Adirondack guide boats, the ultimate use of hand tools

[thomas prevost]

If any of you are vacationing in the Adirondacks or Vermont, a stop at the Adirondack Museum in Blue Mountian Lake is well worth the visit. The have a large collection of Adirondack guide boats and wooden canoes including construction demos with the old hand tools. These were built in the end of the last century and until the 30's. There are canoes that weight less than 20 lbs(13 lbs) that carried a man all over the lakes. The Guide boat is unique to the ADKS. It looks like a canoe but is rowable and will hold up to 4 people and gear. They typically are 18-20 ft. and weigh about 60-80 lbs. These were built with planes, chisels and slicks to tolerances in the 1/64 inch. Also unique, they were built by loggers and guides during their slow times.

My grandfather worked/studied under Lewis Grant, one of the last to make them using traditional techniques and tools. He showed me how the tools worked but unfortunately died before he taught me to "properly" use them.

[John Motzi]

Hi Thomas,

Blue Mountain Lake is one of our favorite places. I was mesmerized one rainy day last summer watching the videos of those old masters at work making the boats stick by stick with just a few hand tools.

[Bob Smalser]

...to tolerances in the 1/64 inch.

http://www.adirondack-guide-boat.com/agb_image_file/lewiscreek.jpg

Lovely little clench-nailed boats, but for woodworkers, let's clarify this.

Any time you run your finger over a joint to feel is one member is proud to the touch, you are building to 1/64th, because that's the limit of what you can feel. Small boat and canoe plans are to 1/8th tolerance like in the table of offsets for the hull shown below....and you can't show me a "perfect" boat that's not out of symmetry by up to an inch here and there.

http://pic3.picturetrail.com/VOL12/1104763/2595357/96672158.jpg

It's simply the nature of the beast when you bend wood around a mold....when one side doesn't bend perfect to the other side, it's called a "wow" in the planking. All wood boats have them...the only issue is whether you can see them or not. Make a part for one side of the boat and make its opposite as a duplicate without an entire separate set of measurements and you'll be surprised how unsymmetrical they are.

http://www.sawmillcreek.org/showthread.php?t=10383&highlight=3-board+door

[Michael Perata]

Any time you run your finger over a joint to feel is one member is proud to the touch, you are building to 1/64th, because that's the limit of what you can feel.

Bob

Sorry to disagree with you, but even a well calloused finger can feel an offset of a tenth (0.0001"), although anyone complaining about something being proud a 64th better have a fat checkbook.

I will agree that no one has ever built a perfectly symmetrical boat, even when it comes out of a plastic mould.

[John Keeling]

"Small boat and canoe plans are to 1/8th tolerance like in the table of offsets for the hull shown below....and you can't show me a "perfect" boat that's not out of symmetry by up to an inch here and there. " Originally posted by Bob Smalser


I hate to disagree with Bob and usually wouldn't but here we have a slight semantics issue. The 1/8th is the level of precision we are building to, ie the smallest measured division. The tolerance we are building to will be less than this. Of course when building a fully 3D object our 1/64th" measurement tolerance may have a bigger impact on the finished shape since each component has position as well as length and positional errors are additive...

1/64th"? My components may be measured to 1/64th" but there's definately about 1" of 'off symmetry' in my boat. Thought i'd done a really lousey job. I was glad to hear Bob say this is 'normal'. Bob, you made my day!

John, NY with a very nearly finished Merlin Rocket sailboat.


http://home.nycap.rr.com/thekeelings/MerlinRocket1.html

[Bob Smalser]

Ok, Ok....I'll defer to you fellas who can split hairs with precision and tolerance and feel .0001" with your fingers...

...but why would I want to?

In boatbuilding practice, your stock is milled to a 64th, your molds come out to around a 16th and the planks you bend around them are precise in direct proportion to the number of molds used. The Herreshoff System of one-mold-per-frame is the most precise....so a well-built Haven 12 with 16 or more molds will have smaller wows than a boat of similar size built with two molds.

The only issue is whether the casual eye can see them. In a piece of suqare and plumb furniture, you can see an imperfection of a 32nd or so. In the curved planking of a 20' boat, you'll never "see" an inch or slightly more without resorting to levels, plumb bobs and string lines.

Nice Merlin, John.

[Bob Smalser]

http://pic3.picturetrail.com/VOL12/1104763/7372002/96856011.jpg

Here's an example from this morning....fitting sternsheets and side seats in a professionally-built dory from the 1960's.

Look at the front seats...not the back ones as they aren't fitted yet. The lines are fair...the seats look like they match...the sides of the boat look like they match...

http://pic3.picturetrail.com/VOL12/1104763/7372002/96855998.jpg

...so you'd think if you bookmatched those two seats, they'd be pretty close....not exact by any means, but pretty close, eh...say, within a quarter to a half inch?

http://pic3.picturetrail.com/VOL12/1104763/7372002/96856024.jpg

If you thought that...you'd be wrong.

[thomas prevost]

I think perhaps we are talking apples and oranges here.

It may be my fault as I am not sure of the right terminology. Each guide boat is built individually and is not an exact match to any previous one, either length or width. But the fitting tolearances for each boat are very close to make it water tight. The planking for the boats is quatersawn white cedar or white pine 3/16" THICK. It is shiplapped at 13 degrees with a 1/32" resulting edge on each side. How far off can one be such that they will not seat together properly? An 1/8 inch is 2/3 the thickness of the planking. Similar with scarfing. much more than 1/32" and 3 inches in board length is lost and no fit will occur. To complicate things all of the planking is egg shaped to fit the sharp widening of the boat from stern to center(length) , not straight boards.
The ribs are 1/2" half round from hemlock root following the natural curve. again, 1/8" would be a variation of 25% in size for each.

I was not talking about 1/64" in lenght, width and depth from boat to boat.
Sorry for the confusion.

[Bob Smalser]

I'm not picking on you, Thomas....I just like to talk boats.

Your plank laps are much tighter than 1/64th...they touch snugly.

[Steve Cox]

Interesting discussion. Thomas, you will find on almost all boats that the planks are egg-shaped or some other shape, or even have an s-curve in them when looked at off the boat. The process of making them that way is called splining and is very basic to the boatbuilders art. When comparing cabinetmaking and boatbuilding (I have a formal education in both) it is always very interesting to me that cabinetmaking is all about precision by measuring and leveling and making everything precise to a set distance (30" +/- 1/64" for example) whereas boatbuilding is all about the same precision of fitting but much less about the measured precision (witness Bob's example above). Bob, you hit upon the two most descriptive words between the two trades. Cabinetmakers want to know if it is square. Boatbuilders want to know if it is fair.;)