Monday, June 14, 2010

Class Report - Saw Sharpening at St. Roy's School

Short version: I took a one-day class on Saturday at the Woodwright's School in Pittsboro, NC. The topic of the class was Saw Sharpening. It was great and I finally figured out what all this fleam and rake and gullets and such really meant. I recommend for anyone who wants to learn.

Much longer version:

Now I hear some of you snickering at the n00b, but it is a skill that while simple in its foundation, is, for me at least, best learned by example rather than trial and error.

The class was taught by one of Roy's local teachers, Bill Andersen, who has been teaching classes in the area for some time now. Bill did a great job introducing us to the various tools and implements used for saw sharpening. We each had a bench with an old saw vise and we brought our own saws, but there were plenty there that needed sharpening.

We were just able to get through doing a rip saw before lunch, and a cross cut after lunch. I finished early enough to then re-tooth one of his back saws which looked like it hadn't been touched in 50 years.

We started on the rip saw because it is much easier to learn on than the crosscut. I had brought two Simmonds, a 6-point rip and an 8-point cross cut. Both had been re-toothed and sharpened quite a while ago when I first came to NC (2003) by a saw sharpening service in Raleigh. I was under the impression that these saws worked fine but only needed a quick touch-up.

We began with jointing the saw, filing with a larger, flat file held perpendicular to the teeth, and run straight down the tops of the saw teeth. Boy, was that an eye-opening experience. This saw was not so beautifully toothed as I thought. I had to take a fair amount to touch most of the teeth. I ended up with about four teeth down the length of the saw that were still just too short for me to reach. Bill said that was fine, you'll get them eventually as you sharpen it, either next time or the time after.

We then re-shaped the teeth to get the right rake. I began at the heel of the saw, down by the handle, and there's a good reason to do so, because when you screw up there, it doesn't really matter too much since you almost never saw with those teeth. Good thing too. I made my first big mistake, and was grateful for having someone there who knew what they were doing. First mistake was thinking I could keep my file at the right angle without a help. I got about six teeth down when Bill came by and gently pointed out my very common mistake, I was filing my teeth with a 30-degree rake because I was following the natural reaction to have the top face of the file become more and more flat as I filed. He suggested I use on of the very simple, but extremely useful, wooden blocks he had made that help give you a reference face for the right angle. Stick the block on the end of the file, and keep the block horizontal and you'll be ok. Big difference. You can see one of these very simple devises on Pete Taran's saw filing page.

This is where a teacher-led class can more than pay for itself. Bill showed me what I was doing wrong before I had ruined all the teeth, and he showed me how to fix it.

I got my money's worth again a short time later when I made my second big mistake. I was getting the angle right, but this time, because I was trying to "fix" the teeth that I had filed at too sharp of an angle, I was getting a bit aggressive with the file. I was trying to shape AND sharpen at the same time (without really knowing that's what I was doing) and as a result every other gullet was way deeper than the one I hadn't done. Again, Bill was able to come to the rescue and help me figure out that I was doing it wrong, and how to fix it before I did too much damage.

After that, things went more smoothly. I ended up having to re-joint the teeth a couple more times before I got them shaped like I wanted. I then did a light jointing, set them, and did a final sharpening. Bill showed us how much to stone the side of the saw to adjust the set and I was done.

We had each tested our saws at the beginning for the "before" cut. We tried cutting to a line and see how far ten strokes took us through the wood. After sharpening, we tested the "after". My saw had too much set at the beginning, which is why, I found out, that it had a tendency to vibrate a lot in the cut. Afterwards, I cut about a third longer in the same number of strokes, the kerf was cleaner and I didn't have nearly the vibration I had before.

The crosscut saw after lunch went much more smoothly, even with the added complexity of also filing the fleam into the teeth. We shaped the teeth like it was a rip saw, except the rake this time was 25-degrees instead of 8-degrees. Then finished shaping with adding the fleam. This time I was a much lighter touch with the file, and kept a rhythm while also watching each tooth carefully. This saw also had way too much set that graduated with almost no set by the heel and way wide set by the toe. It had so much that I actually didn't need to set it at all. The filing had taken off just enough set that it seemed fine.

I finished early enough that I thought I'd try my hand at a backsaw. In the pile of saws that needed sharpening was a nice brass-backed 19th-century British saw that had teeth but they were in a sorry state. By getting good light, and using a light, consistent touch, I was able to get it re-toothed as a rip quite quickly and easily. That was extremely satisfying to see those old, raggedy, nasty teeth turn into shiny, consistent teeth. The saw was so nasty that the teeth were already black with crud and age I didn't need to blacken them. For the other saws, we had used an alcohol based carbon blacking spray which worked like a spray paint. That was really easy to spray and mark each tooth to make sure you knew which one you'd done, and which ones you hadn't. It cleaned up with alcohol.

So, if you're interested in learning how to sharpen, this is a great class. And I'm so glad I've finally gotten a chance to learn how it's done, and had it de-mystified for me. It's now time to make a couple of those jigs to help me keep a good angle, and find my saw vise in the dust and I'm in business.

Monday, December 7, 2009

Mini bench: part 2

I left off last time having cut the half-lap joints. Now I wanted to glue them together and pin them. I'm still not sure what, if any, benefit I'll get from pinning, but since the floor of the half-lap joint is so rough from the pine lumber's propensity for splintering, it will give me an extra piece of mind.

As I often do, I first made a template to work off of.

I just used the width of my ruler to figure out where to place the holes from the top and bottom edge, and just placed them an inch in from each side. It seemed a good enough placement.

I drilled the holes.

Then I used the template and drilled the holes, glued up the boards and drove 5/16" dowels through. I could have made my own square or octagonal pins, which I've done before, but one of the guiding principles of this project is quick and dirty, so pre-made dowels is it. I tested one before hand and the dowels were actually quite respectable in terms of roundness and fit into the hole, so they were fine for this use. (though I would still love to have a dowel plate)

After the glue dried and I cut off the pins with my new flush-cut saw (Happy Birthday!) I started to plane down the surfaces to get a nice fit and take off some of the marks that had accumulated from the various operations.

This is where the leg vise really showed its stuff. I was able to clamp up the leg assembly and hold it both at the top and bottom of the leg vise.

Once I figured out where to place the pin in the parallel guide, that sucker held the leg assembly like it was an act of God. I could have been chiseling out mortises, or cutting the very end and it would have held it perfectly still. I really like my leg vise.

As it was, I was merely planing down the edges, and then used the wagon vise to do the faces. Edge, face and ends, that's what you need to be able to do, right Mr. Schwarz?

Overall my bench works beautifully. I do need to get my sliding deadman in place for my next project as I'll be making a longer table top, but for this small project, it couldn't have been better.

After finishing the planing I just set the mini bench on top of my own with the top just sitting on the legs. Now the top of the legs will be mortised into the top, so it will sit further down onto the cross piece.

As you can see, the joints are tight, but not terribly pretty. That's what happens when you go fast using cheap wood.

After putting it together like this, I decided that I need to make it a little wider. The proportions weren't quite right, and I think it will be more useful for what he does, which is mainly whacking on wood and storing his (one) tool on his bench. (his hammer) I'm also seriously considering flipping the legs upside down and putting the stretcher across the bottom. We'll see where I go with this next time.

Wednesday, December 2, 2009

Mini bench

When my son began to express interest again in coming into my shop and hammering on nails, or, as he did last night, working the wagon vise for me as I showed him how to chop out a half-lap joint, I decided to make him his own scaled down bench.

There were a couple of considerations:
1. It was going to be useful for only a short period of time before he outgrew it.
2. It had to stand up to hammering and nailing, most likely at some point directly into the bench so I had to be sturdy, and cheap so I wouldn't care that it got banged up
3. His woodworking needs are limited, including probably no planing at this point
4. It had to be out of materials I had on hand.

So, I settled on a bunch of 2x6 and 2x4 lumber I had sitting around my shop for years and which were bone dry at this point. It was thick enough to give some solidity, cheap enough to not worry about him trashing it at this point, and easy enough to work with.

The Bench Top

I started with the top. I jointed a couple of 2x6's and glued them together.

Nothing pretty, but solid enough. The boards were also a bit wanky. That's my technical term for slightly cupped, not flat, even a little wavy in places.

I could have flattened them individually before jointing them, but since they were so small, I decided to get them glued and then tackle them together as a single surface.

I first trimmed them to length.

Then I began with my old German scrub plane.

You can see the kinds of shavings I was getting. I didn't set it to be very aggressive because this pine will splinter like anything if you try.

After that, I began the diagonal traversing. You can see what happens when you have no camber on the blade and go across grain.

The last step was to plane down the grain with my #3 to smooth out the marks from the other planes. I also ended up taking some passes with one of my #6 planes as a kind of joiner plane before my #3 but it all seemed flat enough for my purposes so didn't spend much time before jumping right to the smoother.

And here is a little display of the different kinds of shavings that result from the different operations. I dug through my shaving pile and found, from left to right:

Scrub plane chips - Early traversing short shavings - Longer shavings from traversing - Thicker shavings along the grain to take down the high spots left from traversing - Final thinner shavings from smoothing.

The Base

The next time I was in the shop I began the base. Here I'm going back to my supply of dry, cheap construction lumber. I think 2x4's are sufficient for the legs. I figured just half-lap joints to affix the front and back cross pieces, made out of a scrap 1x4, and some simple through M&T joints for the end cross pieces. My design at this point is to mortise and tenon the base into the top so I figured to leave some wood above the half lap for this.

I decided to put the front and back cross pieces up just under the top because I wanted to leave the bottom as open as possible for him to stand, and the size of the bench and the lack of much clamping up at the top made this possible. I figured I can always flip the legs upside down as I get them built and put the cross member at the bottom if I decide to.

This is indicative of another aspect of this project I wanted to explore: improvisation. I'm working pretty rough and pretty imprecise. I'm using the material itself for measurements so I have no idea how big any of this is. If I were to take more care with this, as I certainly will for his next bench when he's old enough to actually do stuff, the proportions would have been different, and I would have taken care to shape and size the various components to look better together. As it is, I have a feeling it will look a bit odd once it's finished, but I'm looking to spend as little time making it while still having it be functional for its limited requirements.

So, I started cutting the legs.

Using one leg to indicate the size of the next

You can see the precise layout tools I'm using reflect the obsessive drive for perfection in this piece.

Using my bench hook I first trim

Then do a quick squaring off just using my bench hook as a quick-and-dirty shooting board rather than get out my dedicated one. This is part of my drive to do this as quickly as possible.

After getting the legs cut and squared, I figured out about how far apart they were by using a scrap of 2x4 as spacer. I need the legs far enough apart so that the bench is stable, but want to leave some room on the ends so I can do through through mortise and tenons to affix the base to the top.

At this point I started to touch up the surfaces of the legs. I don't need them perfect, just better than straight-from-the-borg 2x4. I'm shooting for "flat enough".

Here's a good indication of how the board itself told me I was flat enough. This wood has been in my shop for at least six years, some of it may very well be older. It has a kind of oxidation to the outside of it that is darker than the inside wood. The two pictures below show you what one board looks like as I start to flatten it. Notice in the first picture the contrasting lighter and darker areas. The lighter areas are the high spots, and the darker are the low spots after a pass or two. Once it all looks the same, as in the second picture, I know I'm done. Good enough.

I looked for a short piece of fairly narrow stock for the end cross pieces. I found this wanky piece of very soft wood. I'm not even sure where or when I picked it up. At first I thought it might be maple, but planing it was so easy and it was so soft that I suspect it's basswood. But good enough.

And now I have my material.

Cutting the joints

Layout was simple. I used the top as indicator of how far down I needed to take the half-lap joints I was going to use to join the front and back cross pieces to the legs. I left a little material on the ends assuming I'll trim it flush to the top.

I used the cross piece itself to figure out how wide to make it.

I used the material again to determine how far into the wood to cut. At this point I decided not to go with a half-lap but to take advantage of the thicker legs and just cut the full thickness into the leg. That's one less part of a joint to cut. Quick and dirty, but functional.

I cut to the lines and then started hacking it out with my chisel and mallet. You've got to be careful because this pine will splinter past your line if you just look at it funny.

I used my old router plane to sneak down to the final depth.

You can see the bottom of the cut is still not too pretty, but it got better with subsequent joints. I learned to stop hacking with the chisel sooner and cut with the router plane longer.

Voila! A couple of half-way decent joints for quick and dirty.

I have all four of these joints cut now. Next I will actually put them together and then work on the end pieces.

Tuesday, November 17, 2009

A good time in the shop is ...

Getting the chance to introduce your GIT (Galoot in Training) to the joy of pounding nails.

I know it's almost cliche, but for some reason it is a very effective hook. I think it was getting to use a real hammer instead of his little plastic one.

What he really enjoyed was when I showed him how to use the claw to take some finish nails out of the board. Once he figured out how to do that, he was taking them out and putting them back in again over and over.

This gave me a chance to build a four-foot French frame for my second prototype. this frame includes two 1x3's for the sides (poplar) and two of the cleats were ripped from 1x3's.

But the most fun was working with the GIT.

Sunday, November 15, 2009

Workshop Crawl and Wood Purchase

Went on the workshop crawl with the North Carolina Woodworker group. It was a lot of fun meeting in the flesh those with whom I've already met virtually. And we got to see six interesting shops with some very different approaches, work and methods.

My favorite, because it speaks to the way I work, was John's shop. After an episode of Fun With Tablesaw Kickback, John discovered the joy of hand work. He has turned his garage into quite an amazing workshop.

From the very Schwarzian saw bench:

to the massive logs lying around for riving (Peter's name was mentioned a time or two)

to the very nicely executed Roubo

it was definitely a shop after my own heart.

But what was really extraordinary, as you can get a hint from what was on the workbench, is the extra tool he built in order to make the posts of the bed he is building. You see one lying on the workbench,

but another is still in process.

Yes, that's a seven foot spring pole lathe. He did an amazing job of building it and it seemed to work quite well.

Overall, a very fun day.

I did leave the crawl with more than pictures. I picked up a couple of pieces of wood for very reasonable prices.

I don't have a lot of wood beyond some left over pieces of maple from the workbench, and some dimensional borg stuff, so there's not much of a wood cache to pick from. Which is ok since I'm not able to do much work anyway. But I couldn't resist these two pieces.

One is Sapele. It is 4/4 rough sawn, a little over 10" across and almost exactly 6' long. What really attracted me to it was the figure and the price.

Even with the lousy light in my shop last night and with it still being pretty rough sawn (I took the top most fuzz off with a few passes of a plane, but it's still pretty rough) you can still see the grain popping out.

One for scale on my five-foot bench (didn't even try to correct the horrible light)

And one with a flash.

This one I'm going to have to think long and hard how I want to use it.

The other board I picked up (with great difficulty, if truth be told) is a rather large piece of quarter-sawn red oak. It's about 17 inches wide, by 90 inches long. It's 5/4 rough sawn, and like the sapele, even rough sawn the grain pattern pops right through.

Here's one side:

And for a real close-up

And the other side:

And to get an idea of scale in my shop:

And here with a one-foot ruler:

The rays and flakes are more pronounced along one edge of the board and extend about half-way in. I'll have to think about how to use this. I didn't get a pair of bookmatched boards from the same tree as this piece and about the same size. I may regret not having the option of making a two-board, quarter-sawn oak table.

Regardless, it's fun to have some wood around for inspiration. Another step further along in my evolution.