Half Hull for CD30K

[grluecke]

Well, my son has had the opportunity to sail for several months with an older, well-off guy on his Concordia 39. "Crew", not so much after he turned 80, closer to "Captain". With ocean crossings, scrimshaw, and knots & weaves, he has pretty much eclipsed the skills I taut him on the Hobie, Prindle Cat and Thistle as he grew up. It's hard to argue with him when I know his skill level...

(see the post on the Cape Dory section on "anchor windlass" for more insight...)

He thinks we should have a half-hull in the saloon, and since he is land-locked in Michigan, over last weekend, LOOK WHAT HE DID!

Down to Lowes, he found some thinnish premium boards, Red Oak and Poplar, cut the loft lines and laminated them together: see the first file download. Sorry, just learning the system...

Ok, then, now we need to make heavy use of the Dremel Tool in order to fair out all the slabs.see Rough1, below...

My son whittled a rudder, put it on, and sanded it smooth...

Then I compared it with a real hull.

With a lot of sanding, he got everything really close. But his shear line still needed to be cut. Check out the loft lines in the background.

Finally, his model did not look right, so I found a pic of a CD30.

[Steve Laume]

I made 7 half models of the CD-30 last winter. I got the plans from from Todd Dunn. They appear to be the same ones you used. The problem was that he did not include water lines in a plan view. I spent a bunch of time drawing them up from the other two views. This gave me accurate lines to cut the lifts. Gluing them up while keeping everything aligned was the hardest part of the project once I had all the lines.

Working with alternating lifts of hard and soft woods does not make the project easier. I laid up the first one with a butternut bottom, a 1/8" walnut boot stripe and maple top sides. The maple was a bear to shape so I switched to white pine for the rest of them. The hull at the top of the rudder is not exactly right and I think it might be a flaw in the plans but it is still pretty close.

Since I knew I was going to be making a multitude of these I make up some templates and jigs. The most helpful was a very accurate cut out of the elevation view on 1/2" birch plywood. If you cut that out and smooth the edges, you can screw it to the back of the half hull once it is glued up. Once this was done, I put a 1/2" flush cutting router bit with the bearing on the bottom in the router table. It was then a simple matter of following the pattern to get the outline of the hull in elevation. I didn't have a long enough bit to cut the entire deck to shape so I chucked up another bit with the bearing on the bottom in the drill press to finish it off. This could have been done by hand but was easier in the drill press but be careful.

I had a chance to try various shaping tools and found the the best and fastest was a very sharp chisel followed by files and sand paper.

When the models were completed I gave each one a coat of West epoxy with the special clear hardener. This gives you one last chance to sand and smooth before applying finish. It also builds up a good base so you don't need to many coats of varnish.

Your model is looking good. That area around the stern was the hardest to get right and some parts get a bit thin. The 1/2" birch helped back up the parts that could have been damaged by shaping. I also screwed a wood block to the back of the pattern so I could clamp it in a vise. In all I think that backing template made the job a whole lot easier. If you don't have a router table you could probably clamp the router in a vise and still follow the pattern. It will straighten your shear line right out for you.

Your son is right, we should all have a half hull model in the main saloon, Steve.