Setups for Steam Bending

[CherokeeKC]

Can you all describe some of your different setups for steam bending a bow?  I need to steam bend a roughed out bow to make it straight side to side but will probably use it to reflex tips etc. in the future.

Thanks
K.C.

[Pat B]

What wood is it and is it seasoned?  I use dry heat for most of my straightening and bending anymore.   When I did use steam my set up was a large diameter pot filled with water and aluminum foil over the area to be steamed and pot and around the stave where it comes over the pot to prevent scorchinhg from around the pot. Thirty to 45 minutes of steaming and quickly to the form and clamps.    If your wood is seasoned seal the back and belly well with shellac(or the area to be straightened/bent). Shellac can take the moisture and heat and still seal the wood from most of the moisture.

[wally]

Hi Pat
   I've tried several times to dry heat bend but usually end up with a very  dried wood that cracks easily.
I've since used to steam and the wood bends easier. I've bent well seasoned elm and hawthorn.
You say shellac back and belly to protect wood. If you don't (I didn't) what can happen?
If you use dry heat I want to know why I can't? big question.
I usually steam over a boiling pot of water and cover with cooking foil.

[Pat B]

Wally, I've been more successful with dry heat than steam. I use oil on the wood with dry heat so to not dry it out too much, plus I think it holds the heat longer and distributes it more evenly. With steam you have a narrow window of time from steam to form and I found the wood would cool quicker than I could work. With dry heat I can keep heat on the wood until the the wood is formed to my needs. I work mostly with osage and it reacts well to dry heat. With some white woods I haven't had as much luck. Hickory recurves seem to uncurl over time. Steam or boiling might be the trick there or forming hickory and other whitewoods while green and let them cure to hold the bend. With a submersable bending form and a big enough pot of boiling water it would be possible.
 If you introduce moisture to already dry wood you can cause checking when the wood dries again. The shellac will help keep most of the moisture out.

[Del the cat]

I use an old wallpaper steamer, they are cheap (£30) and have a nice flexible hose. I made a steam chest with some offcuts of insulation board (the expanded foam sort wthat has a thin aluminium coating either side. The board was just cut with a knife and glued together with some caulk and bound with duct tape. You can punch holes in the board easilly to take a bow at any angle.
To me the big advantages of steam are.
1. You can heat a long bit of wood all at once to an exact temperature.
2. It doesn't dry the wood.
I know some people say steaming causes checking or dries the wood, but I don't really see this myself, it's more even, gentle and controlled.
Also seems quicker and easier, set it up, wait for steam, go have a cup of tea/watch TV, come back half an hour later, slap it on the former quick. Ha yes that's the down side, you have to get it on the former quick, unless you lash up the steam chest around the former.
I think dry heat comes ito it's own if you are bending and heat treating at the same time, the bend is also less likely to shift back if you get it up really hot and heat treat.
Del
PS There's a pic on the 'other stuff' page of my website (click the globe symbol under my username)

[Grunt]

I've had varying results with steam. If you go slow dry heat seems to work a bit better. My steam set up is 3 two ft joints of 6" stovepipe with a T inserted after the first joint. The ends are fitted with removable caps with holes drilled in the caps. I suspend the whole thing from a set of sawhorses with the bottom of the T pointing down. Place a hotplate with a big coffee can under and line up with the bottom of the T. Tinfoil a sleeve from the can to the T. I drape a packing blanket over the set up to keep the heat in. It takes about an hour to get things steamed and ready to bend. Got to be set up to bend things MORE than you think the bend should be. I usually have clamps already sized and the bow marked with colored chalk so I can move fast. The bow will spring back a bit after steaming. I am liking dry heat more cause you don't have to try and figure out how much the bow will spring back. I have not tried boiling the parts to be bent but that technique is on the list for me to learn. Have fun!!

[CherokeeKC]

Pat its the piece of Privet im messing with and yes its been seasoned for about a year and a half. 

[wally]

First a big thank you for all advice so far.
I looked up Del the Cat's website and it is just great. His tillering videos are the best I've ever seen, and the other stuff is good too. Thanks Del.It's worth looking up, just press the world link under his name Del the Cat.
Steam bending V dry heat bending has me confused as people have had success either way. I think maybe I was too impatient and didn't let the heat 'soak in' to the innermost fibres. I'm trying again on a new piece of wood for my Hupo bow
further questions though
I've heard mentioned boiling, does this mean actually immersing wood and boiling it? Is there advantage over steaming?
After steaming my last bow a lot of colour was left in the water, I suppose the tannin in the wood. Would that change the colour of that section of wood? It doesn't appear so, but the bow broke so I didn't get it to smooth finish.

BTW I just heat treated my ash gull wing bow's belly to a nice burnished dark brown using a heat gun. It's hopefully going to look good polished up

[Gordon]

I only use steam when I have to make a radical bend or am pressing a handle in order to align the string. Otherwise I prefer dry heat. The trick to using dry heat is go slow and gradually increase the bend. It took me a long time to figure that out, but once I did I experienced much better success. For what it is worth, here is a picture of my setup. In this case I am tempering the belly as well as inducing reflex.

[kentowl]

Struggling with a kinky oak stave on my first effort, I tried the boiling pot with and without aluminum foil,  no joy. A friend donated an old wallpaper steamer to the effort. I tried putting the bow in a PVC pipe, and running the hose in one end. With the pipe vertical, exhaust steam starting soaking the ceiling insulation. So I set it horizontal. I found the steam cooling down in the hose, so then I tried routing the hose inside the pipe. This kept the steam hot, but it was awkward getting everything inside- and even more awkward trying to get the bow out and clamped in time. What I really wanted was an enclosure that would fit around my bow form and clamps; one that I could move out of the way, adjust clamps and set back.

The answer for me was a roll of AC duct insulating blanket left over from our central AC install. This is waterproof, lightweight, cuts and shapes easily, and is convenient to roll up and store out of the way. You should be able to get a scrap piece wherever someone is installing AC - a 2'x6' piece will completely enclose a bow.