Bending Wood

[Guest]

Doug, I am vicariously enjoying your travails with fitting the rabbeted gunwales on the Rob Roy.

Gawd knows how those short gunwales were bent into place and installed OEM in the factory. I’d love to hear a Charlie Wilson description; there must be some secret technique.

The shorter length of the wales certainly eliminates some gentle bend leverage; trying to achieve that curve and sweep with a 17 foot length of ash is easier than forcing a 6 foot piece.

But I think another issue may have been the age and dryness of the “new” gunwale materials. Those were replacement wood gunwales a previous owner had purchased for a Malecite, and between when they were milled, sat at MRC, shipped to the original purchaser and sat with you I expect the moisture content was as low as it was going to get.

I brought my the PVC pipe down with the soaking wood and literally had to tap the top cap off. To my dismay the wood had floated up so the last 3" or so were dry, oh yeah dumbass wood floats!,

I have been trying to convince you that wood floats for several years. See past conversations about the effectiveness of “DIY rudders. . . made of wood”.

Stick a length of dowel in the PVC pipe and force the gunwales to remain fully submerged for the next set. I need to think of some package I can mail you with a “WOOD FLOAT DUMBASS” label.

During a dry fit on the hull these gunwales creaked like a SOB and I thought they break but this time they just bent without any protest. Sweet! After talking with Mr. McCrea, who knows as little about this as I do, the topic of wood drying and twisting came into play.

To be fair I prefaced any concern raised or comment made with “I don’t know nothing about this, but. . . “.

Today my total knowledge of soak bending wood gunwales comes from DougD. I won’t be adding that notation to my resume.

So now it's just a waiting game of drying out and the wood holding memory and keep the fingers crossed it works.

So, asking the folks who have done this, how long will it take for the gunwales to “dry out” and hold their curved shape, assuming Doug’s New Hampshire winter temperatures?

 

[Mihun09]

Dry out fairly fast, hold the bend, well, how old are you? Even after a week there is usually a tad spring back especially when using harder woods. YMMV.

Consider a 100 year old white cedar rib will lose it's shape if removed from a boat, the wood will relax still to a degree.

 

[Guest]

Here's pics of what I did.


http://picasaweb.google.com/11565649...32/BendingWood

Doug, I especially enjoyed dialogue in the little video snippet (click on the last photo, turn volume up)

I’m pretty sure the caller says “I’m not gonna do many beers in the morning. . . . “

That doesn’t sound like me in either intonation or intent.

 

[dave0]

The Results:

I was really hoping for a better turnout but something just wasn't right. I took the gunwales out of the jig and of course they bounced back like I knew they would but they did have some bend. What happened next took me by surprise and disgust. I put some weight on them to see how easy they would bend and all I heard was cracking, NO NOT Creaking, cracking. I know that sound all to well. By now I had the other set of gunwales soaking for 7 days and brought them out. Same thing without putting them in the jig, crack, crack, crack. I threw them in the corner where they will sit for as long as I have this bad taste in my mouth.

A little history is I got these gunwales in a sale on my Kevlar Malecite and I have absolutely no idea how old they were, certainly looked new to me. I have no idea how long they sat in a factory, at the previous owners house but do know they sat in my shed for over a year. Maybe I should have steamed them but I just don't want a steam box right now. In the past putting 16' gunwales on, factory or milled by me, has not been a problem but these 6' and change ones have been a real chore.

It's back to the drawing board and since I need to re-gunwale another hull I'm going to go the route I've taken for years now. Buy a plank of ash from Goosebay Lumber, mill out what I need and go from there. Fork the rabbet, that's nothing in my book but just one more PITA to deal with and besides I don't have the tools to mill it out. This isn't a tripping boat and I can lay a bead of expoy on the sheer line if need be before I put the gunwales on. Many of my other hulls have lasted for years doing this.

So there's the story of my attempt at bending wood for this hull.

 

[Alan Gage]

I threw them in the corner where they will sit for as long as I have this bad taste in my mouth.

I think we all know how you feel and it sucks.

Plans B and C sound good though and, if your shop is anything like mine, having to resort to them is the norm so that's pretty much just as good as succeeding with plan A.

Alan

 

[Mihun09]

Although we don't have a Dado set we still use the table saw to cut the rabbets. We just go as deep as we need then chisel about whatever gets left.

It sounds like you wood may have been very dry and soaking will only do so good or perhaps the wood was cracked already. Difficult to say.

 

[Jim Dodd]

All is not lost Grasshopper, for in failing you have learned a great and valuable lesson! Sorry The Old Kung-Foo show came to mind.

I hate like heck when things don't work as I planned. That's why I keep building!
I'll keep trying until I get it right !

Jim

 

[Boatman53]

I couldn't tell you how many ribs I've broken even with steaming (big boat ribs, not canoe). I routinely prep about 25% more stock than I need to account for breakage. Mine usually end up as kindling unless the damage was really spectacular, in that case I save it to show people that you don't always get it right the first time.
Jim

 

[Fitz]

Here is my polybag rig for gunwales. This is Honduran mahogany which is a bugger to bend. I soaked it for a week and then bagged it. This was in December at about 35F. I figured my chances of getting it to bend were slim at best, but after about 40 minutes in the bag it worked like a charm. I had a helper and clamped it on the sheer bag and all. The beauty of the system is you can periodically try the bend and see if it my go without taking the piece off the steam and there is no cooling down of the piece while you clamp.

 

[Guest]

It sounds like you wood may have been very dry and soaking will only do so good .

That is part A of my guess as well. The gunwales were replacements ordered by the owner of a Malecite Doug bought, so there is a lot of unknown history. How long did they sit with MRC after being milled + How long did the Malecite’s owner have them + a year two that Doug had them.

Part A, very dry wood.

But I think the short length of the gunwales on a Rob Roy is Part B. The gunwales on the RR are a bit over 6 feet long, versus 16 or 17 feet on a canoe. Inducing the needed bend in such a short length might well be problematic.

I have an MR Independence that I rerailed with beefy wood gunwales year ago. That was the first canoe I ever regunwaled; I built both the inwale and outwale oversized and they went on easily enough without any ominous creaking or cracking noises.

There is no rabbet on those gunwales and aesthetically the canoe looks fine, with just a faint thin line of hull visible between the sandwich.

I am curious about how Bell managed to install gunwales on the Rob Roy. Bell must have had some method that allowed the gunwales to be installed without excessive time, effort and wastage.

Call out to Charlie Wilson – How did Bell do it?