pain in the butt outwhales!

samb

LOVES Wooden Canoes
On my OT HW I need mahogany outwhales. I’ve cut them and shaped them, given them a week in kerosene, steamed them and bent them and will now cut the ends off and maybe start again with the steaming. My problem was that the pieces did bend, but along the line of least resistance which meant putting a twist in the timber as much as a bend. The fact that I’m having to use sapele rather than ‘proper’ mahogany, and the fact that it’s kiln dried because that’s all I can (easily) get doesn’t help. Even with the bend I managed I see the start of splitting. I did manage to bend the inwhales, but they didn’t have the ‘L’ profile that is encouraging the twist.

As I see it my best / easiest alternatives would be:

Buy a different species of wood, machine, steam, bend and stain it: It would have to have a similar grain pattern rather than using ash (which I know I could bend but would not look right). Would cherry do the trick?

or

Machine the curved section out of solid and splice it in. – This would be straight forward enough but would it look wrong being carved from solid rather than bent?

What are your thoughts?

Sam
 
I agree, not the ideal wood. You might try the plastic bag method of steaming. You will likely have to remove the decks to do it, but the benefits are that you can clamp it directly onto the canoe reducing the twisting, you can bend while it is still steaming, and you can try the bend periodically and see if it will go or not. I was skeptical, but I am a believer now.

Here is a video showing the set up. You don't need to steam the whole rail. Just a four foot section or so at each end.

https://www.youtube.com/watch?v=--iPQIwSEJM
 
Thanks for that - looks promising, and if successful would mean I could splice in the middle and not have to worry about getting the length perfect. Would the hot polythene / wood affect the paint do you know?

Sam
 
I was worried about that some too, but it did not bother the paint at all. I still had a couple of coats of paint left to do when I bent the gunwales, so I figured I could deal with it if the paint was affected. There will be lots of steam and hot water condensate, so prepare for that and be careful.

Fitz.
 
I was talking to the people at www.islandfallscanoe.com and they said they said using mahogany is very very difficult because it is kiln dried. They said they have had great success with cherry wood and stained mahogany. I am considering purchasing a pair of pre-bent for 80$/each as steaming does not sound like fun to me.
 
I have pretty good luck with genuine /Honduran mahogany especially with a bend like the HW has. I did soak it for a week. Friends have used African to some degree, but getting that bend may be tough. I have not tried cherry.
 
I was talking to the people at www.islandfallscanoe.com and they said they said using mahogany is very very difficult because it is kiln dried. They said they have had great success with cherry wood and stained mahogany. I am considering purchasing a pair of pre-bent for 80$/each as steaming does not sound like fun to me.

Thanks for the thumbs up for cherry as a possibility. I'm going to try the boil in a bag method that Fitz suggests first as I already have the timber machined. The option to buy a pre -bent pair is not so good when you factor in shipping to the uk!
 
Steve:

I used the polyethylene bag material that comes on a roll and allows folks to make custom size bags. It comes in different widths, (I bought 3 inch, but could have used a larger dimension to fit my hose better). I used 6 mil. It is available on-line and at places like Staples. Search on "polyethylene" here on the forum. Greg Nolan did a piece about it.

Here are some sources too:

http://forums.wcha.org/showthread.php?11783-steam-bending-technique&highlight=polyethylene
 
I bought a roll of 500 gauge (might be a uk / European standard) - it was the heaviest I could get. I bought 2" tube which was not ideal - 3" would be better as I had trouble fitting the steam tube in alongside the timber.
I found it worked well having 2 layers of tube, one inside the other as just one layer got awfully soft in the heat and punctured easily. The second layer didn't soften that much, and I like to think it kept the heat in and made a difference.
I've done one side of the boat with a fair bit of success but I'll be pleased if the next boat I fix up has a flat shear line!

Sam
 
The bag method works very well. One idea you may want to consider is clamping horizontal planks across the inwales. That way you have control of the bend in the vertical and horizontal planes and minimizing twist. There was a really good demo at the 2014 Great Lakes Regional using this bag method. I do not know if any one took a video. If so it would be nice if it were posted. Honduras Mahogany is known to be hard to bend so you really want to use the steam method and the bag trick is possibly the best for fitting new outwales.
 
Also a 4" 6 mil 1000 ft roll of poly tubing from Uline is $70. In addition the roll at Staples is listed as being 1000 inches in length for about $65. So if that is not an error the Uline price is better.
 
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I've seen the plastic bag method in person and on YouTube. Gonna try it some day. (The YouTube I saw was on a boat with very little rise in the sheer. IMHO may well have been an easy bend just soakedwithout steam.)
I've had no success on African Mahogany. Never tried Philippine. I have tried a kerosene soakwith no success several years ago.
I have had good success with Honduran by clamping cross pieces across the gunwales and clamping a special jig to the decks to bend against.
My theory is soak long...4 days plus, steam HOT, and bend slow. Often I will kick the heat up for the last 15-20 minutes to ensure that it is hot. A great part of my success could be that I've acquired premium air dried mahogany.p
The bag method confounds me, although the success is well documented. Just can't see it getting hot enough.
But, like I said... I'm gonna try it one of these days
 
I agree, not the ideal wood. You might try the plastic bag method of steaming. You will likely have to remove the decks to do it, but the benefits are that you can clamp it directly onto the canoe reducing the twisting, you can bend while it is still steaming, and you can try the bend periodically and see if it will go or not. I was skeptical, but I am a believer now.

Here is a video showing the set up. You don't need to steam the whole rail. Just a four foot section or so at each end.

https://www.youtube.com/watch?v=--iPQIwSEJM

Fitz,

Thank you for this link. Another one of those great ideas.."Why didn't I think of that?"

I will use a plastic bag for steaming the white oak I am making outside stems from. I will still bend it to a form but I can clamp it hot and keep heating while it relaxes.

George
 
Here is the link to my discussion of my first experience, and Fitz's experience, with steaming in a poly tube:

http://forums.wcha.org/showthread.php?12999-STEAM-BENDING-IN-A-POLYETHYLENE-TUBE-part-1

Dave -- it gets hot enough if you use enough steam (a wallpaper remover steamer does not do the job for a long piece of wood) -- you are only steaming one piece of wood at a time. Probably not the way to go if you are steaming several ribs at a time.
 
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I agree with the timber across the inwales, the struggle I had was how to get a similar support to bend to where the deck was. I ended up with a series of pieces notched out to account for the profile of the deck and an arrangement of clamps. It all worked as far as my clamps could reach but not so good towards the end. Now the first lot of clamps are out of the way and temporary screws in place, I'm thinking of seeing if I can re-steam the last 5 inches or so.

Next time I'll put much more thought into putting something to bend against and support the outwales in the deck area.

Sam
 
I forgot to mention that I had an extra set of hands. I think that is a great help. I was bending and the other guy was clamping. It was Honduran mahogany (probably kiln dried, soaked for a week) on an OTCA. It was near freezing too. I thought my chances of success were slim at best. To say I was pleasantly surprised is a great understatement.

Sam: I took my decks out temporarily, bent the outwales, let dry and then re-installed everything. That allowed me to clamp without the decks in the way. Protect the inwale though.
 
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I too like the plastic bag steaming method. But I made my own bag out of plastic that is commonly sold in hardware or nursery stores. It's relatively thick stuff, 8 to 10 mil I think, comes in rolls, and is cheap. What I did is unroll 17' of the stuff (for a 16' canoe) and cut about an 18" strip out of it. Then I folded the plastic to form a 6" tube & Gorilla taped along the 17'. I then flattened out the tube at the seam and stapled over the tape at the seam to form structurally secure 'tube'. Then I got a propane turkey fryer rig and butchered the fryer pot's lid to accept a metal nipple fitting big enough to hold some radiator hose. I then fond the center of the 'tube' & cut a hole big enough to fit another nipple fitting - this one a 'T' fitting - and secured the fitting in the tube with more Gorilla tape. Hint: let the Gorilla tape 'cure' for a day or so to make it more heat resistant. More hints: Use several ply of newspapers under the pot lid to act as a gasket (cut a hole in the paper to let the steam reach the radiator hose). And use C-clamps - or a heavy rock - to hold the lid down tight. And the hose leading to the bag should slope 'up' or 'down' to allow condensed steam (water) to drain out - otherwise you'll get a water lock and lose all your pressure.

I found the steam bag method works great right on the canoe (I do it before canvassing) for gunnels that don't have extreme tip curves. Just clamp right on the canoe.

But for extreme tip curves I make a wooden 'form' shaped slightly more than needed. The form is also made so the top un-notched side of the gunnel touches the form. In addition I also use a flexible silicon strip heater. Granger has 'em - look for part # 6THP7, 120vac @ 24" x 1" @ 240 watts. So: soak the part for several days, then steam it, then carefully clamp it to the form - backing the part with a flexible metal ruler/yardstick as you clamp. Use clamps every few inches in a bend-clamp-bend-clamp manner. Let it cool down for a few hours. Then remove the clamps, place the strip heater between the form & the part, re-clamp, power up the heater for a few hours, then un-clamp the part & check the bend. Repeat clamping/heating until the bend is acceptable. And FYI, you could certainly do the initial bending with the strip heater in place, but unless you have a helper it's too much of a job for one person to handle alone.

The strip heater works so well because soaking allows water to get deep inside the part - it'll take many days to completely dry. By adding high heat supplied by the strip heater you're very efficiently re-steaming the wood using this inner moisture.

Also, I tend to use the above strip heater method on short - like 2' to 3' sections of gunnel. I then scarf cut the part with more material to make the complete gunnel. Since the wood is all the same the cut is usually barely noticeable.

And also, you'll have much less breakage if you form the notch after you bend the tips.

Anyway... some ideas.
 
Why not use a section of metal down spout as used in a house gutter system? It will last forever and not warp or soften.
Pathologist
 
When using the bag method you can clamp directly to the canoe with out removing the bag. Using a separate steam chamber allows the gunnel being steamed to lose heat when being moved and clamped. Much more efficient to use the bag and clamp in place.
 
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