Bending with un-seasoned wood ? or maybe not?

I've been looking at this site...they are bending wood with high moisture content for better results.
http://ercolblog.com/manufacturing/the-art-of-steam-bending/

You can't fool me Ken - you want those hydraulic machines, and you want them baaaad...

Actually no..it's not about wanting machines "this time" (but I do love machines, want want want!)....it's just that i'm confused with the idea that ..You stack wood away for years in a sheltered place to dry out...and then!!!! when you need to bend it into a particular shape?? the first thing you do is introduce it to water again, before heat treatment and bending...Why not go for it as soon as the tree is felled ??

Did a "Wet wood weekend" when I was at college a long time ago, chairmaking with green timber that we felled ourselves (Oak, Ash and Sycamore). Green timber is almost a different material than seasoned stuff, really plastic. Thonet bentwood chairs were made out of green timber, I believe. It works beautifully with edge tools, drawknives, adzes etc but the challenge would be getting it to a uniform thickness. Then again the Shakers made hat boxes like that so it must be doable.

I suppose if they bake the wood down to 6 or 7 % moisture content the wood would be stable and not move anymore. But I wouldn't bet on it. Pretty cool watching them bending those chair parts!

They don't call it 'green' for no reason... it's a mtaphor for 'not ready yet'.

I work with green and kiln dried. Green is nice. It resaws much easier, but it needs to be dried after that. A few days in the air path of a fan usually brings the moisture between 8-12%, depending on the ambient RH in the shop. On the other hand, kiln dried or well seasoned lumber has had enough time to get most of it's movement done. One advantage to drying down to 6-8% is that the wood won't shrink anymore than it already has, under natural environmental conditions. Air drying will usually only bring it down to 10-12% in 1' stock, but it takes so darn long, the wood naturally stabilizes the tension. The danger primarily lies in post assembly shrinking. When the wood shrinks back, you get cracks. Expansion is usually not a problem.

Having said that, I haven't noticed any drawbacks with resawing green, then stickering and air drying to 10-12%. A number of our instruments are shipped directly to Japan, where the fall and winter are very cold and dry. So far, we haven't had an increase on weather related repairs since working with green.

Just don't be tempted to resaw too green or you'll wind up with a stack of potato chips after it's dried. I find it easiest on the saw to resaw when the wood is down to about 15% and that seems to be dry enough to avoid any major warping. I then further dry it in a dehumidified environment until it's down to 6% to 8%.
With wood it's best to plan ahead. I'm air drying so green wood I'm buying today won't be used for five years. I don't like to force the drying. Generally, the longer the better.

I didn't watch the vid, but from a furniture making perspective, if green is available for steam bending, that's what I use. I have only played with hot-pipe bending once, but I would guess that the result is similar, particularly at the thicknesses used in luthery.

I too would be wary of doing thin resawing of green-wood. I've done it a couple times with "half dry" wood, and it seems to be a form of russian roulette. All timber cutting is resawing, so the reality is that you can resaw as far as you like if you're willing to waste when it comes time to mill to spec.

Regarding milling green lumber, a sharp blade really helps. I know it sounds elementary, but a lot of people use their blades until it won't cut a hot dog. I keep mine razor sharp and resharpen or change out at the first sign of dulling. The amount of moisture usually isn't a problem, more how well it's distributed throughout the board. I've cut through spitting water at me green to 6% dry and the worst pieces are the ones that aren't evenly dry or wet. We had a lot of problems with case hardening in the past, so we built a kiln and it's been a lot better since. If I do need to pull a load prematurely, at least I know what I'm dealing with. The only thing I don't like about cutting green is stickering with chopsticks and rubber bands. Then again, it's not my job, so I can't really complain first hand.

You're right about potato chips Chuck. I bought some lovely koa unseen on ebay about 5 years ago and my man in California converted it for me without discussing it being green. The stuff is great but it did twist and warp and dried down to almost thickness - good job the saw used produced a finish akin to 60 grit.... However, when it is passed through the sander and is cut to profile it is fine.

koalohapaul said:

Regarding milling green lumber, a sharp blade really helps. I know it sounds elementary, but a lot of people use their blades until it won't cut a hot dog. I keep mine razor sharp and resharpen or change out at the first sign of dulling. The amount of moisture usually isn't a problem, more how well it's distributed throughout the board. I've cut through spitting water at me green to 6% dry and the worst pieces are the ones that aren't evenly dry or wet. We had a lot of problems with case hardening in the past, so we built a kiln and it's been a lot better since. If I do need to pull a load prematurely, at least I know what I'm dealing with. The only thing I don't like about cutting green is stickering with chopsticks and rubber bands. Then again, it's not my job, so I can't really complain first hand.

Click to expand...

yup, thats usually my job...