Thursday, August 28, 2008


I had someone comment on the picture below because of safety concerns:

Let me elaborate a bit - the table saw's insert has been deliberately removed. (the big opening with the spinning saw blade is the area we're talking about) By no means is this a standard procedure. You should use the equipment's safety attachments and follow the manufacturer's instructions about proper use of the equipement you are handling.

In this operation, the sliding jig that is clamped to the saw table is being used to cut tapers on the ribs and the by-product of this cut is some long (10") wedge shaped pieces (~3/8" at the thick end) With the table saw's standard insert in place, these wedges get caught very easily and are thrown back at the operator - a big hazard. Without the plate in place, these pieces of scrap simply fall into the saw. This was done at the recommendation of the instructor based on his extensive experience with this process.

In terms of operator safety, you are well away from the blade. The operator's hand sits on the table in front of the opening to guide the ribs and the other hand holds the ribs well back from the table feeding them.

In the future, I'd like to try that operation with a sliding jig that has the handle placed a bit further back so that you are not reaching past the blade when you have to re-set the sliding jig. Also, I'd like to see if a zero-clearance insert would help or hurt the jamming and kick-back of those little wedges. Still, I think I'd want a full face shield, kevlar apron or maybe some armor.

Safety first.


Hot Tubbing Failures in Maine :

Wednesday, August 27, 2008

Building a Cedar and Canvas Canoe : Saturday

On Saturday morning, our task was to fit out the boat with the trim that we manufactured earlier in the week. This included the grab handles, thwarts, yoke, seats and the outwale.

In the picture below, you can see the grab handles, thwarts and yoke. The handles, thwarts, yoke and rail were all cut from mahogany. The thwarts, yoke and grab handles have tapers on the ends to mate up with the inwale and are first radiused using a router and then made oval in cross-section using spokeshaves.

The decks were cherry (as were the seats - brought pre-manufactured and finished) and were cut from a steam-bent blank of cherry. The bend matches the sheer. We shaped and tapered the decks to fit between the spruce inwale and once the deck was installed, we rounded it over. The back of the deck is also thinned to make the boat a bit more elegant. I'll see if I can find a picture of that as we back up.

On the floor to the right of the canoe are the outwales still in the jig after steam bending. (they have the clamps on) These were cut and beveled to go over the planking and canvas and then soaked overnight in the pond behind the shop. Let's just say they had some interesting color and new occupants when picked out of the pond for steaming. In this picture you can see that there are temporary thwarts and handles installed to keep the canoe's shape while we plank and canvas the canoe. These are used to keep from damaging the finish trim.

Here is the canoe with the outwales installed and screwed in place. They've been tapered at the ends to reduce their width and would be sanded with a belt sander to enhance the taper a bit later.

Here are the finished products from the class - all beautiful work, indeed.

On the left is an Atkinson Traveler (17') , in the middle is the Model 1889 (16') and on the right is the Sojourner (13')

Building a Cedar and Canvas Canoe : Friday

Friday was a very big day in terms of work. The major woodwork for the hulls was complete. This is what we started the day with:

The line of blue tape was holding a chip that we'd glued back into the rib. It had split out when we were doing some clenching the day before.

The hull was grossly fair and straight, but required some minor fairing to get rid of some lumps and puckers in the bow and stern quarters at the turn of the bilge. This was accomplished with a good size disk grinder and a smaller palm sander to follow up. At this point, the ends of the planking at the stems was made flush and tapered a bit to make the ends a bit finer.

After this operation was complete, the outside of the hull was given a light coating of boiled linseed oil and turpentine to help to make this part of the hull a bit waterproof. It is also used to help inhibit the growth of mold and mildew on the planking. We thought the hull looked nice at this point.

After the hull was prepared, we folded a length of canvas in half lengthwise and used large wooden clamps to hold the ends, one end of which was attached to a large post wedged between the floor and the top beam of the canvas stretching assembly. The other end was attached to a fixture that was in the window opening and had a come-along which is used to tension the canvas. The inside of the boat is protected with cardboard and props wedged between the ceiling and the boat are used to push the boat down into the canvas.

Here's Jerry checking on the props used to force the boat down. One of the clamps is in the foreground on the right. This method was a departure for me. I'm used to stretching canvas outside between two trees and using bags of sand and other heavy objects to push the boat into the canvas. There are many ways to skin that cat.

Big "clothespins" are used at both ends to bring the canvas together at the stems. The canvas is then stretched up using special pliers commonly used for other tasks (Artist's canvas stretching pliers and welding Vise-Grips) The canvas is then tacked into the ribs and inwale just below the edge of the planking. Here is a picture of that task (Not our boat, but still the same class.)

You can just see the desired puckers that appear in the canvas if you've got good tension.

After all the tacking at the gunnel line is complete, the canvas was cut and the boat taken down. Here's our boat on sawhorses with the "clothespins" still in place.

At this point, the canvas hasn't been wrapped around the stems yet. A layer of bedding compound is put on the stems and the canvas is cut from the point at which it makes good contact with the stem and out away from the boat along the centerline. The first side is then drawn off across the stem and tacked every 3/4" or so with short tacks. This gets rid of any wrinkles along the sides of the boat in the front quarters. The leftover canvas is trimmed up against the stem. Another layer of bedding compound is applied and the process repeated for the other side. What you are left with looks like this:

You can just see a bit of bedding compound at the edge of the cut.

Before you can fill the canvas (No, I'm not giving away the formula for the filler! Old Timers guarded these trade secrets carefully...) you have to get rid of the nap (AKA : fuzz) on the canvas. this is done like this:

Yes, that is a propane torch we're running over the surface of the canvas on a nearly finished canoe. You can see the burn marks from previous passes. You need to be very careful and work fairly quickly avoiding any hanging threads or frayed edges.

I didn't get any pictures of applying the filler, but suffice it to say, it is mostly like painting the boat with rollers. If you look at my post from Saturday you can see the smooth slate gray finish. This is achieved by taking a canvas "mitten" and rubbing the surface of the hull after the filler is applied with the roller to smooth the surface and "kill" the weave of the cloth. It's not difficult, but takes quite a bit of energy. I also scorch the surface of my mittens to avoid getting lots of fuzz in the finish.

The other important thing to note is that we didn't paint or varnish the hull because the filler needs to cure. The filler contains oils that need to polymerize over a long period of time (4-6 weeks or even longer, depending on conditions) to be properly cured. After the hull is cured, 5 coats of varnish will be applied to the interior and 5 coats of good enamel paint applied to the exterior. Stem bands and (if desired) a keel are installed after this finishing.

Building a Cedar and Canvas Canoe : Thursday

The first thing that happend on Thursday morning was that we removed the canoe from the forms. This is done before the ends are closed up so that you can actually remove the canoe from the forms. I was a bit apprehensive about this step, but it was really pretty easy. The wires on the stems are released, you push gently down on the hull and voila, the inwales spread away from the mold under the tension from the ribs.

Temporary braces are seen in place to keep the canoe from spreading fully open.

The stems are then dovetailed by hand to receive the inwales:

The deck is then notched to fit over the top of the stem:

The deck's location is marked on the inwale and the stem is pulled up to an appropriate location. This is done by feel - you don't want to put too much strain on the stem by pulling it up too hard. At this point, the deck is mounted with some bronze screws to one of the inwales:

At this point, a highly technical piece of hardware is used. It's called the "standy-uppy" :

The "standy-uppy" is screwed to the floor and is simply there to help hold the canoe in position while the level is placed on the thwart. This is critical to getting a canoe that is straight. Once this is in place, the deck and stem are slid back and forth until the stems are plumb. Once this adjustment is made, the deck is screwed to the other inwale to keep it in place:

Once the deck is installed, it was time to shape and steam the cant ribs. Cant ribs are not like any of the other ribs in that they don't bend over the top of the boat. They are shaped to slide into position alongside the stem in the bow and stern of the canoe. These are cut from standard ribs that are left over from the steaming process. They are shaped by hand when hot and then clenched in place:

The top of the cant rib is then notched to fit up agains the deck. Sometimes these are thinned as well.

After the top of the cant rib is shaped, they are nailed to the inwale using bronze ring shank nails. The end of the stems and the deck have a screw installed to keep them together as well.

Now that all of the ribs and decks are in place, it is time to install the temporary thwarts by screwing them in place. The temporary thwarts were simply rough copies of the finished parts in terms of lenght and angle. Once these were in place, the last of the planking was installed. (WHISKEY PLANK!)

Once the last of this planking is installed, it is time to mark it and trim it. Here is the marking gage in action. It makes a line just above the bottom of the inwale so that when the canvas is cut flush, the outwale will cover the edge of the canvas and wood.

The planking is then cut down to the line using a utility knife to score and then cut. This planking is only 5/32" thick, so it isn't much work.

Once the planking is cut down, it is time to make certain that all of the tacks have been properly clenched and that there are no missing tacks. While in most areas, the steel bands did a good job of clenching the tacks, in some areas they aren't clenched at all. You simply get in the boat using a clenching iron (seen in top photo in this post) and back up the tacks on the inside of the rib. Then you give a good sharp rap with a hammer on the tacks on the outside. It is at this point that you realize that there are literally thousands of brass tacks used to build one of these canoes.


After all of the tacks have been set, the last step for the day is to take a swab and some boiling water and wipe down the whole hull to get rid of any "hammer blossoms"

After we completed this task, we retreived our mahogany outwales that had been soaking in the pond and steam bent them over the forms seen in Friday's post. After that we called it a day.

Building a Cedar and Canvas Canoe : Wednesday

Wednesday was all about planking. No doubt about it.

The first planks to go on are the garboard planks. To get them to conform to the contour of the ribs, a swab and hot water are used to make them flexible. At this point, the planks are about 3" wide and 5/32" thick and are from Northern White Cedar. Ideally, the planks are full length, but in this case the longest we had were about 10'. We selected planking carefully to put the knots behind the ribs. Where the planking was joined, it was cut at a bevel and the beveled joint was hidden behind the ribs. At the ends of a plank, small holes were drilled into the planking, but not the ribs. This was for the tacks so that the ends of the planking would not split. Brass tacks were driven through the planking and the ribs and clenched on the steel bands covering the forms. At the ends of the garboard, we drilled into the stem and drove bronze ring shank nails. At this time, only the garboard is attached to the stem.

Pay particular attention to the orientation of the tacks. They run diagonally to make the planking lay down on the ribs properly. In this image, the second plank is already in place on both sides and the plank ends are trimmed back to the stem.

More planking - note the wet areas and that the ends of the planks are neither trimmed nor tacked at the stem.

There comes a point at which it is necessary to 'gore' the planking. Basically, this is where the ends of the planks are tapered to get the planking to fit on the hull. The goring pattern for the planks can vary from hull to hull (i.e. which rib you start at, the number of goring planks, how far up from the garboard, etc.) and is somewhat of an art. On our canoe, there were three gored planks that were full width amidships and tapered out to the width of one plank in the quarter ends. In the picture below, you can see the third plank being prepared for goring. There are pencil marks that have been made using the metal underscribe gage that is on the sawhorse. After the lines are marked, they are roughly trimmed using a utility knife and finish fit using a plane.

Here is a picture of the finished goring and the plank that meets it at the end quarter. The diagonal tack pattern is very apparent here:

The ragged edge of the bottom plank would be taken care of once the hull was off the mold on the following day.

This is where we ended the planking process for Wednesday. After this was finished, we went and cut Mahogany for the outwales of the canoes.

It was both fun and very satisfying to see the work progressing so quickly.

Tuesday, August 26, 2008

Building a Cedar and Canvas Canoe : Tuesday

Tuesday was devoted to the bending of the ribs and the creation of most of the hardwood trim. The kit of ribs which were marked with their length, centerline and two marks 3/4" to either side of the rib's center were hosed down so they wouldn't dry out in the steam box. If the wood gets dry in the steam box it's more like kiln drying and the wood gets brittle. Likewise, if the wood is left in the steam box for too long without the addition of more moisture, the wood will also get brittle.

Wet ribs...

The steam boxes:

The steam boxes weren't fancy affairs. As you can see, there are some large propane tanks which feed big burners like are used for a crab boil. A closed top container (loosely closed) is kept fairly full of water. A radiator hose feeds steam to the wooden box which has a rack to keep the ribs off the bottom and a well fitting end cap. The ribs then steamed for 45 minutes.

When the ribs were removed from the steam box (one at a time, starting amidships) they were taken over to the mold and immediately slipped under the rib clamp (the long 2-by at the keel) bent and tacked to the inwale with bronze ring shank nails. The taper of the ribs was kept towards the middle of the canoe and the straight edge of the ribs was aligned with the edge of the steel bands to keep the spacing correct. It took less than an hour to bend all of the ribs on the 16' canoe. We broke one rib at the end where the bend is fairly tight. At the stems, the ribs are held to the stem using bronze ring shank nails that are driven into pre-drilled holes to avoid splitting both the ribs and the stems.

Here are fellow students bending ribs on their canoe:

When all the ribs were in place, the canoe looked like this:

The clamp at the keel is very apparent in the picture above. It is also used to see that the ribs are aligned side-to-side.

I don't know exactly what it was, but I had an awful hankering for a rack of slow cooked baby-back ribs with a smoky-sweet barbecue sauce...

Once the ribs were on the boat, we proceeded to get thwarts, grab handles and a yoke out of some four-quarter Mahogany. It was marked with templates, cut and faired with spokeshaves, rounded over with a radius bit in a router table and then further worked to get an oval cross-section with spokeshaves. A taper was cut on either end of these parts to mate to the angle on the underside of the inwales as well.

Decks were cut from a steam-bent and pressed blank of cherry, the edges beveled to match the inwales and the back was thinned with a gouge to make it a bit thinner in appearance. There is a fair amount of thinning and tapering parts to reduce weight and to gain a more elegant appearance of the finished product. Here's the back side of the deck:

While we were completing these parts, the ribs had dried out enough that we could use some fairing blocks (basically short longboards - is that redundant?) that were coated with coarse sandpaper - 40 grit if I remember correctly - to fair the ribs. Before we faired the ribs though, we used a piece of planking to look for unfair ribs - those that were a bit low or too high. The ribs that were too low were shimmed up using thin wedge-shaped leftover scraps from tapering the ribs. One rib was actually a bit thicker than the rest and we took it down with a spokeshave.

To fair the ribs, we first run the fairing block across the ribs until the scratches run all the way across. Then we sand from the keel down. Special attention was paid to the ribs at the stems to assure that they didn't stick up above the stems.

Once this was done, the ribs were ready for planking and we were done for the day.

Monday, August 25, 2008

Building a Cedar and Canvas Canoe : Monday

I've just returned from another trip up the the WoodenBoat School in Brooklin, Maine. As I noted in my post below, I was taking Jerry Stelmok's class in cedar and canvas canoe building. I've done repair work, but never built a boat from scratch. This was an excellent opportunity to learn the whole process from one of the experts in the field.

On Sunday evening, we met as a class and introduced ourselves and discussed our experience and why we wanted to take the class and what we expected to take away with us.

On Monday morning, we got started in earnest. In the picture below, you see the pre-bent stems, planking and rib stock (cut to rough dimensions) a roll of canvas, and a box which contained seats, extra tools and hardware for three boats. The boats that were built included an Atkinson Traveler (17') , a Model 1889 (16') based on an early EM White design and a solo boat, the Sojourner (13')

The next image shows the end of one of the forms. In this case, it is the Model 1889. What you are looking at is a rigid mold made from a plywood skeleton covered with bent white pine strips. Over the strips are metal bands to clench tacks (more on that later), mounts for a clamp to hold the ribs in place and features to hold inwales and stems in their proper locations. The form is the key to building a good canoe. If this isn't true and straight, the boat will not be either. These forms were (and are) passed down from generation to generation. Some are over a hundred years old and still used to make boats.

The first major task we had was to cut the rib stock to length. This stock is Northern White Cedar. To do this there were measurements on the 2-by used to clamp the ribs in place. We added a few extra ribs in case we broke some as we were building the canoe. The length of the ribs is 4" longer than the distance from gunwale to gunwale. The goal was to have ribs that were vertical grain in the middle and transitioning to flat grain at the ends.

Once the ribs are cut to length, they are then tapered using the jig shown below. This cuts the ends of the ribs down to 1-3/4" at the ends by removing material from one side of the rib. The table saw's throat plate is deliberately removed to allow the wedges to drop free and not jam or kick back at the operator. Two ribs could be cut at a time and knots and bad edges were removed at this time to get nice clean looking ribs.

The ribs were then rounded over a bit on both edges with a router table. The bit was about a 1/2" radius bit and we only used a small portion of it. A stack of ribs can be seen on the table in the rear center of the picture - note the taper at both ends.

After shaping the edges of the ribs, both the finish face and the edges of the ribs were sanded with 100 grit paper. Tedious, but not difficult work with the soft Cedar.

We then installed the inwales on the mold. These are made from Spruce for their light weight and strength. The inwales used on the 1889 had been pre-bent with a steam box to put some of the curvature into them before mounting. We also tapered the inner ends of the inwales as shown below to make the ends "finer". The outer surface of the stem was then coated with shellac to waterproof them.

The pre-bent stems were made from Ash and were made with enough width to get out two stems from the one piece. This is done to prevent the stem from twisting as it is being bent. The bent stem is then cut to width on the table saw. The stem is then cut so it fits into the notches on the ends of the form and marked for the rib positions with a simple gage that looks like basically like a piece of rib. The notches are cut on the bandsaw and are a bit generous to allow for rib growth during the steaming process. A bevel is then cut using the bandsaw that fades out before reaching the first notches. The stem is installed on the form and the edges of the notches are relieved with a rasp to allow the smooth bending of the ribs. The partially finished stem is shown below.

After the stems and inwale were installed, they were wired in place on the mold to hold their shape and position.

To fill the end of the day, the planking was sanded on the finished or inner surface as this would be a difficult area to sand between the ribs after the planking is installed. Again, we sanded with 100 grit paper using random orbital sanders.

At this point, all of the major hull stock has been completed and is ready for installation.

One of my favorite things about the process is the smell. The Northern White Cedar is a lovely smell as you work it. Also, it isn't as splintery as Western Red Cedar that I use to build my cedar strip canoes.

Wednesday, August 20, 2008

Friday, August 15, 2008

Thursday, August 14, 2008

Back Down East

As part of my goal of building "one of each", I'm going back up to the WoodenBoat School. This time, I'm going back up as a student to learn fill out my skills in building wood and canvas canoes under the guidance of Jerry Stelmok. (Pictured below, holding a salesman's sample)

Jerry is an author, artist, teacher and canoe builder and runs Island Falls Canoe in Atkinson, Maine. Up until recently, I was unaware that he was an artist doing sketches and paintings. He's been teaching people to build canoes at the WoodenBoat School and his own shop for about 20 years or so. Most of the canoes that he builds are based on the E.M. White patterns. They are really stunning canoes. Jerry's work as an author is well-known in wooden canoe circles. His books are considered "bibles" in the wooden canoe world and includes these three titles:

I'm looking forward to another week in Brooklin!