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Thread: Steam bending chair parts - Peter Galberts Modern Windsor Rocker

  1. #1
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    Steam bending chair parts - Peter Galberts Modern Windsor Rocker

    I purchased plans from FWW (SU24) for this chair.

    It's my first attempt at steam bending parts. From what I read, it's important to strap clamp the ends to avoid stretching/breaking on the outside curve. However, Galbert's plans do not call for that. The bends are relatively small, and the spindles are only 5/8", so I can understand that. However, the back posts are 1 1/2" thick.

    What's your general rule of thumb for this kind of thing?

  2. #2
    I bend 3/4" cherry and walnut for music stand legs. With a metal strap I get about 10% failure.Without it is closer to 50%.

  3. #3
    An old shop mate of mine makes these from steam bent walnut. I think the thick parts are actually made by bending 2" square lumber. This allows for machining back to 1.5". She only uses air dried lumber and is very particular about grain, no cross grain at all. She preloads her strapping before bending. All bent peices are then dried clamped into cauls. And, yes, failure rates were high.
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  4. #4
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    Prashun, if your working from riven parts then a failure will be fairly rare. If your careful you can get nearly the same quality from rift stock straight grained (vg). Quarter sawn usually runs out on the flat sawn face and so it can break easier than rift vg.
    Bumbling forward into the unknown.

  5. #5
    About 40% of the battle is getting the right wood.
    About 30% is getting it hot and wet enough.
    The last 30% is technique and practice.

    First - safety wise.... You will be dealing with boiling hot wood that comes out of a huge boiling pot or hot steam box. You can get burned really bad if you don't have the right Protective gear... Thick, long, waterproof, hot gloves are a must. I might also want a rain coat and rain pants to keep boiling water off my skin....

    Wood wise: straight grain with minimum runout is going to be the recipe. No knots, no twist, no crossgrain. Quartersawn, clear, straight grain.. Air dried...

    Next is type of wood. Oak and ash are #1 unless you can get willow. Willow is absolutely magic for bending.. Get it wet and hot and it will about flop onto your form. Cherry, maple, hickory, and walnut are next. True rosewoods also bend quite easily... Mahogany of all woods can be the absolute crankiest stuff to hot bend - and it's unpredictable. One piece of mahogany bends perfectly and the next breaks your jig then snaps in half.. Soft woods like pine, spruce, and cedar are nearly impossible to hot bend...

    This will sound crazy and like way too much work... But if you have a plenty of time and a good looking log (no twist or knots)... Hand split the log into cants and then resaw boards off the cants following the grain.... Let it air dry about 6 months and go at it...

    Next step is hot and wet enough. The classic technique is to boil the wood for a couple hours and then clamp it to a jig while boiling hot... You can also use a steam box to heat it to boiling hot... The top metal strap helps to keep the grain from letting go on the top. The classic thing was to use thin spring steel slats - but it stains wood pretty bad. 0.020" thick Stainless steel shim stock works well... Just cut a few holes on the end to strap it to your frame.

    Work out your jigs ahead of time. Once you pull the wood out of the wood soup - you have to work fast. Have a friend there... All your clamps ready.. All your straps ready... You will feel the wood is pliable - work fast and efficiently. If you mess up - stop. Don't try to force it when it stiffens up or it will break.... You will have to re-heat it and go some more...
    Last edited by John C Cox; 03-15-2018 at 9:31 PM.

  6. #6
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    Very helpful responses, guys. Thank you.

    I have purchased some riven stock from Elia Bizarri. I am also practicing at harvesting my own. The last Nor Easter left some reasonable logs all around. Splitting is not as easy as Curtis Buchanan would have me believe

    We have an abundance of red oak around me.

  7. #7
    Lol.. Yes about splitting..... The #1 thing for me was to have a LOT of good wedges. Probably 6-8 decent steel ones and a dozen wooden ones... And a good sledge hammer.. You never have enough wedges.

    The trick here is also to not try to force the log to split.. Just kinda work the crack open and off it goes... Slip in another wedge and work down the log...

    Don't get greedy trying to split the whole tree or to think you can work with knots/twist/defects.... If you need 3' pieces - cut a 3'6 or 4' log section that looks perfect and give it a go.. There is a gigantic amount of waste doing this - which is a big reason it isn't done much and the wood is expensive... You may only get a 3' length good and clear out of an entire 10' log...

    After your first log - you will realize really quick that it isn't worth even fooling with trying to sneak a section off the back side of a log with obvious defects all over the place...

    On the jigs - you will often notice that many of the jigs you see capture the wood on one end and you pull it down from the other end... Make sure you have some big long reach clamps, or even a car jack you can use to pull the end down quick.

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