transom material/thickness

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DSJ
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Joined: Tue Apr 06, 2010 8:54 am
Location: Thessalon, On.

transom material/thickness

Post by DSJ »

I've designed an 11.5' square stern canoe to haul on the racks on an ATV to get into some very small remote lakes for fishing.

It's similar in dimensions to a Peterborough autoboat or a sportpal/Radisson wide transom.
11'5 feet long. maximum beam is 39" and centre depth is about 12". the transom is 32" wide and 15" deep It's got a flat bottom and the sides are straight at the bow with progressively more tumblehome towards the stern.

Since it's going on top of a four-wheeler, light weight and compact length are important to get through some rough terrain on the way to the lakes. Although it willl be paddle-able, the main propulsion is planned be with oars or a small motor, either gas or electric.
My 18.5' white guide is just too long to haul this way.

I'm nearly finished stripping the hull and plan to install the stern after it comes off the molds.
I'm looking for something other than solid hardwood for the transom to keep the weight down.
any suggestions?
willo
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Location: Echo Bay ON.

Post by willo »

I would be tempted to use white cedar and a layer of glass on both sides. For what you describe , strength should not be an issue. If you wanted more strength you could use white spruce . It really depends on the power , 2-3 h.p should be fine I would think , I attach a 2h.p right to the gunnel on a Ranger , works great.
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Richard
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Location: Wales U.K.

Post by Richard »

Hi,
I'm no expert on timber, but I have used Meranti for decks and paddles and thwarts and have been pleased with the results. I'ts a mahogany species which is very light with a good colour. However, it is soft and needs protection from one or two layers of glass and epoxy. You could add extra layers where needed.
Good luck.

Richard
Rick in Pender Harbour
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transom material

Post by Rick in Pender Harbour »

Hi
I've built several cosine wherries to take a small outboard, using glassed 3/4 inch cedar transoms with doublers of fir epoxied to strengthen and thicken the area for the motor mount. I think in a canoe style hull a quarter knee on the bottom inside of the transom and the two quarter knees at the inwhales would be needed.
The fir was planed down to about 1/2 inch to give a finished thickness of 1.5 inches for all three layers.

Image

Not sure that the pic will work, if not e-mail me and I'll send some direct.
Rgds

Rick[/img]
Last edited by Rick in Pender Harbour on Mon Jan 17, 2011 1:26 pm, edited 1 time in total.
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Patricks Dad
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Location: Warrenville, Illinois

Post by Patricks Dad »

Rick, Very pretty boat!

BTW, the [/img] should be at the end rather than at the beginning of the image string...
Randy Pfeifer
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DSJ
Posts: 49
Joined: Tue Apr 06, 2010 8:54 am
Location: Thessalon, On.

Post by DSJ »

Thanks for the replies

I have lots of strips left so i'll laminate two layers of 1/4 inch strips together with the the strips in the second layer at 45 degrees to the first then fiberglass/ epoxy on both sides.

I plan to have a fairly stout keel on this boat, so i think a knee tying it to the transom willl probably give plenty of strength
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