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Old 10-13-2015, 07:12 PM   #21
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Originally Posted by Xsbank View Post
Curious as to how this differs materially with a fiberglass boat that is wood cored? Seems to me the largest difference is in the use of pigmented fiberglass or a shiny gelcoat on the wood-cored example. You still need to keep the water out and be prepared to repair any incursions quickly. Cold-molded/composite boats, until Huckins etc were mentioned, I had always assumed were hand-made.
The structure of the boat is wood. The fiberglass is thin, covers the exterior of the boat, needs to be faired and is not really structural but does help provide some bump resistance. The epoxy used to treat the wood should prevent worms from getting into the wood and certainly the fiberglass should. One does not need the fiberglass per Dix.

Later,
Dan
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Old 10-13-2015, 09:30 PM   #22
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Eric,
Yes, I glassed the outside with too many layers by today's standards. The interior of the hull was saturated with cuprinol preservative. When I saw the boat last there was zero rot due to the cuprinol. Resorcinol glue was used and thousands of screws driven with brace and bit. The engine was a single tower of power, I believe 70hp. It was made with the finest mahogany plywood that I have seen. Ken
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Old 10-14-2015, 06:38 AM   #23
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"Resorcinol glue was used and thousands of screws driven with brace and bit."

More common in that era was Monel staples that could be driven quicker to mthin the glue line.

The monel staples were left in place in each layer.

On a large order one could request the ply used for the hull to not be factory finish sanded , saving time in assembly.
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Old 10-14-2015, 10:43 AM   #24
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"Resorcinol glue was used and thousands of screws driven with brace and bit."

More common in that era was Monel staples that could be driven quicker to mthin the glue line.

The monel staples were left in place in each layer.

On a large order one could request the ply used for the hull to not be factory finish sanded , saving time in assembly.
I believe the kit supplied silicon bronze screws, so that is what we used. I have built other boats using "boat nails" and glue. Overall, building boats was good for me in my teenage years. It also got me onto the water in a wild and beautiful area. The last boat I built for a friend in 2007. Getting a little old for building but would love to build one more.
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Old 10-14-2015, 11:12 AM   #25
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Chriscraft kits were Philippine mahogany plywood and frames. There were a number of production small boats including canoes that were cold molded mostly from the midwest. Yellow Jacket , and Dumphy come to mind. The advantage of cold molding is diagonal strips being penetrated with epoxy and every 1/8 inch or so. Dry rot is still possible but greatly diminished. Also by using narrow strips the wood cells are isolated in each strip by an epoxy barrier between the strips. I'm not a fan of using plywood strip because the wood has already been stressed when it it turned off the log and flattened. The checking you see in plywood siding is caused by this. It's more expensive but stronger to use wood strips. Cold molded red cedar which has natural rot resistance would be a good choice.
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Old 10-14-2015, 01:42 PM   #26
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After a camping/fishing trip to the Yukon years ago I decided I wanted to build a 20' freighter canoe. The following year I visited a canoe builder in Maine who advertised in Woodenboat magazine in those days and who used the cedar strip/West epoxy method of construction. He explained the process he used and showed me some of his completed boats. It was beautiful work.

In the end I opted for traditional wood and canvas construction but the cedar strip/epoxy process would most likely have been faster and easier and yielded a tougher boat.
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Old 10-14-2015, 02:27 PM   #27
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Cold-Molding refers to a construction method where hull planking consists of multiple layers of wood laminated together using epoxy. Whether the wood is solid timber, veneer, or plywood makes no difference. Composite construction refers to "strongly bonded dissimilar materials". In modern boatbuilding, composite construction refers to a foam core with mixed skins of carbon, kevlar, and various fiberglass reinforcements. The boat in the original post is built using cold-molded construction methods, and is sheathed with fiberglass. The reference to composite is a dodge, so the broker doesn't have to mention the dreaded "W" word. It's arguable how much strength the fiberglass adds to the structure, but it's not a lot. Mostly it will add abrasion resistance and some puncture resistance.

The picture shows a section of Scheherazade's cold-molded hull sitting here in my office. She's the 154' ketch built by Hodgdon's and posted above by TDunn. I'm one of her designers. As you can see the hull is built of 7 layers, and its close to 3.5" thick in total. The inner layer is vee-jointed tongue and groove fir, 3/4" thick with the grain running fore and aft. In the middle are four diagonal layers of 3/8" red cedar. In high-load areas (keel bolts, chain plates, rigging, etc.) mahogany is substituted for the RC. The outer layer of planking is another 3/4" douglas fir running fore and aft. Finally a sheathing of fiberglass, in this case pretty heavy biax or triaxial almost 1/16th thick. Towards the bottom of the block you can see one of the plastic nails used between layers to hold them in place while the epoxy sets.

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Old 10-14-2015, 03:35 PM   #28
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When we were living down in New Zealand I looked at a number of the locally produced cold molded hull sailboats. They were laid up using multiple layers of Kauri wood, epoxied together diagonally and stapled to hold the layers together until the epoxy had set, the black plastic staples were then sanded off leaving a bunch of little black spots that looked like fly specs.. I thought it was a great way to lay up the hulls.

They were perfectly fair and painted on the exterior and typically finished clear on the interiors. the hulls were light and fast.. and beautiful. I would rather have one than a cored F/G hull any day. They were also warm and quiet like only wood can feel. Maintained right they will last as long as anything else. I believe the Schooner Creek boats built by Steve Rander were of somewhat similar construction.

A cold molded hull isn't a "wood boat" that should be feared like a planked hull.
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