Steam bending wood, my first wood steamer

[SwampDonkey]

Well, I'm building a sled and I need two skis from straight grained ash. Or at least that's the plan, the sled I mean. I will also bend 3 cross members that bend 90 degrees on the end for 16 inches, 24 inches between bends.

Here is my setup.



20 gallon drum for a boiler, sitting on stove. Attached to 3/4" metal spigot in the drum lid. Only needed 3 gallons or so for enough steam. Need to try to find a smaller can in my travels. But, it works for now after I got the boiling part worked out.   :

Can't boil water worth a darn.



Steam chest, 8 foot galvanized duct with 2" of spray foam insulation containing fire retardant when cured. Took 6 cans I think, at $8.50 a pop on sale. Pricey stuff. End plug is exterior plywood with flattened bottom edge to drain condensation from the chest and alleviate pressure, if any.

I have it temporarily suspended where it's at. Will build a proper spot some day. You can see the strings from the ceiling.



Steam hose from the boiler, 3/4" pipe. Hooks onto a spigot with a 2" cutout into the end plug. Siliconed to seal with roofing silicone, takes 250 F heat I think.



Full get up.



Test piece, notice I put a world of hurt on it with a twist to it. ;D



After bending past 90 degrees, there was failure on the back of the piece. If it weren't steamed it would have failed long before that.

All in all, a successful first run.

[Tom]

I'm very impressed!

Would fiber glass insulation have worked around the steam container/pipe?

[jim king]

SD:

A lifetime ago I worked for a wooden boat company in Peshtigo, Wisconsin.   We did a lot of steambending and your setup looks better than what was there.

[SwampDonkey]

I'm very impressed!

Would fiber glass insulation have worked around the steam container/pipe?

I'm not sure Tom. Duct has a seem, so you'd have to make sure the seem was sealed or you may have soggy insulation. Other than that, I suppose you could wrap duct tape around the fibre glass.

[Don_Papenburg]

You could use foil faced 'glass with the foil against the pipe and another layer with the foil out to keep the ichies contained.

[Lud]

There's a lot of info on bending. Fine Woodworking had some good articles in the last couple of years.   Use wood that was split or rived, not sawed.  And use a metal strap with blocks trapping the ends of the board being bent to keep it compressed.  Also, bend as far as you can easily to stretch the fibres, and then flip the board and you can achieve your bend easier.

[SwampDonkey]

Lud, yes I have some details from Wood Worker's Handbook about the strap and formers. That's what I went by. The strap would not be used in my case because I have 7 foot skis. Never thought about flipping the board though. My skis have to bend 16" upward on an 18"-20'ish curve. Going to make my ski formers today.

[Coon]

Hows the steaming and bending going, swamp?  How thick is the material that you are bending?  While doing the few different bending projects that I have done I have found that very straight grained quarter split wood (same as quarter sawn) gave the best results.  I have a steam box built for very large projects.  I can steam 12' long 2x12's for skiis if I need but it is a painstakingly slow project.  I use the steambox outside to keep rid of the moisture problems in a building.  Kinda a crude setup but it works..... Got a call a while back from a guy I know that wants some skiis made for a project he is doing.  Hasn't shown up with the 2x12's yet though....... kinda thinks he's having bit of trouble finding oak that big round these parts.... ;)....who'da thunk   eh eh

Brad.

[SwampDonkey]

Yeah, coon I'm over in the "Building an Arctic Snow Sled" thread. ;D

I found that flat sawed bent just as easy as quartered. I did a quartered stick yesterday for a ski. We'll see if flat sawed holds up I guess. Harold keeps warning me, but I did it anyway. :D My skis are 3/4" white ash. My top hand rails are 1" ash, but don't seem to need steaming, they don't bend on a strong curve, just gradual.

[SwampDonkey]

Well what's a guy to do? An 8 foot steamer, but a 12 foot member to be bent.

Well...........

Poke holes in the ends and stuff rags around the holes. ;D





End result, a 12 foot long piece of spaghetti. ;D She sure bent easy, musta been real hot in there this time. 7/8"  x 2" stock, cooked it extra long to make sure. ;D



Sitting in the former. 

[ronwood]

How long do you have to steam the wood?

[SwampDonkey]

Ron, the recipe is 1 hour per inch of thickness, timed when you see lots of steam bellowing out the ends and water dripping steady. That's what I go by. Sometimes I might have a piece in there 2.5 hours getting the conditions just right. I'm using wood for heat so you need good firewood (hard maple, beech oak, hickory) because as you load wood in the stove the temp goes down a few minutes until the wood is a glow. Sometimes it's good to have small sticks on hand so it doesn't interrupt the heat flow so much. My stove is stuffed full of hot coals when she's boiling good. With my boiler I can hear a crackling when the boil is rolling good inside the drum, and I can't put my hand on the end of that plastic water pipe. The steam chest metal is also hot hot. A continuous even heat would be quicker to get your constant steam rolling. Make sure there is no sag in your water line to trap the steam from water condensation. That's why I suspend my water pipe with strings from the ceiling, to take sag out when the pipe gets hot. It's a learning process for me to. ;D

[ronwood]

Thanks for the answer. I would like to try it sometime.
Ron

[SwampDonkey]

I've wanted one for years, opens up a whole lot of new projects. 

[SwampDonkey]

Hasn't shown up with the 2x12's yet though....... kinda thinks he's having bit of trouble finding oak that big round these parts.... ;)

Brad.

Well, down in Southeastern SK and southern MB (mostly Manitoba) there is bur oak (white oak) So, take a day trip and find a mill. ;D