First steam bending

[David Rose]

I finally got a day when I didn't have the flu, it wasn't too windy or too cold and the light was still shining to give this a try.

The apparatus is really simple. Just a gas can, turkey frier burner, and a long box of 2x6s. The pic doesn't show the doors to the box. They are just blocks with a gate hinge on the top. I threw the rags over the doors which leak a lot on purpose when the temps started hovering at 200 instead of going on up. The temps never got over about 205 anyway, so I don't figure it mattered. It took a bit to get the 3 & 1/2 gallons boiling but when it did the thing really roared. I made a strap assembly similar to Lee Valley's except for the adjustable end which mine doesn't have. The strip came from Lowe's metal rod bin and is about 1 & 1/2" wide.

The piece steamed is Western Red Cedar 3/4x2" and 4' long and is quarter sawn. I just need about 34" of it so I have ends that will be cut off. Since I only have one form and no drying rack, the piece will stay on the form until tomorrow evening.

Dad was here to slap on clamps for me as I wrapped the piece and strap around the form. After steaming for the suggested 45 minutes it was not as limber as a wet noodle as some have said. But it is kiln dried and was not soaked. Firm hand pressure was plenty to bend it slowly to the form. It went fast with the help so it was on in about 2 minutes.

It appears that distortion with the large radius of about 1 & 1/2 feet is probably minimal. That is good as I don't know what I would use other than a sander to clean up the inside. It may still need some but wrinkling is not apparent while on the form. In fact it appears that the edges only have the grain raised a good bit. It came out of the steamer still looking pretty dry so it may be more of a "heat bend" than a true steam bend. It does appear to have worked though. Bending a 2' piece dry and cold on this form it barely started to bend before it went off like a shotgun breaking almost in two.

There are 7 more to do so I will build some sort of drying rack I think.

David

[Brad Schafer]

dave - i'm certainly no expert, but i did see a fellow making windsor chairs at a woodworks a few weeks ago. he had a piece of 6" capped PVC and a tea kettle for a "steamer". claimed he used this as his "demo setup", and that his setup at home was much larger. he said that the ability to bend a piece had to do with heat, not moisture (which kinda surprised me), and that elasticity was based to a great degree on how completely thru the piece was heated. ostensibly, the moisture is simply a "heat carrier".

it took his contraption about 45 minutes to get a "cane" ready to bend into a windsor chair back (a severe bend, imo) ... and a cane wasn't much more than an inch or so in diameter. perhaps your difficulty in bending had to do with the piece not being heated long enough.

he had (according to him) "around 50 or 60 seconds to complete the bending process, or (he'd) have to heat it again".

he also said that much of bending's success is derived from the quality of the form. and yours looks nice and solid.

looking forward to seeing how this progresses,

b

[Lee Schierer]

I used a piece of PVC for steam beneding and regretted it during the process. PVC softens at about 180 degrees and gets quite flexible about the time the wood has been steamed long enough to be halfway pliable. I wouldn't use PVC again if I do any steam beanding. Maybe the thicker wall stuff stays firmer longer, but since steam is 220 degrees, I'll use wood for the steam box in the future.

[David Rose]

Even thick walled PVC is suppose to have support on 3 sides or it can/will sag. I decided that I might as well build the box if I had to have 3/4 of one anyway.

Brad, the "rule" is 1 hour per 1" thickness of the wood. I thought I would try that first. Sometimes over steaming is as bad as under. Kiln dried wood is not suppose to resteam well at all, so I decided that if it broke it broke and I would try something different. Since it bent, though with some pressure, I am very happy. Well... if it *stays* bent I am "very happy". :) I think it will, but haven't pulled it yet. I didn't mean to sound complaining on the amount of force required. It wasn't that bad at all. It just wasn't the "wet noodle" that I read it could be. Of course, if that were the case what would it look like after clamping?

Some bending is done with just heat in some places and some types of wood.

I'll add more when I pull the piece tonight.

David

[Dean Baumgartner]

Even thick walled PVC is suppose to have support on 3 sides or it can/will sag. I decided that I might as well build the box if I had to have 3/4 of one anyway.

Brad, the "rule" is 1 hour per 1" thickness of the wood. I thought I would try that first. Sometimes over steaming is as bad as under. Kiln dried wood is not suppose to resteam well at all, so I decided that if it broke it broke and I would try something different. Since it bent, though with some pressure, I am very happy. Well... if it *stays* bent I am "very happy". :) I think it will, but haven't pulled it yet. I didn't mean to sound complaining on the amount of force required. It wasn't that bad at all. It just wasn't the "wet noodle" that I read it could be. Of course, if that were the case what would it look like after clamping?

Some bending is done with just heat in some places and some types of wood.

I'll add more when I pull the piece tonight.

David

David,
Interesting project. How long are you leaving the piece clamped to the form? I'm curious as to how well it will maintain the shape after un-clamping. Do you bend to the finished dimension or do you plan on some amount of spring back when you release the clamps?

Dean

[John Piwaron]

David,

I'm just workin' up to steam bending some stuff for myself. I've a ways to go however.

But there's one thing I'm really interested in, and that's how much water did you use up in the steamer? I ask because I bought one (1) electric tea kettle from Lee Valley, and if I need a lot of steam, I'll need another or bigger rig. At this time the largest object I can imagine doing is around 1.5 dia by 4 foot, and even then the amount of bend is not very great, certainly much less that a windsor part.

[Dennis Peacock]

David,

Let me know how the steam bending goes....I have often thought about trying my hand at bending but kept chickening out. I guess I'll have to try it soon.....Good work and keep posting as to your progress.

[David Rose]

OK interested parties, here's the latest. I am kind of impressed with this operation. But I've always been kind of easy to impress, so... ;) I popped the clamps a minute ago which is about 15 hours after it was clamped. I intended to get to it earlier, but LOML and the grocery store called and they won.

The springback is so minimal, as the pic shows, that the thing is actually tighter than I wanted! This is OK as all say it is much easier to straighten than to bend. But the piece seems no less rigid than it was originally. The actual radius that I want to fit is 21 inches. I built the form to a 19 inch radius. The inside 32" of the piece exactly fits the form! I am impressed!!! Oh, sorry I said that already. When I first pulled the board and strap from the form it really opened up. It had me a little worried. I had to drive the piece from the strap as with the ends being tight in the beginning and then having the wood piece ends compressed into them, they were *tight*! Once out of the strap it closed right back though.

The piece has about 0.010" impression of the holes in the strap and there is even less wrinkling on the inside. Folks, this is an amazing and fun process!

I will end up milling a 1" wide groove 1/4" deep in the outside face, so it will probably relax somewhat anyway.

Remember that this is a very soft wood so hardwoods will likely be different in several ways. They are not suppose to impress and wrinkle as badly and this wasn't bad at all. Hardwoods I would expect to require more bending force, but I don't know that.

I used about 2 and 1/2 gallons of water in the steamer, but I ran the big burner pretty much full tilt. At least the flames were licking up slightly over the lower edge of the can. I could have probably turned it way down. I created enough steam that the whole valley here is fogged in tonight. Maybe I had help with that. :cool: But a little kettle wouldn't have gotten me far at the rate I cranked it out. Someone said to have it really pouring out so I did my best. :D Next time I will shoot for a little moderation. I likely burned way too much propane too. I haven't checked the level yet.

While cutting, planing, sanding and reshaping wood with those methods leaves natural figure alone, this feels like changing the character of the wood without changing it's nature! I am awed! I guess you figured that out by now. :)

If the rest of the pieces go like this one, I will feel like I could build the Ark! That is... with Proper instruction of course. :D LOML came out for the Great Unbanding and was almost as awe struck as I. Then her mind started to work. Uh oh... She first said "chair arms", then came "a rocker!", then on and on. Like I said, uh oh. ;)

David

[Wes Bischel]

David,
That looks really cool! Steam bending is on my list of "Things to Try". (albeit lower down on the list) Thanks for taking the time to share your efforts. I may just have to move it up on the list!

Wes