The fastest way to build a scalemodel would be to cut pieces of 1 mm aluminum sheet with a scissor and tack it together with a mig or ac-tig. It should be easy to build a scalemodel in under half hour or soo.
Cheers
Johannes

Tom - 30 January 2014 04:17 PM

I’ll probably look for the glue sticks or Bondo.  Gap filling fillet joints are gonna be the order of the day.  Thanks guys.

I’d look at PVA glues like Titebond II or III. Some people use them to build small boats.
http://www.clcboats.com/forum/clcforum/thread/13346.html
It should be fine for a model.
I’ve made paste with Titebond and sawdust for filletting. It dries rough, but seals the joint.
Curtis

cpcanoesailor - 31 January 2014 08:09 AM

I’ve made paste with Titebond and sawdust for filletting. It dries rough, but seals the joint.
Curtis

Although I haven’t tried it, I recently read an article suggesting mixing together 100% silicone caulking with ordinary cornstarch. An array of runny/sticky to very stiff, clean-hands putty can be had, and it vastly shortens the setting period—to only a few minutes for the stiffest mixtures; 10-20 mins for the runniest.  Final set product is rubber-like with good adhesive qualities. http://www.instructables.com/id/How-To-Make-Your-Own-Sugru-Substitute/

Here’s a new version of the cutaway forefoot experiment.

Its as much toying around with aesthetics as anything.  It would be a simple, flat bottomed plywood dory with a cnced foam bottom/keel. 

side…

3q

Luomanen - 02 February 2014 01:54 PM

Here’s a new version of the cutaway forefoot experiment.

Its as much toying around with aesthetics as anything.  It would be a simple, flat bottomed plywood dory with a cnced foam bottom/keel. 

Nice! That dory would be asymetric, of course, right? If you could live with the sharp chines, I’d lobby for getting the keel out of a stack of hot-wired slices, then hand finish to get the organic shape into it.

Or then again, why not go with foam bottom (as we discussed the other evening) and then carve the whole thing? It’d be a thing of beauty, even though arguably nearly as much work as a foam-stripped hull. (The foamie’d be lighter, even fully fiberglassed, if my experience is typical)

Tell you what; re-think the shape so that, with a ~24” model we could get the sharp-chined dory out of 1/8” plywood or balsa plus 1-2 bulkhead/frames, glue a simpler shape keel to it, and let’s build/test 3 models—one asym only (like a T2), yours and a symmetric dory with a leeboard/offset daggerboard. Be no big deal to tow them at different speeds (as I think Mal mentioned); yielding a graph of Cl shift with, for instance, velocity. Could do the weight shift modification you suggested at the same time. This is the work of an afternoon or two, either in 2-4’ deep water or my swimming pool, and a couple of 10’ step ladders (one for the gravity powered tow, the other as the camera platform.)

Didn’t you mention you had kids? Kids need science projects, right?

Dave

The dory body is asymetric—1/3:2/3 beam at the center bulkhead.  Red is WAY more asymetric, with a straight keel (plan view) and just a little flare (7 deg) on the leeward side.

I get way ahead of myself when I start thinking about these experiements.  It feels like a lot of moving parts to understand the big questions I’m interested in.

1. Will a Marshallese style hull like Red go to windward effectively with a boomless gibbons rig?
2. Compared to what?  How well does a Brown style boat (mild V shape, rudder/daggers and ama dagger) go?  How about compared to the cutaway forefoot/speer section mini keel?
3. How big a role does the aero part play?  What are the most weatherly, simple proa rigs?
4. What do we want CLR migration from weight shift to look like?  Do we want large migrations for course stability and fine tunability?
5. What about boards in the ama?  I can imagine a flat or round bottomed vaka with two daggerboards in the ends of the ama that provide lots of clr migration. Two reels that raise and lower the boards would be used for steering. 
6. What about two boards in the vaka with reels?  The constant camber proa that Jim Brown made in micronesia had that kind of set up.  How did it work?
7.  Symetric v. Assymetric.  Does it matter once you have foils?  Does it ever matter?

Some of the Hydro questions can be answered with towing models—and maybe that’s where to start.  Establish a few hydro side models that feel good and then come up with the rigs that make sense for them.

Otherwise the list of questions just keeps growing, and with it all the combinations of hulls, rigs and foils that we might try.

AKA what Dave said.