Ripping on the super saw bench…

If you fancy yourself a craftsman of wood, then you are no doubt familiar with the countless people that ask you to build/repair/customize/take a look at/help them with all manner of projects involving wooden goods and furniture.

I am always amazed at the boldness of people like this, whether they are complete strangers or quasi relatives, they always seem to assume I/we are the most capable people in the world. How do they know I’m not some half-crazed nut job that likes to chop the legs off  of Hepplewhite highboys with a chain saw??!?!??

Anyway, I’ve been mistakenly referring to myself as one of these alleged “craftsman” for some time, and thankfully, over the last few years, I’ve gotten quite good at dodging these oh so tactfully poised inquiries into my willingness to work on whatever jackass crown molding job or shoddy antique refinishing boondoggle people have laid at my feet. I will say, however, that there are some requests that I am more than happy to oblige. Those are the ones that come from parents and grandparents.

Call it respect for one’s elders, or reverence for those we owe our existence and prosperity to, but I do enjoy helping close family. Hell, I often suspect that the only reason my family hasn’t disowned me by now is that I may be the only one in the family that has half a chance at not cutting off a limb or burning the house down when home projects are undertaken.

Anyway, when my mom asked me a few weeks ago to make a table leaf for her antique white oak dining table, how could I refuse? I know its something she’s wanted for a while, and seeing as its her birthday next week, I figured it would be a marked improvement over my usual gift of, well…nothing.

Fortunately for the readers of my blog (or not, depending on your preferences) this little project actually contains some great saw work…..YAHOOOOO!!!!

So let’s get down to brass tacks…

The table is made of quarter sawn white oak, and thusly, I purchased a nice 8 foot board of about 7 inches wide. Since the leaf will have a finished width of 11 inches, and you always want to balance your laminations, I need two 5 and 1/2 inch wide planks. And you know what that means, boys and girls……….its rrrrrrrrrrrripping time!

This is a great chance to show off my new SuperSawBench that I finished a few weeks ago. I’ve been doing a lot of cross cutting on my new bench, but haven’t had a chance to do a lot of ripping….so lets try it out….

I’ll use my trusty Wenzloff/Disston #9….here she is all limbered up…

When I first started ripping on a saw bench, it took me a little while to adjust to it…especially the ripping notch, but now that I’m used to it, it certainly is the go to spot. And I start by marking my cut line on the board and aligning it in the center of the ripping notch…

Positioning your body correctly is the most challenging part of learning to rip at the saw bench…..because it has to FEEL right to you. And what feels right to you may not feel right to someone else, so its difficult to describe how to do it correctly for that reason. The point is, you need to be relatively comfortable as you start the rip, so you can focus on keeping the saw moving and the cut square, not on how much your back hurts. In this case, a picture is worth 1000 words…

If you recently read BobRozaieski’s article in Popular Woodworking about ripping with a hand saw, then you know how important it is to center your eye over the spine of the saw plate…this is how you are most inclined to saw straight, square and true. Here’s what you should see as you are about to start sawing…

Can you see my pencil line marking the cut? Nope! That’s how you know you’re lined up straight…and that’s how your view should be from start to finish….if not, you’re liable to cant your saw out of square. Not good.

After I get the saw started, I have to inch the board forward every few seconds to keep the saw from cutting into the bench top. Once you get the hang of this, you kind of instinctively nudge it forward as needed with your rear foot or left (non-sawing) hand. Here you can see clearly how the ripping notch functions: each side of the notch supports the work while allowing you to cut deeper into the board without cutting the bench…

About halfway into the rip, the board starts to cantilever out into nowhere, and ripping can become a little tedious….so here’s why many craftsman of old recommend building saw benches in pairs…

…for outfeed support!

As I get towards the end of the rip, I need to pay close attention to securing the board. I no longer have the benefit of using my right knee as a home-made hold-fast, so I make use of my other meat clamp (my hand) and apply firm pressure…

The other way to accomplish a rip like this is to cut halfway through and then turn the board around and cut the other half from the other end, that way you don’t need to worry about the out feed support. But then you have to get a little more creative with holding the waste side of the cut…kind of a pain in the butt, and much easier to cut off a thumb nail….DAMHIKT. 😦

All done!

I think ripping a board like this is just about the most fun you can have in the shop (at least without strippers, anyway).

Yes, its work, but if you’re afraid of work, what the hell are you doing in the shop, right?

-Matt

Published in: on March 28, 2011 at 6:31 pm  Comments (8)  

Rake and Rip saws…

The first time I got my hands on a proper rip saw was, unfortunately,  a bitter-sweet experience.

It was sweet because it was the first moment of the rest of my woodworking life….like a door had been opened to a place that was fun, fulfilling, and free from the threat of lung cancer and systematic dismemberment. But it was bitter because I was frustrated with the performance of the saw….and just so you know, the saw wasn’t from Home Depot or Ace Hardware. The saw was a vintage Disston D-8 with a thumbhole from the classic 1896 to 1917 era…we’re talking about the greatest rip saw ever made by human hands. And it was professionally sharpened by a well-respected saw guru. So what was the problem?

Well, the saw was gorgeous, perfectly tuned, sharp as English wit, but to my inexperienced hands, every time I stroked the saw through wood, it was not a pleasant experience. The teeth felt like they were sticking in the wood…and like I had to push really hard to get them to cut. I could feel the moment each tooth sheared a chunk of fibers from the board, and that feeling reverberated from the teeth, to the saw plate, to the tote, to my palm, and up my arm to my shoulder. It was jittery and rough and un-nerving. And I was pissed.

What the hell?!?!? This was not the zen like experience I had read about in the pages of books and magazines…this was a hands on demonstration of why people started the asinine folk art craze of painting on hand saws instead of using them!!!

Well, like most things in life, it turns out knowledge really is power. And in this case, the knowledge I didn’t have about rip saws was disempowering me to use them. What I quickly learned was that hand saws, much UNLIKE powered saws, require an intimate knowledge of their form and function to use properly.

Any toothless caveman can go to Home Despot, buy a $99 table saw, plug it in, and be ripping white oak all day long like he was Norm Abrams. But to do so with a hand rip saw requires knowledge of the physiology of wood, body mechanics, and saw tooth geometry.

So which one was I missing?…..the one about saw tooth geometry, and in this case, that was the most critical absence. You see, what I did not yet understand about rip saw teeth was the fundamentals of tooth rake. And the rake was what was making this saw cut like a jack hammer.

Rake, or “pitch” as it also is traditionally called, (not to be confused with the common, modern designation of pitch meaning tooth spacing) is the measure in degrees that the face of each cutting tooth is rotated back from 90 degrees relative to the tooth line. The illustration below (from Disston and Sons “Lumberman Handbook”, 1907) demonstrates two different rakes….

In the first image is shown a saw with 0 (zero) degrees of rake. The face of each tooth is 90 degrees to the tooth line, and in effect not raked forward (like Japanese saws) and not raked backward.

In the second image is shown a saw with 12 (twelve) degrees of rake, meaning that the face of each tooth is rotated back 12 degrees from vertical (90 degrees from the tooth line).

So, what’s this have to do with how a saw cuts? Lots. And lots. And….well, you get the idea. Which is this: the greater the teeth are raked back from vertical, the less resistance the teeth encounter as they cut the wood. So teeth with zero rake–meaning the cutting faces of each tooth are 90 degrees from the tooth line–will cut more aggressively and meet with more resistance than teeth that are raked 5 degrees back from vertical (relative to the toothline). Make sense? Good.

I should also point out that the more teeth are raked back, the less aggressively they cut. So before you go and file 25 degrees of rake into all your rip saws, you should know that by doing so, you’re effectively turning them into giant bread knives. Not good for wood!

So, can you guess how much rake was on the teeth on that fortuitous first D-8?

Zero degrees. And if you’re paying attention at home, you now know that means that the face of each cutting tooth was 90 degrees from the tooth line…just like in the first illustration above.

And that’s why my first nice rip saw–though perfectly tuned and filed with a precision that would make even ole Henry Disston proud–made me want to call the guy I sold my table saw to and beg him to sell it back to me!!!!! But I didn’t give up. In stead, I started filing my own saws and here’s what I figured out…

The reality that I discovered about rip saws, is that there’s a sweet spot relating to the rake of the teeth. And by that, I mean you have to strike a balance between relaxing the rake to cut smoothly, and still have it be aggressive enough to actually do some work. For me, that sweet spot is about 5 degrees of negative rake for most saws with 6 or 7 points per inch, and about 5 to 10 degrees for more course toothed saws. You can play with the range of rakes, but anything much past 10 and you start to lose a lot of performance from your saw.

The other important point to mention here is that I work mostly with hard woods, and hard woods are the ones that respond nicely to a little relaxing in the rake department. If all I was ripping was white pine and even a little poplar, I’d probably be okay with zero rake rip saws. But the truth is, I work a lot with white oak, maple, cherry, locust, walnut, etc….some very hard woods. And believe me….a little relaxed rake goes a looooooonnngggg way. Those 5 little degrees that each tooth is swept back turn them into sweet little stanley #80 scraper blades….very nice! As opposed to zero rake teeth, which act more like a dull scrub plane iron on end grain. Ch-ch-ch-ch-chattering teeth anyone???

And just in case you’re curious, here’s some pics to illustrate…

First, is a 5 and 1/2 point saw with zero rake…given the tooth spacing and rake of this saw, I can comfortable rip pine, fir and poplar…

And here’s one of my favorite rip saws….a Wenzloff 5 point with 10 degrees of negative rake….and she is a sweet ripper! This is the saw that I used to make TheBigRip. Mike Wenzloff, smart guy that he is, recommended this rake and damn if he wasn’t right as rain. 🙂 I use this saw to do all of my heavy ripping…anything 8/4 and up in white oak and the like….

So, that’s the skinny on rip saws and rake. I encourage you to pick up a few and check out the rake, start filing and never stop trying new things.

I have to remind myself every day that this slippery slope of hand tool work is littered with unsolved mysteries and long-lost skills begging to be rediscovered.

Here’s to the next revelation!

-Matt 🙂

Published in: on March 10, 2011 at 9:05 pm  Comments (17)