Wednesday, May 23, 2012

CGSW Inaugural Class

The workbenches set up in the shade at the entrance to the barn at Brookdale Farm. Why work inside on a day like this?

The inaugural class at the Close Grain School of Woodworking this past Saturday was a spectacularly gorgeous spring morning. I had two students, Reeve Goodenough and my daughter, Shelby. Thanks for being the first to sign up, Reeve!

Several people have asked if Shelby has continued her interest in hand tools, and I'm happy to say she has. You may not realize what a sacrifice it is for a teenager to leave the house at 7:30AM on a Saturday! (You can read about her boatbuilding project at school, and dovetailed box at home.)

Part of the reason for being so early was to get things setup on site. I had to unload two of my newly-built Paul Sellers workbenches and re-attach their vises.

Some last-minute tuning up: the inner jaw was rubbing against the guide rods when moving the vise. I removed the jaw and planed the bottom to provide clearance.

Suddenly we saw a large shadow sweep across the ground and heard the rippling of a canopy. We looked out and saw several skydivers spiraling down. Remember I said this was just across the street from Skydive Pepperell?

A tandem jump pair.

I'd also like to mention that we share space in the barn with Restore Hockey, a charitable organization that restores used hockey equipment to deliver to programs, families, and individuals who would otherwise not be able to play the game.

The topic of the class was sharpening. I gave them a safety briefing (we are dealing with sharp tools here) and pointed out the location of the first aid kit, then described the vociferous differences in opinions about how to sharpen. I presented these as a series of choices about methods, media, and bevels. Jig or no jig? Strop or not? How much to strop?

After outlining the various bevel choices and basic techniques, I went over five different sharpening media and their characteristics, then had them try each one:
  • Sandpaper on flat substrate (aka "scary sharp" or Mike Dunbar's "sensible sharpening", in this case using MDF substrate)
  • Oilstones in my portable sharpening station
  • Waterstones
  • DMT Duo-Sharp diamond plates
  • Hollow grinding on hand-cranked grinder
My goal was not to say any one is best, but to give them a chance to feel for themselves what each was like, what feedback they get from the abrasive. Put an edge on, test it out, dull it on the sandpaper, and try another. Try different grinding patterns and bevel shapes. I showed them jigs, but encouraged them to develop free-hand skill.

Then they can make a more informed choice moving forward. That choice may change as they get more experience, developing more control and gaining confidence. Much of the technique refined on any one is transferrable to another.

Reeve has been using sandpaper on granite plate; Shelby has never done any sharpening before. To test their results, I had them take end-grain shavings on pine and oak.

After they had a chance to try the different methods, I showed them how to sharpen and set saws using a saw vise, and how to sharpen and use card scrapers. As usual, the 3-hour class flew by, but we were able to cover a lot of material and try a lot of hands-on work.

Shelby examining a chisel edge while sandpaper sharpening, as Reeve tries out the oilstones.

What a beautiful day!

Reeve sharpening one of his mortise chisels.

Shelby testing the edge of her chisel after using the DMT Duo-Sharps. She felt most comfortable with these because she was worried about gouging up the surface of the sandpaper and the stones.

Closeup of the fine pine end grain shavings she was able to get.

Reeve had gotten the same Lie-Nielsen card scraper free with his subscription to Fine Woodworking as I had, but hadn't known what to do with it. Now with a few minutes of instruction and practice he was able to take nice feathery fine shavings.

He and Shelby both tried sharpening and setting several inches of rip and crosscut saws, then went back to chisel sharpening. But they were both able to see that saws can be sharpened quickly.

The skydivers continued to drift down all morning, a lot of tandem student jumps and a few solos.  You could hear the difference, because the solo jumpers tended to come in faster, canopy roaring before flaring at the ground. Too fast, in fact, for me to get any good photos of them.

A tandem pair heading for the ground target.

Coming in for a landing.

A pair swooping around. This looks like fun!

If you're interested in taking some group woodworking classes, check the schedule, or you can schedule your own private classes.

Saturday, May 19, 2012

Building A Paul Sellers Workbench, part 2

(Go back to part 1)

The next step here is to form the housings in the aprons, again using Paul Sellers' techniques.

Deepening the knifewall on the left side housing.

On the right housing, after knifing the line, chiseling a chip out down its length.

After chiseling both sides of the right housing, wasting out the middle.

Final cleanup of the housing with a router plane.

That's a snug joint. Test fit of the leg frame in the housing without any glue.

Securing the aprons to the legs. The legs are just friction-fit into the apron on the floor here, to hold them in place while attaching the top apron. That's the advantage of snug joints, to temporarily hold things together.

Screwing the apron to the leg after gluing. The screws hold it together so I don't have to wait for the glue to dry. Things proceed quickly at this point. I flipped the assembly over and secured the other apron.

With the bench up on its feet, drilling the pilot hoes to screw the top to the front apron after gluing and clamping.

Using a phillips-head hex bit in a brace to set the long screws the last half inch. This produces enormous torque, so go slow to avoid damaging the screw or overdriving it into the hole.

Ripping the well-board to rough width to fit in the back section. I did the final fitting with a plane. Then I laid the bench on its back and screwed the bearers into the top and well-board from below. I also added battens under both edges of the well-board so it doesn't sag in the middle under the weight of tools.

Trimming off a quarter-inch from the end to flush everything up. Then I cleaned up the end grain with bevel-up smoother and block plane.

At this point, the bench itself was complete. Next was attaching the vise. There are basic instructions on the Highand website, with more extensive instructions for this specific bench in Paul's book and DVD. On this bench, I did a better job than the first one, because I formed shoulders in the cutout to support the front of the vise. These vises weigh just under 40 lbs. so they need to be attached with heavy lag screws. However, since Paul doesn't mortise his vise into the apron, and the apron is 1 1/2" thick, the front mounting holes in the base are unusable. The shoulders make up for that.

Boring large holes at the corners of the cutout.

Chiseling grooves to connect the holes.

With the grooves thinning the stock, sawing out the cutout with a keyhole saw. I cleaned up the edges with a chisel.

The vise sitting in the cutout. The screws are pointing to the shoulders, which fit the base of the vise snugly.

Using a ratchet to drive the lag screws in the rear mounting points. There's a spacer made up of two layers of plywood to position the vise at the right level relative to the top edge of the bench.

Drilling the mounting holes for the oak jaw. The inner jaw screws through the rear vise face into the front apron and top. Between the lag bolts, the shoulders in the apron, and these screws, this vise is solid and secure.

Trimming the two jaws to rough height after screwing them into place.

Flushing the jaws down to the top of the bench, first with the #5, then the #7.

The bench ready for use after chamfering all the end grain edges with a block plane and chisel.

I removed the vises to transport the benches, since they add significant weight and throw them off balance taking them up the basement stairs. It also helps to have a son home from college and one of his buddies.

After unloading the benches at the school, I reinstalled the vises. The following photos compare the vise cutouts and mountings.

The first vise cutout, left, and the second, right. You can see the shoulders in the second one to support the front of the vise.

The first vise in its cutout. The screws though the rear vise face provide the only front support. Not good.

Underside view of the first vise.

Underside view of the second vise, with a good fit between the shoulders and the vise base. Note also the deeper cutout in the center, providing better clearance for the quick-release mechanism to open. After noticing that, I took a chisel to that part of the first bench, since it was jamming a bit.

I'll glue and screw some support blocks to the inside of the first bench's apron to bear up against the vise base. That will provide the same physical support as the shoulders in the second bench.

Students will enjoy working on these. If they need to build a bench at home, this is an excellent choice.

Building A Paul Sellers Workbench

How many workbenches do I need? I have my large Schwarz/Roubo workbench in the basement, my Roy Underhill portable workbench that I take to offsite classes and demos (and I have a second partially built to accommodate more people), and now I need four for the Close Grain School of Woodworking. Seven is the lucky number.

I like the workbench in Paul Sellers' book and DVD series Working Wood, so when I started the school, that was the design I chose. The combination of book and DVD provide an excellent guide to building it. He also addresses the issue of how to build a bench when you don't have a bench to work on. You can read my review of this series here.

This bench has a number of nice attributes. Built from construction-grade 2x4's and 2x6's, it's inexpensive (about $65 in materials, excluding the vise), so is affordable in multiples. It's a nice size, beefy without being too heavy. I can fit two of them in my van, possibly even all four, since I shortened them by a foot. It's also very sturdy, a combination of the laminated 2-by stock and the interlocking joinery. At that, it's simple to build.

It's also a time-tested design. Paul says it's been used in Britain for centuries, and he uses it in both his UK and US schools. The structure consists of two mortise and tenon leg frames, with aprons housed on them. This mechanical interlock provides excellent rigidity. The thick laminated top is secured to the apron, with a simple tool well behind it. With the addition of a traditional cast iron quick-release vise that itself weighs 40 lbs., it provides a solid work surface for students.

The design can also be adapted easily. As I mentioned, I shortened mine to 4', making it easy to build with 8' stock. That's the size of my portable workbench top, and I've found that to be adequate. Paul builds his at 38" high, which I found a bit too tall (but of course it depends on the individual). I made mine 36" and 34". The depth can be increased by additional laminations, and the size of the aprons can be changed. I also  omitted the quarter-round molding in the tool well. Other than that, I followed the design exactly. I did notice after building two that I had oriented the leg laminations rotated 90 degrees from his, but that shouldn't be a problem.

Here I've documented building bench #2. I kept a good record of the time required. Excluding waiting for glue-ups, it was 28 hours of labor spread over 2 weeks. As with my Roubo, I did everything with hand tools, except that I used a benchtop planer to plane down the 2x4 edges to eliminate the rounded corners. Building these is good for practicing Paul's joinery techniques.

For the vise, I used the Anant version of the Record 52 1/2 ED quick-release vise, sold by Highland Hardware. Watching Paul work in the DVDs convinced me to spend the extra money for quick-release. He just goes zip-zip-zip moving workpieces in and out of it very efficiently. I have non-quick-release vises on my first workbench (oh, yeah, I forgot to count that one, 2x4's, plywood, and MDF, but it no longer counts), and they're slow and annoying to work with.

After planing, I worked on the top. I staged the glue-ups for the top and legs so that whenever I had anything in the clamps, I had other parts to work on. One thing I didn't do, that I did on the first one, was to run all the 2x4 faces through the planer. This resulted in poorer laminations than the first one. That was a pretty dumb mistake. Functionally, all the laminations are sturdy, but aesthetically they're not as good.

The top glued up.

I ran the planer on bench #1.

Flattening the top, starting with a #5 diagonally across it for heavy stock removal.

Final flattening with a #7, sighting across winding sticks to check for wind.

With the top flattened on both sides, I worked on the leg assemblies. First I planed them up clean and square.

Trimming a leg to length. The way to get a clean, square cut is to cut about 1/4" deep, then roll the piece, repeating for all four sides. Each little bit of kerf already established helps guide the next. Keep repeating until all the way through. Note the auxiliary bench hook on the right to support the far end of the piece.

The four legs trimmed and marked so I wouldn't get things mixed up as I fitted each joint.

Mortising a leg, using Paul Sellers' mortising technique.

Cutting the haunch in the top mortise. The haunch provides the twist-resistance of a full-width joint, even though the tenon will be only partial-width, due to the location at the top end of the leg. The actual tenon needs to be cut to fit this haunch.

Cutting the shoulder in the tenon on a rail.

Cutting the cheek of the tenon.

The tenons on the lower rails protrude 1/2" in the Art and Crafts fashion. Paul shows several possible end treatments. I chose to round them with a plane, then round off the corners with chisel and rasp.

Assembling the leg frame. The spacer blocks accommodate the protruding lower tenons.

The frame glued up.

Trimming the upper tenon end flush with a block plane.

The leg frames are attached to the top and well-board with bearer boards. I haven't used this method before. The bearers are predrilled with two sets of holes, then screwed to the top rail of the leg frames through the first set of holes. They'll be screwed to the top from the underside through the second set of holes.

For the screws that will secure the top, predrilling the holes  at an angle.

Countersinking the holes on both sides.

Drilling the pilot holes in the top rail of the frame.

Glue-and-screw the bearer to the top rail.

With the leg assemblies complete, the next step is to cut the housings in the aprons, which I had already hand-jointed and edge-glued from 2x6's.

(Continue to part 2)