Replies

1. 
   SawdustSteve | Sep 06, 2002 05:59pm | #1

   Joe... You COULD use two pieces of heavy angle iron to act as a break to bend the sheet metal to make your steam box.  A rawhide or rubber mallet, a couple of vise grip pliers  etc... and you're in business.  It mat be easier in the long run to go to a local shop that manufactures air conditioning ducts and inquire  about a price.  They have the proper tools and equipment to make the box 'air-tight'.  OR, could you use a standard size piece of ducting?? 

    SawdustSteve

2. 
   BenM | Sep 06, 2002 07:52pm | #2

   Why metal?  Metal is going to get hot.  Also, it's not as good an insulator as wood so you will need more heat input.

1. 
   woodherb | Sep 06, 2002 10:58pm | #3

   ben-

   I somehow think heating wood to being a temperature up to 180 degrees or 212 would pose a greater fire hazard and personal risk than heating a copper box or sheet metal.

   thanks

   joe clark

1. 
   chairman | Sep 06, 2002 11:12pm | #4

   Hi Joe

   I have a steaming box just that size made of 1x6 cedar fencing boards.  I use it to bend Winsor chair hoops.  I don't beleive there is any fire hazard at all with the steam box itself, it runs quite wet from the steam condensation, and 212 F is not very hot. I copied mine from the steam box at the John Campbell folk school. 

   It is very important that you seal the box somewhat to keep out the air.  The great density difference between air and steam causes steam to go up and air to intrude, much more than one would think.  My box is just nailed together.  The ends are sealed with tight fitting wooden doors of the same material as the box, with a hinge on the top and a handle to open them.  I set mine on a turkey cooker to get the steam. 

   The steamer is the greatest fire hazard.  I also have dowels through my box to hold the material off the bottom.  If you don't do this the steaming will be problematical.  When you steam make sure steam is leaking out of all the seams in the box. If not, you will get air in, and the steam bending will fail.

   Be super careful with the steam, you can get very badly burned when opening the box.

   Lou

1. 
   DennisS | Sep 07, 2002 01:06am | #6

   > ....Be super careful with the steam, you can get very badly burned when opening the box

   To which I would add...

   A pair of leather welding gloves is cheap insurance. Not only is the steam dangerous, the work pcs are pretty hot and you need to work fast.

   Dennis in Bellevue WA

   [email protected]

1. 
   BiotechBill | Sep 07, 2002 02:03am | #7

   I have used a steambox made from black PVC(?). It consisted of 2, 3 ft long pieces conected by a T fitting. Steam was fed in through the T and the ends had tight fitting caps. Holes were drilled in the bottom side of the PVC to ensure containment of the steam in the chamber. Once the steam came rolling out of the holes the box was ready to go. 45 min to steam 7/8 ths QS white oak for mission chair backs. The steam source was a NEW 5 gal gas can and a radiator hose to connect to the box. Also used dowels to keep the work suspended in the center of the PVC.

   Bill

   Edited 9/6/2002 7:05:30 PM ET by DRBILL62

2. 
   jhausch | Sep 07, 2002 02:17am | #8

   I am with the last guy - big 'ol piece of PVC with a screw-cap clean out at one end, regular end cap at the other.  They make 8" PVC but you will probably have to talk to a plumbing supply place to get the parts.

   Drilling across "off center" (I think my geometry teacher called that a "chord" and all diameters are chords but not all chords are diameters ;-)  will give you holes to thread thru dowel to support the work - and other areas to see the steam blowing out. Steelkilt Lives!

2. 
   DennisS | Sep 06, 2002 11:39pm | #5

   >....

   I somehow think heating wood to being a temperature up to 180 degrees or 212 would pose a greater fire hazard and personal risk than heating a copper box or sheet metal.

   Unless I missunderstand how you intend to design your steam box, there's no danger in catching wood afire with steam. Unless you're considering suspending your work over a long, thin vessel filled with water and heating the whole contraption.

   With a little scrounging and some rescoursfullness you could build a simple box from scraps of plywood, get some cheap flexible rubber hose, something like a tea kettle on a small propane buner and duct the steam into the box. You'll spend less fuel in shorter time generating enough steam to raise the temperature in the box to the desired level using this kind of setup. 

   Dennis in Bellevue WA

   [email protected]