river oak bends ok.

[JDarvall]

sorry, its a bit of a, told you so post.

been told by many that it won't bend, so don't try it jake.

so, that meant I had to. :D

and it does. and bends very nicely too.

that 17x75x bout 900, bent into a 250 radius. good radius for chair back.

[conwood]

Hi Apricotripper
Pls tell us how. I have a job coming up requiring some bending.
cheers
conwood

[mic-d]

Another big steaming pile of success. Jake you're driving me around the bend :wink::D

tell us more please!
Love your chairs btw.

Cheers
Michael

[artme]

One for the filing system, but we need a lesson or three.

[JDarvall]

ta, I'm no teacher though. I only just got that bend now. And its bent in the regular way. nothing special.

just don't get why there's so much assertive advice saying it won't bend well, when it actually bent like butter.

[AlexS]

Probably from people like me he haven't tried it but just knew it wouldn't bend.
:D
Must say I'm surprised, though.

[JDarvall]

love the honesty Alex.:D

I'm a bit surprised too ....only cause you guys told me it wouldn't bend :rolleyes::D anyway.

.....

I did it around a tire hub I scrounged off a mates farm....you have to make up a bending strap, thats got end stops. long arms important for leaverage, here's a picture I take for my own reference.

what I found interesting is the radius of the bend is almost identical to that of an old chair I've got....and it seems to be a common radius in hubs (not that I know anything much about cars).......so I'm guessing that it was done this way much before, cause the hub being so strong its perfect for a former.

may help some... no matter what people tell you though, I can say with a fair bit of certainty......much patience is required with steam bending, talking weeks of experiments. There's no way really to know for certain whats going to happen unless you make a lot of kindling first.

[conwood]

Hi Apricotripper,
I understand the former you have made. Can you explain or show the steaming equipment. Did you steam a bit and form, then remove and re-steam and so on.

cheers
conwood

[JDarvall]

Hi Apricotripper,
I understand the former you have made. Can you explain or show the steaming equipment. Did you steam a bit and form, then remove and re-steam and so on.

cheers
conwood

probably best to find yourself some good reading on it from the net first, or buy a book. be better explained than myself.

basically, there's a box (homemade contraption out of ply, or pipe or whatever. that you feed with steam. you put all of the timber in there. leave it in there for certain time (dependent on thickness and timber type etc), pull it out, put it into a strap and bend it around the former in one shot as fast as you can.

off the top of my head some of things to consider.....

- is the grain straight enough...can get a good idea immediately by looking along the edge and seeing how the fibres run wrt the edge of the timber. ideally parallel. similar check as to when your hand planning. ideally split timbers best. but sometimes it doesn't have to be straight grained at all to bend ok.
- is the box getting enough heat.
- is the box getting enough water ? you want wet steam. lots of it.
- how long will this piece stay in the steamer for ? can go too long and too short.
- Is the strap strong enough to withstand the large pressures involved.
- am I organised enough to ensure the bend is done as quickly as possible before it cools. (found the heat gun handy here sometimes)

and then just keep experimenting taking a written log as you go, changing the system and processes slowly so you can pinpoint whats important as you break your timber.

its very frustrating at times.
good luck.

[Andy Mac]

Great result Jake! :2tsup: That timber will look sweet dressed up on one of your chairs. I had a look through your website... and your work is beautiful, no doubt about it.

Cheers

[JDarvall]

thanks mate.....btw, I use that bit you sent me everychair prittymuch. particularily handy in a couple of places. appreciate the effort.

[IanW]

......much patience is required with steam bending, talking weeks of experiments. There's no way really to know for certain whats going to happen unless you make a lot of kindling first.

Now THAT I can identify with, Jake. I've only done serious bending a couple of times, & each time produced enough fire-starters to last a season, before I got what I wanted!
'Tis a lot of fun if you have the time to persevere & get it right, though. (Trouble is, I do it so rarely I forget the lessons between times. :U)

Had I been asked, I would have said R.oak was unlikely to be a good bender, too, so am filing your info for possible future use - thanks. Did you use wood from a young tree, or an oldie (or don't know)? I ask because my own limited experience told me that wood from nice, straight, healthy saplings was a lot more likely to take heavy bending than wood from a mature tree.

Cheers,

[jmk89]

Also, I am assuming that the wood you used was still quite green, Jake. Is that correct?

[JDarvall]

. Did you use wood from a young tree, or an oldie (or don't know)? I ask because my own limited experience told me that wood from nice, straight, healthy saplings was a lot more likely to take heavy bending than wood from a mature tree.



yep, thats what they say, but I think the most significant things that lead to success ant based on that. I'm sure it helps, but it definetly not the most important thing imo.

I'll try and explain....

the river oak I got actually been sitting in a shed for 7 years. bone dry.

In my basic attempts to understand it earlier on I identified 3 kinds of growth. .....there the heartwood (dark red, hard as can be), then sort of a lighter brown colour.( dull greyish looking).....then a clearer sort of white toned stuff (which was clearly the sappest of the lot)

I figured the white toned stuff would bend the best, but it actually seemed more prone to compression failure. The heartwood and the greyish dull stuff bent the best. (though I felt the greyish was the best)....:? doesn't make sense according whats written a lot.

*****
but latter on it became clear what was most important. A few weeks ago I was bending a half dozern or so arms for highchairs. There tight 125mm radius bends.......idea was to bend as many at one time while the steamers running. 20minute intervals.

Doing too much as usual at one time, I didn't fill the kettles drip feed containers full in advance, and I fed the kettles too much to begin with.

So what happened was the kettles were bubbling away overflowing all the time.

The first 2 arms bent beautifully. But unknown to me at the time, the feed containers ran out and the kettles weren't overflowing anymore....still boiling away normally of coarse but weren't overflowing.

The next 2 bends failed dramitically. Both snapped like chalk at the first bit of pressure. :? confused. as one would expect a hard timber like river oak to behave I suppose.

nothing was different except when I looked in the kettles they only were about 1/3 full. I couldn't believe that could be the reason. such a dramatic difference in results just cause the water level was lower. But topped them up straight away.

and low and behold the next two arms bent beautifully.

Never really had this problem with any other timber. But it was great stuff up cause it revealed very clearly whats very important in bending it.

Wet steam. overflowing boiling kettles or whathaveyou. must have much water content in the chamber.

I feel the stuff must absorb moisture fast and become very pliable as a result .

but sometimes I'm certain if there's too much water in the chamber, with some timbers, it'll provoke compression failures as well.....

[IanW]

Hmmm, all very inetersting, Jake. Like you, I would have thought the sapwood would bend the best (the outer, sappier wood bent best in anything I've tried to date). And I'm surprised you got compression failure (i.e. on the INside of the bend) as I would expect tension failure in sapwood (i.e. parting & splitting on the OUTside), because it's already under tension, & bending it would apply even more, if it's toward the outside, as seems to be generally recommended. Of course, it seems you always use a strap, which is definitely the right thing to do, as it helps enormously to reduce tension failure.

However, I well know that things don't always follow the text books (or we haven't read far enough ahead to encounter all the 'ifs' 'buts' & 'ands'. :;), so all good info.....

I think you are right on the money that the wood needs to absorb a good deal of moisture if not wet. This is because plastic flow in wood requires molecules to slip past each other, which they can do much easier with bits of water between them (a very rough & approximate description, but it's been a very long time since Chemistry 101! :D). I've always found a good soaking before steaming doesn't do any harm at all...


Keep up the good work, Jake, you're re-learning lore that took generations to acquire & is largely lost to the majority of us. And keep telling us about your triumphs & tragedies - they can save some of us a lot of potential sweat! :U

Cheers,

[Woodwould]

I think you are right on the money that the wood needs to absorb a good deal of moisture if not wet. This is because plastic flow in wood requires molecules to slip past each other, which they can do much easier with bits of water between them (a very rough & approximate description, but it's been a very long time since Chemistry 101! :D). I've always found a good soaking before steaming doesn't do any harm at all...

In the pre- and industrialised periods of Windsor chair production, chair parts to be bent were usually boiled rather than steamed. I don't know when the practice of steaming chair parts came about.

For small-production or occasional use, a steamer is more convenient and requires far less fuel/power to operate. Full-time chair works would have had plenty of waste to fuel large tanks of boiling water.

[JDarvall]

Hmmm, all very inetersting, Jake. Like you, I would have thought the sapwood would bend the best (the outer, sappier wood bent best in anything I've tried to date). And I'm surprised you got compression failure (i.e. on the INside of the bend) as I would expect tension failure in sapwood (i.e. parting & splitting on the OUTside), because it's already under tension, & bending it would apply even more, if it's toward the outside, as seems to be generally recommended. Of course, it seems you always use a strap, which is definitely the right thing to do, as it helps enormously to reduce tension failure.

I've got a adjustable strap setup, whereby you can adjust its tension. Doesn't matter what the wood is you can tension it enough to avoid tension failure all together.

what happens with the sapier wood is its softer and tends to kink (compression failure) more. series of little kinks running around.



However, I well know that things don't always follow the text books (or we haven't read far enough ahead to encounter all the 'ifs' 'buts' & 'ands'. :;), so all good info.....

I think you are right on the money that the wood needs to absorb a good deal of moisture if not wet. This is because plastic flow in wood requires molecules to slip past each other, which they can do much easier with bits of water between them (a very rough & approximate description, but it's been a very long time since Chemistry 101! :D). I've always found a good soaking before steaming doesn't do any harm at all...


The books are good start, but won't get results alone, cause theres too many variables.



Keep up the good work, Jake, you're re-learning lore that took generations to acquire & is largely lost to the majority of us. And keep telling us about your triumphs & tragedies - they can save some of us a lot of potential sweat! :U

Cheers,

:)shore thing, expect 50 bucks from all of ya. should cover my time and loss of timber.

[JDarvall]

For small-production or occasional use, a steamer is more convenient and requires far less fuel/power to operate..

except the bloody power costs are going up 60% in my state. may have to switch to gas.

[Andy Mac]

thanks mate.....btw, I use that bit you sent me everychair prittymuch. particularily handy in a couple of places. appreciate the effort.

That is gratifying to hear, one that it works well, and two, that a handmade tool is being used on handmade furniture!:cool:



Keep up the good work, Jake, you're re-learning lore that took generations to acquire & is largely lost to the majority of us. And keep telling us about your triumphs & tragedies - they can save some of us a lot of potential sweat! :UCheers,

I agree, and along with Woodwould, we are extremely lucky to have such skills on open display.

Cheers,

[mic-d]

That is gratifying to hear, one that it works well, and two, that a handmade tool is being used on handmade furniture!

I agree, and along with Woodwould, we are extremely lucky to have such skills on open display.

Cheers,

Hear Hear!! (on both counts)

Cheers
Michael

[JDarvall]

ta. but you'll give me a big head with stuff like that.

[IanW]

ta. but you'll give me a big head with stuff like that.

Don't you worry about that, Jake!
We'll soon let you know if we think your hat's looking a bit small.....
:U :U