Bolting seats to gunwhales

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tom in caledonia
Posts: 45
Joined: Tue Jul 20, 2004 1:13 pm
Location: Caledonia ON

Bolting seats to gunwhales

Post by tom in caledonia »

Hi everyone,
I'm at the stage of bolting the seats to the gunnels and have come across a bit of a problem. I'm making a Redbird which has a fair amount of tumblehome. (I also added one strip to the shearline to make things worse). This results in some degree of bevel in the gunnels, especially at the back end of the rear seat. The carriage bolt heads will therefore sit flat on the gunnel only if the hole is drilled perpendicular to the same bevel. This would result in the bolts and spacers to be angled. It looks to me like Canoecraft portrays the bolts as being installed fairly plumb but the gunnels in the photos don't have the degree of bevel that mine do. Has anyone come across this problem before and what did you do? Should I have planed the gunnels flat i.e. taken the bevel away?
canoeblderinmt
Posts: 415
Joined: Sat Jul 03, 2004 12:04 pm
Location: Butte, MT

Post by canoeblderinmt »

Tom,
Try filing down the heads on the carriage bolts by about 1/3 to 1/2. There will still be plenty of grab, but less problem with your bevel/tumblehome. Chuck the bolts in a drill press if you have one to make this job easier. Remember to thread a nut on first to chase the flattened threads from the drill chuck. And don't be afraid to sink the heads a bit into the gunwale.

Greg
" Choose to chance the rapids, Dare to dance the tide..."
tom in caledonia
Posts: 45
Joined: Tue Jul 20, 2004 1:13 pm
Location: Caledonia ON

Post by tom in caledonia »

Thanks Greg. I may try that. I was even considering putting a slight bend in the bolt just where it exits the bottom of the inwale. I don't want to compromise the strength of the bolt though. The thing that bothers me, is that I want to drill through the inwale in such a way as to maximize the strength of the wood in this area. If I drill straight down through it, the exit hole won't be in the centre of the inwale any more. It will be offset resulting in less wood surrounding the hole on one side. I'll have to think about this one.
canoeblderinmt
Posts: 415
Joined: Sat Jul 03, 2004 12:04 pm
Location: Butte, MT

Post by canoeblderinmt »

Tom,
I added tumblehome to my modified White Guide by pulling in the sides from 41" to 36". It really curves, and the gunwhales are at like an 11 degree angle. I cut my seats wide and mounted them low, allowing me to come almost straight down with the bolts. I left enough room for my feet to fit under, but I only had to bend the bolts a little bit. If you haven't cut your seats yet, consider running them to within about 1/4" of the sides and hang them, rather than bolting directly to the gunwale(if that's what you are doing?).

If you are still concerned with there being enough purchase on the gunwale, consider epoxy glueing a scab under the gunwale where the bolts go thru.

Greg
" Choose to chance the rapids, Dare to dance the tide..."
tom in caledonia
Posts: 45
Joined: Tue Jul 20, 2004 1:13 pm
Location: Caledonia ON

Post by tom in caledonia »

I'm hanging my seats from the gunwales with ~2" spacers. I've pretty much cut my seats to fit tight to the hull. Do most people do this or leave space between seat and hull? Good idea WRT the scabs, I think that I may do that. Thanks.
Rob from Hamilton
Posts: 47
Joined: Fri May 21, 2004 9:09 pm

Hanging Seats in your Redbird

Post by Rob from Hamilton »

I built a Redbird a few years ago, and I put my seat bolts in on an angle, matching the tumblehome. ( I put an extra strip on too.) I also used about 2" spacers, but used the one piece spacers, rather than the "dowel type" spacers. (Probably makes no difference)
The bolts go through my seats at a slight angle, but that's no problem. I've tightened them so the heads are just slightly sunk into the gunnel. I didn't want to bend my bolts.
Also, I was always told to cut the seats just shy of the boat edge, so they don't rub. I'm not really sure if it matters that much.

Rob from Hamilton ON
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Glen Smith
Posts: 3719
Joined: Sat May 08, 2004 9:08 am
Location: Baie-St-Paul, Quebec, Canada

Post by Glen Smith »

Leave a space between the seat members and the hull so there won't be any rubbing between the two. One straight sided canoes I leave maybe 1/16" because making that gap larger would leave very little wood between the hardware and the hull. On a tumblehomed hull I leave about 1/4" because there is more wood between the hardware and the hull so I can afford to cut more off. When building a hull with tumblehome you should bevel the inwale face that is touching the hull so the inwale top is level. That would have solved your dilemna.
tom in caledonia
Posts: 45
Joined: Tue Jul 20, 2004 1:13 pm
Location: Caledonia ON

Post by tom in caledonia »

Thanks for your replies guys. Rob, are you in Hamilton ON? I'd love to take a look at your Redbird if you are. What kind of wood did you use for your 1 piece spacers? Dimensions?
Thanks Glen, now I know. I'll keep that in mind for the next one and I can still leave space between hull and seats on this one.

Regards,
Tom
Rob from Hamilton
Posts: 47
Joined: Fri May 21, 2004 9:09 pm

Redbird seat hangers etc

Post by Rob from Hamilton »

Hi Tom,
Yes we are just down the road from you, in Hamilton, not too far from Upper James and Rymal Road. You can come see our Redbird if you want. She's still hanging up in the garage right now. Let me know if you want to come down and see it. We can get it down for you.

We just used cedar for the spacers. Roughly 2" x the seat length x maybe 5/4"? I forget. We've had no problems at all. We built a Bob's last summer and used the same method. I think I like it better than the dowel type seat hangers.
tom in caledonia
Posts: 45
Joined: Tue Jul 20, 2004 1:13 pm
Location: Caledonia ON

Post by tom in caledonia »

Morning Rob. Just got back from Calgary, hence the late reply. I'd like to see your canoe sometime. I'll contact you shortly to set up a time. Thanks.
Rob from Hamilton
Posts: 47
Joined: Fri May 21, 2004 9:09 pm

Redbird

Post by Rob from Hamilton »

Hi Tom,
I'll be around for most of the weekend, but not Sunday morning. There's a Corvette show in Port Dover, and my friend has his car there, so we're going to see him. Let me know when you want to come down. Maybe you can leave me your email address here. (?)
Rob from Hamilton
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