Thursday, February 23, 2012

Lofting

Lofting began in March 2011. Just in case you are new to boat building-- lofting is where the builder takes the "lines plan" from her blue prints and draws it out life-size. This way, the builder can be sure that the sheer and the chine are fair (not lumpy). It is then possible to take more accurate measurements from this big drawing.

I approached the lofting step with a bit of apprehension- it seemed that it was something that people were afraid of, as evidenced by boat designers advertising, "NO LOFTING NEEDED! Full size patterns included!" I figured that if those designers were selling full-sized patterns, then there must be some sort of demand for them from boat building folk. I also figured that all boat building folk are more experienced than I am. It then follows that if those people preferred full size patterns, what was I doing thinking I could loft-- much less build a boat?
But I tried anyway. I ordered some Tyvek housewrap on eBay to use as my lofting paper. The more traditional approach is to draw the boat directly on the floor, or use builder's paper-- but the Tyvek ended up working out really well. The morning dew didn't do any damage, and the sand that inevitably gets into everything here (even my bed) didn't grind its surface away. Plus, I'll be able to re-use this tough stuff later to make ultra-light duffel bags and a sail for the dinghy. 

Maybe I could even plate the hull with it like this guy.


In any case, the process ended up being really simple:
1. Draw a bunch of straight lines.
2. Draw five curved lines and make sure they aren't lumpy.
3. Measure everything.


The only materials I really needed were an 8 x 32 ft. piece of Tyvek, duct tape, a long piece of pine trim from Home Depot to use as a batten, several different colors of marking pens, a tape measure, some 8D nails, some 1/4" staples to staple the Tyvek to the lofting floor, and a straight edge (ripped from a piece of 1/4" 4 x 8 ply).

I was about halfway done when I came to the shop one afternoon to find that a little over a quarter of my lofting had been eaten. I found the culprits in the mechanic's garage next door, but they were just too cute to scold. I cut out the chewed-up parts, made a big patch out of builder's paper, fortified the lofting floor, and finished up a few days later.


The puppy perps



I made patterns of the keel pieces using strips of quarter inch ply and staples. This made the chunks of keel easy to cut out accurately later. Note the jugs of water-- Mrs. Alvarez took pity on me when the dogs ate my lofting and brought me the jugs saying it would keep the dogs away. I'm not too superstitious, but it was a nice gesture.


Ramon measuring angles to use later in beveling the frames.


Honestly, it was pretty easy. Granted, I won't know if I did it right until the frames are up, but hopefully my sheer and chine don't look hilly.

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