Kerfing for difficult gunwale bends?

Ask your questions here. Guests welcome to post!
Post Reply
LesForgue
Posts: 140
Joined: Mon Sep 12, 2011 6:29 pm
Type of boat I like: JEM Trapper by Matt
Location: Chicago
Contact:

Kerfing for difficult gunwale bends?

Post by LesForgue » Tue Feb 04, 2014 3:47 pm

As noted in Matt's instructions, The Trapper canoe has what could be a difficult bend at the ends of the gunwales.
I had an uncle who used to kerf boards and sticks to bend them.
Would kerfing be okay on a major structural piece such a gunwales?
Or would it weaken it too much?
I'm thinking epoxy saturation would restore any strength/integrity lost to kerfing - Please correct me if I'm wrong about that.
Image

OnkaBob
Posts: 388
Joined: Fri Jul 18, 2008 10:12 am
Type of boat I like: <-- Please read instructions to the left and delete this text. Then, tell us what type boat you like! :-)
Location: Seaford, South Oz

Re: Kerfing for difficult gunwale bends?

Post by OnkaBob » Wed Feb 05, 2014 2:53 am

Not sure but I suspect that with the direction of the stresses involved it would be OK.

I would laminate 2 thinner pieces but that's just personal preference.
Cheers, Bob

Laker 13 - christened and slimed (just).
Laker accessories underway.

LesForgue
Posts: 140
Joined: Mon Sep 12, 2011 6:29 pm
Type of boat I like: JEM Trapper by Matt
Location: Chicago
Contact:

Re: Kerfing for difficult gunwale bends?

Post by LesForgue » Wed Feb 05, 2014 4:47 pm

Thanks Bob,
I will try to force the bends without kerfing and only try kerfing as a last resort.
I have no table or band saw,; but with proper jigging probably I could make thin strips for lamination with my hand held circular saw; there at least 2 maybe 3 Trapper builds journaled on this forum so I know some have successfully bent the gunnels all the way to the end of the bow.
One factor is that it is hard to find long pieces truly clear of knots and at a knot they will likely break rather than bend no matter how thin the strip is - kerfing might make a piece with knots work okay.

and Matt gives the tip of bending the gunnel far as it will go and leaving it like that for some days, then bending it more and again leaving it a while, then maybe it's ready to do the complete bend. "Training" the wood strip over time.

tx river rat
Posts: 988
Joined: Wed Feb 21, 2007 10:48 pm
Type of boat I like: <-- Please read instructions to the left and delete this text. Then, tell us what type boat you like! :-)
Location: Tx

Re: Kerfing for difficult gunwale bends?

Post by tx river rat » Wed Feb 05, 2014 11:31 pm

Borrow your wife's hair dryer , and heat the wood as you bend them, I have done this with stubborn pieces before.
Ron

User avatar
jem
Site Admin
Posts: 4864
Joined: Fri Jun 18, 2004 8:14 pm
Type of boat I like: Wooden
Location: Greensboro, NC
Contact:

Re: Kerfing for difficult gunwale bends?

Post by jem » Thu Feb 06, 2014 7:20 am

Kerfing would be fine so long as you fill in the gaps.

Hair drier or heat gun will help the wood bend. Careful not to scorch it.
-Matt. Designer.

User avatar
Mick
Posts: 133
Joined: Fri Feb 25, 2011 4:26 am
Type of boat I like: Kayaks and canoes
Location: Fraser Coast, Queensland, Australia

Re: Kerfing for difficult gunwale bends?

Post by Mick » Fri Feb 07, 2014 8:51 am

G'day Les,

Have you thought about steam bending your timber?

http://www.thomasnet.com/articles/proce ... steam-wood

Post Reply