Boggs Chairmaking Class in Portland OR

[Deirdre Saoirse Moen]

Day 4: It Ain't Cabinetmaking

Now that the slats have been fitted, we put the bottom legs in a taper jig and bandsaw the taper on the bottom 10" of the legs. Important note: bandsaw with curved part of leg up. Of course, you can also do this step with drawknife, plane, etc.

Scraper tuning

Brian goes over scraper tuning. Someone has a Veritas scraper (he said), but it had been punched out and was thin. Boggs asked someone for an LN scraper. He polished the back and front on a large fine diamond stone, then put the scraper in a block with a bandsaw kerf cut out to hold it vertical for sharpening the edge. Boggs uses a burr (this is, however, a controversial point).

He doesn't use a file until the scraper becomes work-hardened and won't sharpen any more, at which point he stops filing when the file stops chattering and starts cutting smoother.

See his video on the FWW site here.

Let's talk about drillin' holes.

Read Boggs's article about drill bits (FWW 138 or online).

In his opinion, the only reliable brad point bits are from Veritas.

Brian grinds down the spurs. The spurs only need to score deep enough for one revolution. Longer spurs are needed for faster feed rates. For joinery, you really need to go only about 10 thou per revolution, about the thickness of a business card. Most spurs come about 1/8" long, which is too long.

A high clearance angle is one thing that makes a drill bit cut aggressively. Boggs prefers a lower clearance angle, but most are high because it allows a dull bit to still cut.

Boggs hones his 5/8" rung drill bit until it's about 10 thou under dimension. I've got to say, the holes drilled were absolutely gorgeous -- completely clean on the sides and bottom.

We transfered the front rung holes and drilled them, then gathered for "Lesson 42, Part A": figuring out where to drill the holes for the rear seat.

Basically, you need to drill parallel to the chord formed by the slat. Put one slat in each leg, then rotate the legs appropriately. Make sure the slat is all the way home. Sight down the line to a framing square (clamped to a block clamped to the other end of the bench) and see if the angles of the slats are the same.

Someone called this the "slat-o-matic" procedure.

(I know I'm explaining it badly, but it really isn't that complicated, it just seems it)

At this point, someone was stressed about trying to get the joints too close. Boggs replies, "It ain't cabinetmaking." Chairmaking is somewhat forgiving, far more so than some tight joinery. Despite this, his techniques are quite concise.

Then we got to the discussion of how to figure out where to drill the holes for the side rungs, someone asked what the angles would be. Boggs pulls out the jig. "We don't need no angles, we just need blocks."

Maybe it's just that I was mathematically precocious as a kid, but I wasn't entirely sure I believed him. However, it turned out to be right.

"The catch, of course, is figuring out the blocks."

He showed a finished chair, pointing out that the front posts were 16-5/8" center-to-center, and the rear posts were 13-5/8" center-to-center. That's 3" different overall, so 1.5" per side.

Draw a line, draw perpendicular at the front center distances, then draw a line 1.5" in (conveniently, a framing square is 1.5" wide). Draw from each corner to the inner line the calculated length of the side. Now draw a perpendicular line to that, and calculate how far that line is from the first line you drew. In our case, 1.75 inches.

So, basically, if the front rung is elevated 1.5" on one side and 0" on the other, you'll drill at the correct angle. If the rear rung is elevated 1.5" on one side and 1.5+1.75=3.25" on the other, then you'll drill at the correct angle.

We got our fronts and rears glued together (but not to each other today), all with hide glue. Boggs was very impressed with the Behlen stuff. We used 3-lb deadblow hammers to assemble, but in many cases, we needed to use clamps afterward to draw the joints together.

[Deirdre Saoirse Moen]

Day 5: Wrap-up

Wow, it's hard to believe it's over -- it's a little surreal, honestly.

Boggs discussed the two primary differences between his chairs and the classic post-and-rung chairs.

1) His rear legs have a below-the-seat rear curve of 12 degrees. This helps prevent tipping -- it's a lot of work to lean back in that chair, so people don't. Beyond 12 degrees, legs are more likely to break during assembly. The rear legs splay out to the sides as well as to the back, so each side has three different rung lengths.

2) The front corners are tenoned into slats, much like the stool covered in the FWW article (July/Aug 2001).

Typically, the back (above the seat) carries about 17% of the body load. The further the back tilts, the higher this number.

He designed his front corners based on Queen Anne country chairs with seats covered in bullrush. He tried to sell bullrush chairs, but, well, they didn't.

In something flexible, all the weight concentrates on the point of inflexibility (e.g. where the rungs connect).

He puts no shoulders on rungs. The shoulders probably won't hold up anyway, so it'll be visually distracting. Plus, stress concentrates at the point of sudden change of dimension.

When turning rungs, he turns the tenon first.

"I'm ready to demonstrate seat weaving and y'all ain't doin' nothin', so I don't know what to do about that."

99% of what he covered was also on the video he's got out from LN; I highly recommend watching that if you want to use hickory bark.

Use your bigger rolls (of hickory bark) for the warp (front-to-back). Tighten the roll up so it'll stay in a roll as you work.

Soak hickory bark in hot tap water for about 1/2 hour.

Use a girth hitch for the first hitch.

One advantage of a tapered (front-to-back) seat is that it gives you a chance to clean up the edges. Boggs weaves a tapered seat in about 45 minutes; an un-tapered seat in about 25 minutes. He prefers the tapered seats because they look neater.

Eyeball (or mark) the quarters to sync up the front and back when weaving a tapered seat.

Good tension for warp: when the bark stops on its own when you hit the bottom row.

If you have one rough edge on your bark, keep that on the same side as your hand so it's easier to cut.

Bark from Boggs is rolled with the good side out.

Someone asked how he got the bark smooth, did he sand it? Lightly, he said. "What's made that bark smooth is the back of people's britches."

When creating a knot, make the tongue for the knot about 1/4" wide.

The whole bark of a hickory tree is about 1/2" thick. Boggs takes the inner 2/10" and cuts it into two layers. The inner layer he calls first cut (and doesn't sell; it's reserved for his clients only); the outer cut he calls second cut and that's what we were using.

And we all assembled our chairs. Several people (but not me) wove their seats. I figured that would be easier to do *after* arriving home.

After class and after I packed my car up, I got to meet up with Steve Knight and GregP -- had a great time!

More pics will be up soon, but perhaps not until I arrive home. I'm TIRED.

[Mike Leigh]

Hi Mike--welcome.

Gary Rogowski's school is the Northwest Woodworking Studio
http://www.northwestwoodworking.com/

Just on the East side, not far from Steve Knight's shop.

Take care, Mike

Great! Thanks much, went to the website, but alas.....in my case, ignorance is not bliss, '
where is Steve Knight's shop in Ptd.

[Deirdre Saoirse Moen]

Here's the link with Steve's shop address.

[Mike Leigh]

Deirdre,
Ok, got it...thanks again......

[Pam Niedermayer]

...
He doesn't use a file until the scraper becomes work-hardened and won't sharpen any more, at which point he stops filing when the file stops chattering and starts cutting smoother.
...

Deirdre, I can't parse this. What makes the scraper work hardened? At which point does he start filing?

Thanks,
Pam

[Deirdre Saoirse Moen]

Well, I was taking notes quickly. As I understood what he meant, repeated burnishings of a scraper would lead to a situation where it couldn't easily be sharpened any more (what he meant by work-hardened), at which point he'd get out the file.

He did mention that the file would chatter with the first couple of passes; when it cut smoothly, then it was time to sharpen because one had removed the hardened bits at the end.

Until I experience this, not sure I fully understand it, but at least I've now more fully described it.