determining what concentration for them is needed.

For Mac- the reason it's useful to figure some of these things out is so that a guy can make sure it works every time- rather than having a nice piece of work split on you because you used Ivory dish soap rather than Dawn. It lends the method credibility, and leads to a much better experience for those that would prefer to simply use it and not ask why. That doesn't mean *you* have to do it, but it may mean that someone else does and can pass a recipe along. I know I'd much rather keep a kilogram of power in my shop that I can mix with water when it's needed than a giant box of bottles of dish soap! That, and always asking why keeps a guy sharp.

We got to where we are today because a bunch of people grasping in the dark figured out a way to systematically ask questions. They didn't just invent fancy machines- first they had to figure out just what it was they needed those machines for, and the machines followed of necessity. When you look at the final results, it seems insanely complex, but every complex system is only an set of simple concepts and parts. When I look at a piece of complex machinery, it at first seems like something that is far beyond the reach of most people to understand- it's just too convoluted. But further inspection shows that it's just made of simple machines joined together. I can understand a lever, I can understand a screw- a wheel and axle or an inclined plane are not too tough either. It's not too much of a stretch to figure out how a lever can be used to turn a wheel with a bit of string around the axle, or how that wheel might turn a screw. It's *all* simple stuff, just put together in creative ways by someone who cared.

For what it's worth, anyhow.

Dave, I don't need to Google anything. I've been a member of RCT for many years and recall the conversations. But even if I did, all I'd find is more evidence that this potentially valuable technique hasn't improved or been understood in those years. Which is a shame since the size of wood blocks we need for turning bowls cannot be dried in kilns, and even if they could, we might not be able to afford them. The reason nothing conclusive has been found is because no one is looking!!! I don't use LDD. I don't need to run the tests for me. But I can tell you there are many people here who wish someone would! I am encouraging people in the group to invest a little time in understanding this more.

Dan

My apology, I didn't mean to offend you. I didn't check to see how long you'd been posting, much less wonder how long you'd been lurking. It seems to me that a while back Andi Wolfe and someone else, whose name I should remember, but don't, did look at this in a fairly scientific method (pun intended) and either didn't come up with a good conclusion or else gave up after realizing the amount of work necessary to really run down the answer.

I was serious about you doing the legwork if you wanted to, and getting back to us about it. It would be nice to know once and for all what the mechanism is, and whether there are any grounds to the LDD. OTOH, it won't affect the bucket of the stuff I've been using for several years now. %-) Ya gotta have faith in SOMETHING.

Dave in Fairfax

I'll test the prototype, Dan.. got a kevlar turning suit handy?

mac

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Science is great, but not holy. I'm with Dave. I gave up and washed my hands of that soapy LDD science, except for joshing Leif, long ago. I'll sit by and await the results of those with a more inquiring mind and the time to use or waste it. A chance observation isn't a scientific experiment in which a theory is already held (sometimes too tightly) in mind.

I think it's ok to use LDD or not to use it in whatever uncontrolled methods we slobs (not you, Dave) mess around with. We feel no guilt for not glimpsing the larger picture and take no blame for the descent of man. :) Empirically, Arch

*********************************************** p.s. I'm just kidding around in ignorance, but I have read some of the ideas of Thomas Kuhn and others about the history and current concepts of what science really is and scientists really are. For me, they are a comfortable rebuttal to those who don't count medicine or social work ..or woodturning as science. A.