Lofting explained

[Keith P]

This question is kind of a off shoot of Scott T's post "Drawing Station Molds From Offsets? " http://forums.wcha.org/showthread.php?t=1246

What literature or training do you recommend to learn how to loft a canoe?? I have picked up Vaitses's book on lofting but I can't seem to relate it to a canoe. Maybe I am too dense..... I think if I had some kind of document that step by step showed how to loft a particular set of "Canoe Type" offsets than I would get it.

Any suggestions on helpful lofting education sources would be most welcome.

Thanks in advance.

Keith P.

PS:

I am in Colorado so it would be kind of hard to get to Maine to one of the Wooden boat School lofting classes.

 

[Todd Bradshaw]

Canoes are fairly straightforward to loft (at least you don't have to loft out complex parts like raked, curved transoms) so my suggestion would be a two-book approach mixed with practice in the form of an actual lofting exercise. I'd use your lofting book and also a copy of something like "Rushton and His Times In American Canoeing" which has tables of offsets and drawings for several canoe designs - so you'll have some offsets available for a boat that you can relate to.

Lofting is one of those hard to describe things that's actually easier to do than to explain. There is no substitute for just jumping in and starting so I'd pick a boat from the book, get a big hunk of paper and a couple long battens and try it. If you use the Rushton book, the drawings will give you a pretty good idea of what you're shooting for. Be aware that there are some errors in the offsets listed in that particular book (as there are on many boat plans) but one function of the process of lofting is to find and correct them, so fixing them is just part of the normal process.

If it's just for practice, you can loft at a reduced size, but you'll get a better feel for the process and working and fairing with battens on a project that's at least 5'-6' long. It's also possible to loft using a basic computer drawing program (that's what I use). It doesn't need to be a boat design program, but they're specifically tweaked to save you time. Real lofting on real paper probably teaches you more and is the logical place to start, but computer lofting allows you to print out the results and make poor man's half-models, which are kind of fun.

 

[Dan Miller]

One of the best descriptions of the lofting process are the articles by Greg Rossel entitled "Lofting Demystified" In WoodenBoat Issues 110 and 111. This article also appears as a chapter in his book "Building Small Boats" which is well worth getting a copy of.

For computer lofting, try the free boat design software FreeShip! from www.freeship.org. It's a very powerful program and the cost is just right. The learning curve for computer-aided boat design can be steep, so if you've never done it, it may be faster to just do it by hand.