Folding Beach Cat

[jtremolo]

I am working on a design for a folding beach catamaran for lake/bay use. The Hull Design is almost done, but I have a couple questions. 1)If I post my design would someone be willing to take a quick look and see if the hull shape/size is reasonable? 2)I am planning on constructing it using the stich and glue method. Do i need to glass/epoxy the inside of the hulls since the will be completely closed? i.e they are hollow but have no holes/access openings etc. to leak

Thanks,
Jordan

[champ0815]

I think it is a bit risky to seal your hulls completely. In case of ground contact (not unusual to a beach cat) small leakages can occur and you are better off detecting them with some kind of access to the interior of your hull. Therefore a coating on the inside would be advisable too, since in case that water finds the way inside, it can be removed without causing further damage to the wood...

[jtremolo]

That was one of my thoughts, I just wasn't sure if it would be a huge problem since it is a beach cat. I was just looking to save weight/time/money if possible. Thanks for your input.

[uncookedlentil]

your layup can gain a lot of strength by fiber glassing both sides of your plywood besides the waterproofing advantage.

remember, water, like rust, never sleeps

Roderick McAlpine Downey, may his great designs be ever remembered, did a folding beach cat, back in the sixties, called the Shark that still has a small but devoted following.

His hinging was fairly simple and very strong, no failures except some fairly spectacular ones on old dry rotted boats.

[jtremolo]

Have you ever seen any small boats use the concept in the attached picture? I was contemplating buildng a small scale model for testing, I also created a CAD simulation as proof of concept, with the proper hinge/lock mechanisms it is actually quite stable and very rigid.

[Zilver]

Originally Posted by jtremolo

Have you ever seen any small boats use the concept in the attached picture? I was contemplating buildng a small scale model for testing, I also created a CAD simulation as proof of concept, with the proper hinge/lock mechanisms it is actually quite stable and very rigid.

That looks geeky (is that English) !
I wonder how you transport this boat when folded. Or is it meant to take little space in for instance a boathouse ?

Cheers, hans

[jtremolo]

well, it could be transported in the bed of a shortbed truck like my ranger, or on the top of a small car. I suppose you could pack it for storage in a boathouse too. Yes, it's english

[TTS]

Let's deal with the first question as to glassing the inside of the hull. I built my tornado with what you call stitch and glue and I call tortured plywood construction. You use the plywood as a structural core and the glass and epoxy as inner and outer skins of the laminates. The wood core gives you a great deal of strength alone, but the glass skins give additional and needed support to the core. As to the design, there is someone in England or Europe who is building something that is very similar. I do not know if I ran into this design on this site on another thread or somewhere else.

[jtremolo]

The animation i posted was off of a different website, but it said it was a concept. I was just curious if anyone had tried to build it.