Building the Floats - Step 1

by Web FishFeb 21, 2013 @ 01:57pm

Bulting the floats: Part 1

After spending a good portion of the last month experimenting with various build techniques (composite skin with minimum glue-on frame, one-off float core cast from two-part polyurethane foam, even considering CNC machining of the foam cores) the decision was finally made to go with a structural cross-frame built of 1/8" plywood, polyurethane foam cast inside the frame cells and a fiberglass skin finish. This will give us almost 100% flotation preservation in the event of float breach (OK, it is probably less than 100% as the polyurethane foam will never be 100% closed cell and as such it will soak water in the event of a skin breach, but it's way better than a hollow float), manage-able cost and reasonably reproducible results (shape/weight) using simple tooling (we will need at least four of those floats). On the flip side, this is a bit more labor intensive than simple foam casting / machining, and the solid hulls mean that we'll have to fit the navionics bay and all batteries within the deck structure. Under other circumstances this would have been a less-than-desirable solution (high center of gravity) but considering our overall design (what is up today might actually be down tomorrow) this works ideally to contain the weight in a balanced way.

 

  • The float frame starts as 4 separate elements: upper deck, lower deck, upper keel, lower keel:

 

  • The upper deck with the upper keel section:

 

  • The lower deck attached to the upper keel section:

 

  • The lower keel section attached to the lower deck:

 

  • The extra cut outs (keeping the overall float frame structure under 18oz.):

 

  • The motor pod tunnel:

 

  • Finally, the deck frame mount points are bolted on / glued and float frame is ready for the foam treatment:

 

Laying Down The Keel(s)

by Web FishSep 26, 2012 @ 05:51pm

With the printed keel and rib templates and a sheet of plywood, time get make some saw-dust: