Adapting old plans

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bklake
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Adapting old plans

Post by bklake »

I guess this belongs in this category. I have HB16 plans. The size and hull are perfect but I really don't want or need the house part. I was panning to eliminate the cabin and flatten the sole. I want a slow, shallow draft boat with a ramp that can nose up to beaches and sand bars. I found a plan called the PM's Platform Boat from March 1966. https://www.svensons.com/boat/?p=HouseB ... atformBoat There is a Google book version that is clearer. This boat is almost everything I was looking for. It seems to be very thrifty is wood usage.

To my hobbyist, untrained eye, it could easily be adapted to modern stitch and glue. I read the Boatbuilder pdf about adapting old plans to modern techniques. Almost everything on this translate very well. It is almost stitch and glue before stich and glue was a thing. Anybody have experience with adapting old plans?

fallguy1000
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Re: Adapting old plans

Post by fallguy1000 »

I would say I could probably help, but only as a friendly gesture. Not gonna take on any liability.
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viewtopic.php?f=12&t=62495

fallguy1000
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Re: Adapting old plans

Post by fallguy1000 »

Start by writing a statement of requirements...all the wants and needs of the boat. Width, length, horsepower, planned use; everything possible.
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bklake
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Re: Adapting old plans

Post by bklake »

I have some homework to do but here is a start.

Basically the size of the boat in the plans. 8 foot beam and 16 foot length. Flat deck. Probably 9.9hp motor so my kids can operate it. Mostly flat water but has to handle wake from passing boats. It seems there are a lot of new boaters in my area and No Wake doesn't mean what it used to.

The plywood thickness specified in the Platform Boat plan is very similar to the HB16. The frame spacing on the HB16 is about the same as the bulkhead spacing. There are no stringers in this like the HB16 but the Platform is a pontoon boat basically. Between the plans I have, the adapting old plans guide on boatbuildercentral and some help here, this might be possible.

Every sentence of the PM article is an in depth instruction. I read the whole issue and it seems like everyone in that era had a small machine shop in their garage and the basic skills to operate it.

TomW1
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Re: Adapting old plans

Post by TomW1 »

bk if you read the introduction to the HB16 this boat was not designed by Jacques, but by Emile Ajar based on the 1960's house boats from the DIY magazines. I remember(showing my age), my dad got the magazines. I think you have a great idea to build it without the cabin. Good luck and post pictures as you build this.

Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

bklake
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Re: Adapting old plans

Post by bklake »

I think I will try to find the old house boat plans that the HB16 were based on. Then, compare them to my HB16 plans to see what changes were made. I should be able to figure out a direction to go.

fallguy1000
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Re: Adapting old plans

Post by fallguy1000 »

Is there offsets or lines in the article?

Kinda small to read on iphone.
My boat build is here -------->

viewtopic.php?f=12&t=62495

bklake
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Re: Adapting old plans

Post by bklake »

No real offsets or lofting information. The radius of the bow curve is listed as 4'6". The rest of the boat is standard dimensional lumber or ripped from dimensional lumber. Each sentence in the article has vital instructions and or dimensions in it. There is some rocker in the hull. I can't find exact dimensions for the transom which would define how much rocker. Why would they provide a detailed radius for the bow and no other detailed numbers? I'm going through it sentence by sentence to see if I divine this number. There is a nesting diagram and a materials list. I guess 3'x16' plywood sheets were available then(sarcasm). The text says you will probably have to special order it. If not available you will have to use butt jointed 8' ply and adjust the bulkhead at the butt joint. Details like this are probably slow down an experience boat builder about 2 minutes. The HB16 plans have all of these things accounted for. In the modern era, 4x8 ply is what you can get and everything in the HB16 is designed around that.

It's kind of fun going through this article and comparing my plans on hand. I don't think stitch and glue will save any weight but I'm pretty sure fiberglassed seams will be a lot stronger and more water tight than a row of ring shank nails sealed with mastic.

I'm sure the pontoon hulls on the PC series here are far more efficient. Those plans start at 20 feet and I really can't go over 16 feet.

jbo_c
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Re: Adapting old plans

Post by jbo_c »

Jacques has an article here somewhere about adapting old plans of this sort.

Jbo

fallguy1000
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Re: Adapting old plans

Post by fallguy1000 »

You would do a scarfing joint to make long panels. Bulkheads do not belong on joins. Bulkhead actually belong away from joins.
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