Bending ash unsteamed

Roger Tulk

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St. Catharines, Ontario, Canada
I'll be making gunwales and inwales for a16' fibreglass canoe this summer. I'm thinkiinng that if I make the gunwales ½" thick, I should be able to bend them around the curve of a canoe this size without going to the trouble of steaming them. Eh? I plan to secure them with screws through the inwales and hull, into the gunwales. This is the only beniding that I will have to do. I'm thinking that having looked at some bow bending sites and finding that bowyers don't steam their staves unless they are making recurve bows, I should b e OK without the extra step of steaming.

Does this work for you?
 
½" thick - but how wide?

Don't forget that you'll be bending them in two planes - both vertically from bow to stern, and laterally as the hull widens in the middle.

Steaming probably won't be necessary, but you might need to soak them first. Also, air dried stock bends better than kiln dried.
 
Steaming tends to relieve stresses when used to bend wood. Dry bending does not. Residual stresses frequently take time to release, sometimes not gently. Be careful.
 
Thanks very much, guys. So, if I soaked the ash in very hot (160F) tap water for an hour or so, would that do the trick?

It probably would - but how do you intend keeping that much water at 160° for that long?

I'm assuming the gunwales will be one piece, so they'll be about 20 feet long prior to trimming, right? That's a lot of wet wood to handle. Better have a couple friends - and about 50 clamps - on hand before you start!
 
It probably would - but how do you intend keeping that much water at 160° for that long?

I'm assuming the gunwales will be one piece, so they'll be about 20 feet long prior to trimming, right? That's a lot of wet wood to handle. Better have a couple friends - and about 50 clamps - on hand before you start!

I've got the clamps. :thumb: I'm going to make the parts in two pieces that will be glued and screwed together during building. This will avoid some problems I've had with trying to glue the parts together (with a 1 in 7 slant joint, and later with a very clever locking joint that didnt' work, either.)

The canoe has a very flat profile along the sides, so the 1¼" width of the wood shouldn't be too much of a problem. I hope.

I will keep the water hot by keeping it running through a short length of hose from the laundry room. We have a huge tank that accommodates my son's 20-minute scalding showers, so it should work out. I can see some possible issues, i.e. how to keep the wood wet and warm during the process of clamping it along the sides. as it will require considerable time to do it, lining up and drilling and driving 64 screws (minimum) while the wood is still pliable, what to do about small children being swept away by the stream created by the soaking device, disposing of the soaking device as I won't be able to store it, etc., etc.
 
Depending on the upward curve at bow and stern, you can likely bend the gunwales dry, without any heat. Just screw them on. I've done that with epoxied 1:8 scarf joined ash gunwales 1" tall, 3/8" - 1/2" wide, and 18' long.

If your stems curve enough that you do need heat, only the bow and stern will need it; you can focus on one at a time, bending around a form to get them approximately right. After they cool and dry, you can take your time installing them, and the screws will hold them in place. Note if you boil them that, as long as the wood is not too dry (air dry level,) it's the heat more than the moisture that's helping you to bend.
 
Roger why not build yourself a very basic steam box.
http://www.google.ca/search?hl=en&s...26.1325.R8VHPsM-k7o#biv=i|2;d|jcA3qXQv6qIl5M:

For what you doing it dont need to be fancy just long. You could get away with some borg construction material and literally just nail it in a square. Get a old kettle from the thrift stores and hook it up (naturally outside when the weather warms) with a bit of pipe check habitat for humanity restore it. Perhaps get everything u need from them.
Sometimes the best route is a bit longer.
Other thing i can think of is select your ash pieces carefully. I have had some ash in the past that did not have an appropriate grain pattern to suit bending. Depends how its been cut and cut again for your strips.



sent from s4
 
Meant to add if u happen to know someone close that has a turkey or fish frier then something like that can be used as a source for steam when outdoors. Just make a custom wooden lid with a hole and adapter for hose in it. Makes it possible to work anwhere.


sent from s4
 
You very well might be able to bend the ash just by heating it up with a heat gun. This is one way to re-curve self-bow tips to reduce string follow. Just be careful to not burn the wood unless you want that primitive look. This also might reduce the issue with shrinkage in the glue joints if you use water or steam.
 
Another option would be to use 2 1/4" strips and glue them together in lamination to get the 1/2" inside and out. Sure it's an extra few steps but if you rip them out of the same board you probably won't be able to see the glue line with the grain matching up. Guaranteed to bend easier.
 
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