Making contoured seats

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Charles G. Clark, Jr.
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Location: Huntsville, AL

Making contoured seats

Post by Charles G. Clark, Jr. »

I am going to make the seats for my canoe. I want to make contoured seats. Can someone out there tell me the radius of the curve of the seats? As I understand it, the drop in the seat is about 1 inch.

I caned the seat for my Wee Lassie. I plan to cane the seats for my Freedom 17 as well. I spaced the holes per Mac MacArthy's book for the Wee Lassie. I think I would like to space the holes a little closer to get a finer weave of the cane. Any recommendations?

Thanks.
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Pete in the Deep South
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Post by Pete in the Deep South »

I purchased contoured seats already made up from http://www.edscanoe.com.

Try a radius of about 18.5 in. ......that would be the solution for a middle ordinate of 1" and a chord lenght of 12" if my arithmetic is correct. :thinking
KG4YOL
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Pete in the Deep South
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Post by Pete in the Deep South »

I took a look at the purchased seats and the chord length should have been around 14". That would make the radius 25". :embarassed
KG4YOL
Charles G. Clark, Jr.
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Location: Huntsville, AL

Post by Charles G. Clark, Jr. »

Thanks.
paul
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Post by paul »

Charles,

Pls keep us (me) informed of your progress.
I am also attempting the same type of seat.

I am in the process of asking a friend plot a full size drawing with CAD, so i will let you know how my progress goes.

Paul
paul
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Post by paul »

I have a full size cad drawing (in PDF) based on the above dimensions estimated by Pete if anyone is interested.

I am still in process of transferring to my chosen fibre for the seat and finishing but it looks like it will work.

Paul
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Glen Smith
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Post by Glen Smith »

Paul, I will take you up on that kind offer. Please forward to glen@charlevoix.net .
Tim
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Post by Tim »

I would also like to take you up on that offer. Please forward them to tmann@keywestretaining.com

Thanks!
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Armin, Germany
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Post by Armin, Germany »

May be this is something interesting I found in a german forum:

http://good-times.webshots.com/album/55 ... v?start=12

Armin
Charles G. Clark, Jr.
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Location: Huntsville, AL

Post by Charles G. Clark, Jr. »

I have finally gotten around to starting the seats. I am making 3 seats. I am replacing the center thwart in my Freedom 17 with a seat.

The approach I settled on was to make the contour about 3 inches less than the width of the boat at the seat location. Each seat has a 1 inch drop.

I marked the seats dirrectly on the 1 1/2 inch by 2 inch ash balnks. The contour is on the 2-inch face. I marked the centerline and the top of each contour. For example, on the seat that has a 15 inch wide contour, I marked the centerline and then a line 7 1/2 inches to either side of the centerline. I marked a 1-inch drop on the centerline. I then used a spline to draw a fair curve through the three points--the top edge of the curve, the bottom of the curve at the centerline, and the other end at the top edge. I repeated the spline technique 3/4 inch below the first one. The result is a 3/4 inch by 1 1/2 seat frame member with the 1 inch drop for the contour.

I copied the markings from one seat frame member to another one. The pair will then be joined with mortise and tenoned cross pieces.

I repeated the process for each seat. I have not cut the seat parts out yet. I don't have a band saw so will be using a friend's. I will go over there this coming weekend.
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Doug
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Post by Doug »

May be of interest,
http://www.greenval.com/FAQbowsliderseat.html
(you can buy the plans)

Doug

.
"Some people hear the song in the quiet mist of a cold morning..... But for other people the song is loudest in the evening when they are sitting in front of a tent, basking in the camp fire's warmth. This is when I hear it loudest ...." BM
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hoz
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Post by hoz »

Charles G. Clark, Jr. wrote: I marked the seats dirrectly on the 1 1/2 inch by 2 inch ash balnks. The contour is on the 2-inch face. I marked the centerline and the top of each contour. .
Am I to under stand you are cutting the contoured frame from solid stock? Any curved seat I have seen was made from 1/4" laminated strips, stronger that way.

AT the least you may want to check the run of your grain. Wouldn't want to spend all that time only to suffer a break out.
someday I'll fly, someday I'll soar
Charles G. Clark, Jr.
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Post by Charles G. Clark, Jr. »

I am cutting from solid stock. I wrestled for some time about laminating. I tried to determine, from pictures, if the commercial seats are laminated. The pictures look like solid wood. Take a look at the picture at Ed's Canoe site.

http://www.edscanoe.com/index.html

I am concerned about the strength of the seat though. I am thinking that I will make the seat 1" rather than 3/4" thick.

Still, I haven't done anything that I can't change, yet. I welcome the opinions of my fellow builders. My decision is imminent though, since whatever I do I will do it this weekend.
Chuck
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Glen Smith
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Post by Glen Smith »

This is from Ed's Canoe website:
Ash, Walnut, or Cherry You decide..............All of our woods are solid and select. NO laminations, stains, just natural beauty.
However, I feel that using laminated rather than solid stock would allow you to use smaller dimensions thus lower weight. I think you need to carefully select lumber with a good grain structure for this type of project to eliminate risk of breakage.
Charles G. Clark, Jr.
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Joined: Tue Sep 12, 2006 5:06 pm
Location: Huntsville, AL

Post by Charles G. Clark, Jr. »

I have done laminations before. I am fairly comfortable doing them. Therefore, since I do have concerns about the strength of the solid seat cut across the grain, I will switch to building laminated seat parts. It may not look as pretty as solid, but it does solve several concerns that I have had.
:thinking
I appreciate the responses I have received so far. I will keep you posted on the outcome. I should be able to make the lamination forms Friday and glue up the seat rails on Saturday. Since I will use epoxy for the laminating glue, it will be the middle of next week before I can finish machining the seat parts.
Chuck
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