Building the Ellipticat

An experimental gaff-rigged catboat by Norm Bernstein

"Remember that a lone amateur built the Ark; a large group of professionals built the Titanic."  

(Dave Barry)

Email: norm dot bernstein at marisystems dot com (sorry, I'm trying to avoid the spammers from harvesting my email address)

LATEST UPDATE: Back to the rudder (1/6/07)   

NEW FEATURE: The Project Overview

It all started with my desire to build a boat. Here's why. You might also be wondering why I'm maintaining this website.


Actually, I've built a couple of 'tack and tape' small boats from the Phil Bolger / Harold Payson collection, but wanted to try something a bit more ambitious. My ideal boat simply had to be a gaff rigged catboat, very traditional looking, with outside dimensions of no greater than 15' x 6'6" (the limits of what I figured I could build and fit in my garage).


Since I'm a rank amateur wood butcher, and NOT an accomplished craftsman, it was clear that whatever boat I was going to build would have to be reasonably simple... and, being something of a New England skinflint, I also wanted it to be relatively cheap.


Unfortunately, I couldn't find any plans that met my specific desires... so I decided to get brave, and try an idea of my own. Starting with a commercial double-chined 'tack and tape' plywood design, I thought that I could convert to a round bottom by drawing an ellipse for each frame that matched the breadth and height of the original design.


So, I used my PC to create a set of 1/8 scale templates of my idea, and built a model (by gluing the templates to some foam core board, and cutting out the frames with an Xacto knife) that proved that the idea would work!


So, I developed my plan. The Ellipticat would be constructed with 3/4" x 4" frames sawn directly from plywood, strip-planked with cedar, and heavily glassed outside and inside. The boat would feature a partial deck with a traditional curved coaming, and a mast and spars laminated from fir. The boat would use a deep weighted centerboard and kick-up transom hung rudder, for simplicity of construction.


To keep things relatively cheap, I also decided to use common lumber from the local Home Depot or Lowe's. I have enough small boatbuilding experience to know that common lumber, when properly encapsulated in epoxy and fiberglass, is fine for small boatbuilding. This decision was easy, when I compared the price of a 4 x 8 sheet of 3/4" okume plywood ($160 or so) with the $30 cost of a sheet of 6 ply AC exterior ply from the home center. Sure, the okume is gorgeous stuff, with perfect faces and no voids... but at 5 times the price, just not worth it, especially for an experimental boat.
 

From experience, I know that there are a myriad of materials at the local home centers that work well for small boat building. For example, clear Douglass fir porch flooring, with a 1" x 4" cross section, is available in long lengths and is reasonably cheap. It is also very strong and nearly perfect in terms of clarity (no knots, etc.) I'll use it for the keel plank, the inwales, deckbeams, and the spars (laminated, of course). For higher quality wood, there's a local fine hardwoods dealer (Downs & Reader) who can supply white oak, ash, mahogany, etc.

It's going to look a little like this, when it's done... I hope!

My pitiful workshop. It's just a garage, 11' x 22', shared with the usual homeowner accoutrements like garbage cans, rakes, etc. Obviously, my boatbuilding is constrained to small boats! The only stationary tools are an inexpensive 10" table saw and a drill press. I've got the usual hand power tools: a jigsaw, circular saw, various drills, electric planer, several orbital sanders, etc.

 

Forget lofting, battens, etc. Drawing an ellipse is super-easy, all you need is two nails, a string, and a pencil. The 'string' I used was braided fishing line, which has very little stretch.

catboats as art

This one is by Winslow Homer, famous artist who often drew and painted traditional boats

 

next page

 

Page log:

Home page

Construction starts

Setting up

Scarfing the keel plank

Building the centerboard

Building the skeg

The planking arrives

Planking begins

Fixing some mistakes

Glassing the hull

Attaching the skeg

Turning the hull over

Inwales and Interior Fiberglass

Centerboard case

The Project Resumes... Floorboards

Mast Partner and Deckbeams

Taking a break... the tiller

Deck Framing Continued

Fixing Another Mistake

Decking over

Decking over, Part II: Teak

The gunwales and coaming

Caulking the deck seams

Details, details

Construction resumes

Back to the rudder

 

 

 

 

Cost Summary

 

Essays:

The Moaning Chair

Why build a boat?

Why this website?

Using epoxy in cold conditions

Errors, bad judgments, and lessons learned

Useful Tools