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Partial Don Hill Plans problem

Posted by SugarCreek 
Partial Don Hill Plans problem
September 06, 2017 01:42PM
I purchased instructions to build a 17’ x 54” Tatman drift boat, along with pre-assembled ribs, stem and transom. Looks like the 17 x 52 Don Hill and Baker drift boats are pretty much the same plan. What I got is old stuff, been laying in someone’s shop for 15 years or more. The instructions assume work with a complete set of pre-cut pieces so I do not have plans for the floor or sides. Today, I found someone drew the sheer line on each rib, so I took those measurements off, laid out a full size drawing on my concrete garage floor and marked up a drawing that was in the instructions for location of each of 9 ribs. It looks like the sheer line is 17’ even and the distance from front of the stem to the rear of the transom is 14’ 2”. I have added the height of the sides as I calculated at each rib and also at the foot of the stem.

It seems I should be able to build this boat from plascore by the stitch and glue method. I would cut sides according to the drawing, attaching to the stem, transom and 5th rib, adding in the rest of the ribs. Once I true up the frames and sides, perhaps on a strong back, I can lay over a piece of plascore for the bottom, trace out and cut.

I am looking for someone who can tell me I have my side dimensions right, or at least so close it does not matter. Once I know that I am confident ordering the plascore and other building materials. From what I can see from many years of posts on the forum, I could pre-glass the outsides of the sides, before attaching the stem and transom. Lay down, trace and cut the bottom. Preglass the inside surface of the bottom, and glue to the lower edge of the sides. I plan to use the pre-made ribs as a temporary frame. From there, 2 or three layers on the bottom using 12 oz or heavier glass, a strip of 3” biaxial tape on the chines in and out, followed by a 6” biaxial strip, and two or more layers on the sides. 1” plascore for the bottom, and 3?4” sides.

Am I on the right track? Not having done this before, I want to know the basic shape/profile of this boat will be true to the original design.

I have been looking through many years of posts on your forum. Great stuff! Thanks for your help.







Re: Partial Don Hill Plans problem
September 06, 2017 02:23PM
This is a style of drift boat whose side panels are high at the downstream end and lower at the upstream end, near the transom.

We all build boats that way but mine tend to be less so--less front and rear difference in side height. You can't change that because (if I read this right) your ribs are alreay built. No problem. It will be a great boat. You didn't give the bottom width of each rib so it's hard to judge what the bottom profile would be. I only mention it because boats of that style (much higher in front) tended to be designed for a payload of one OR two passengers on the front seat with NO ONE sitting behind the rower. That configuration is good for bait fishing and/or pulling plugs. It's also the most stable white water configuration. But a boat like that doesn't usually work so well in fly fishing mode, where one passenger is placed behind the rower.

I could say that more difinitively if you gave the bottom widths at each rib location.

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It seems likely this boat was meant to be built with side panels made by scarfing two 4x8 sheets together. You lose 2 or 2-1/2" inches to the scarf joint when you put two sheets together, end to end with plywood, so a panel like that would likely be 190" inches long.

You don't show the dimensions for the transom and stem cut out triangles, on that side panel. Perhaps if you made snap lines on your shop floor for a 48" inches by 190" inches rectangle you could experiment with superimposing the above dimensions onto the snap line rectangle.

Measuring from one end the first triangle cut out for the transom angle looks like it would be 8" to 10" in from the end.

I'll work with the figures a bit and post some more thoughts in a subsequent post. This is an interesting puzzle.



Re: Partial Don Hill Plans problem
September 06, 2017 05:02PM
Ah. Also. If you get side panels built and marked you than then attach, perhaps with drywall screws, the side panels to the ribs, as marked.

Then attach stem and transom. Viola. It looks like a boat without a bottom. The next step is critical. You have to straighten the assembly so the center of each rib, top and bottom, follows a center line.

Then you can make a 4x16 foot bottom panel and put it on top the upside down hull. Put weight (drywall mud buckets perhaps) at the ends of the bottom panel to weight it down tight.

Mark the edges from below with a pencil, where the chine meets the still square bottom panel. Cut it out with skillsaw set to an approximate angle.

Now stitch it on.
Re: Partial Don Hill Plans problem
September 06, 2017 10:14PM
Exactly, I figure if I use the prebuilt ribs I have as a temporary form, I don't need a pattern for the bottom. I assemble the sides, stem and transom and trace the bottom. I am most interested at this point in knowing that the measurements I developed are correct. In the drawing I posted, the instructions from Tatman provided the distance between the ribs, and from rib 1 to the transom and rib 9 to the stem. I worked out the side panel distances from chine edge to sheer line. Does anyone have old Greg Tatman plans that would confirm my measurements? hgunersut the rest.e and eobu
Re: Partial Don Hill Plans problem
September 06, 2017 10:46PM
You should probably try Wooden Boat People too. Someone there probably does have some old Don Hill plans.

http://westcoastwoodenboats.ning.com/
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