Foam dinghy

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fallguy1000
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Foam dinghy

Post by fallguy1000 » Wed May 20, 2020 9:02 pm

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So, my cousin wants a foam ultralight dinghy to replace a Walker Bay.

I have the TD3 plans

His Walker Bay is like 80 pounds and only 8 feet long.

And he has it on Davits.

I figure I can probably build something that will weigh in at 35 pounds max.

Does anyone know how I would rough in davit connections?

Is the td3 able to be shrunk to 8'? If so, how?

I would pay for a td2.5 plan if it were needed. But it also seems fairly easy to shrink a 10' plan to 8? Then because we are pushing the weight down hard; can I get away with anything on the scantlings and should we make it narrower?

Thanks in advance Jacques, for any reply. I might get started soon on this one. It would be the first foam boat and just a two seater.

I think he has a 2 hp Yamaha.


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fallguy1000
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Re: Foam dinghy

Post by fallguy1000 » Wed May 20, 2020 9:04 pm

Also, anyone have a picture of how davits are connected?
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fallguy1000
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Re: Foam dinghy

Post by fallguy1000 » Wed May 20, 2020 9:06 pm

I am also thinking about building it with 6 ounce glass on the inside. I have to look at the scantlings, but I was gonna bag the panels on the inside and then handlay the exterior with say 12 oz biax.
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fallguy1000
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Re: Foam dinghy

Post by fallguy1000 » Wed May 20, 2020 10:51 pm

Also, if we take the td3 down to 8 feet, this is a 20% reduction...what then should happen to the beam?
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jacquesmm
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Re: Foam dinghy

Post by jacquesmm » Thu May 21, 2020 9:59 am

I have drawings for a T3 scaled down and redesigned for 11' 5", made in foam sandwich, lightest version is 65 lbs.
It sits on my desk since Thomas (the original designer) disappeared at sea.
I may reactivated the project.
Image

BTW, that Walker Bay is nice but around 120 lbs.

Do you have a davit?
Jacques Mertens - Designer
http://bateau.com

fallguy1000
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Re: Foam dinghy

Post by fallguy1000 » Thu May 21, 2020 10:30 am

I want to build the dinghy at 8'; same like the WB.

It is for my cousin who is born 1941 and lives on Whidbey.

I want to build it ultralight.

I am a little torn on the method. I have read the method and understand it well, but I sort of like the idea of glassing the inside panels first. Then stitching and then less glass outside.

It is your design and I was hoping to bounce the idea off you.

Also, at 8' long; how to shrink it and how to adjust beam, or if...

Who disappeared at sea? Thomas?
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fallguy1000
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Re: Foam dinghy td3

Post by fallguy1000 » Mon May 25, 2020 4:50 pm

Jacques-I think the td3 is missing the spreader widths. I can sort of guess my way to them with a batten.

I am looking at laying this out today a bit.

Not sure if you can draw a td2.5 at 8' long, but it looks like the best way is to shrink all stations and modify the seating? It also looks tempting to just push the bow back, but a bit nervous about the leading edge in water then.

Also, be glad to pay you for the 8 footer.

I think your glass plan is also a bit heavy for an 8' version. Mostly the sides seem heavy to me.. For 12-15mm core, 6 oz glass is plenty; especially if you rubrail and inwhale. At least the insides could be 6 oz.

I might build it inside out. So flat layer inside 6 oz, glue up, radius edges, tape seams perhaps rebated seams, 12 oz biax outside. Flip. Tape seams. Add scratch pads under feet 6 oz.

I am also tempted to go as light as 6mm core on the sides with inwhale and rubrail to stiffen with HD core epoxied on. Only question is would it be easy to break resting on edge..that we don't want...but the force is all on the exterior 12 oz skin, so unlikley...

Let me know if you have any thoughts on the matter.

I think I will do a video or stills for you.

Appreciate especially on how to shrink it to 8'.
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