Archive for ◊ September, 2019 ◊

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• Monday, September 30th, 2019
sharpness tests

Knife Grinders is one very serious bunch of sharpening experts. Located in New South Wales, Down Under, their website is full of interesting information. What particularly caught my interest is their detailed list of sharpening tests that can be done with simple equipment, notably hair. 

I recently posted about the sharpness tests that I use, but these guys have refined things to an ethereal level. Caution here, it bears repeating: the only fully meaningful tests of a sharpened edge are its performance and endurance in its assigned task. We also must consider appropriate edge geometry and endurance.

But check out the Knife Grinder’s list. I like the arm hair shaving gradations on page 1. The hanging hair tests (pages 4-5) are intense. 

Maybe you think this is fetishizing sharpening beyond practical woodworking. OK, maybe it is, but it is nice to know that there are convenient, fairly standardized ways to test how your sharpening procedures are performing. To get scientific, one could get a BESS tester from Edge On Up

You probably have your own sharpness tests but I suggest taking a look at that list. It’s pretty cool. 

Category: Techniques  | Leave a Comment
Author:
• Saturday, September 28th, 2019
compression wood

Being a woodworker, and thus appropriately obsessed with wood in all its variety, I could not resist grabbing a sample slice of a mildly leaning hemlock tree that was recently taken down on my property. 

On the left side of the slice, which was the underside of the leaning tree, note the darker, wider latewood in the enlarged growth rings. That is “reaction wood,” specifically called “compression wood” in softwood species. 

compression wood

How does this relate to shopping for wood? A board with end grain as outlined in the photo would show signs of trouble:

  • The deduced location of the pith is off-center even with an equal number of annual rings on each side of it.  
  • The width of the annual rings is asymmetric on opposite sides of the pith.
  • The wide annual rings contain that odd looking latewood. This will probably also be noticeable on the face of the board.

The compression wood is abnormally brittle and weak. It also shrinks a lot along its length, whereas normal wood has essentially no such shrinkage. This can result in splits, crooks, and finishing problems. This is a board that you do not want.

These boards are definitely out there lurking in stacks of softwood lumber (hardwoods have their version of reaction wood known as “tension wood”) and they’re just waiting to give you trouble. Leave them behind.

Category: Wood  | 2 Comments
Author:
• Saturday, September 28th, 2019
tablesaw

Oops, I had a SawStop “event.” But it was not my flesh that met the blade. Rather, I foolishly forgot to reset the miter gauge fence when setting up an angled crosscut, and ran the aluminum fence into the blade, and . . . boomp! So, I had to send out the damaged blade for repair along with my spare blade that was damaged 14 years ago when I was setting up the new saw. This, plus buying a new SawStop brake, made for an expensive goof up. All told I’ve lost use of the tablesaw for four weeks.

But, I’m doing just fine, thank you. In fact, the episode has reinforced my longstanding conviction and advice that the tablesaw is not the key machine in the furniture maker’s shop. In my view, that distinction belongs to the bandsaw, especially when it teams up with a good thickness planer, or better yet, a wide jointer-planer combination machine. 

Far from being a hand tool purist, I was happy ripping on the bandsaw with surprisingly little clean up required with a handplane. I also cleaned up lots of 15/16″-thick, 3″/3 1/2″-wide pieces by standing them on edge going through the DW735 planer with the Shelix cutterhead. I made sure the rollers and bed stayed clean, and it went well.

bandsaw

“What about crosscutting,” you say, “that’s not likely to go well on the bandsaw.” Well, using the little miter gauge that came with my bandsaw, the crosscuts are pretty accurate and not too rough even with my all-purpose 3-tpi blade.

Which brings me to another longstanding conviction and advice. And that is the importance of shooting. It was a pleasure to clean up the bandsawn crosscuts cleaner and more accurately than even the tablesaw could do. Shooting is so critical to accurate furniture making that I suggest sparing no effort and tools to set up good systems for end grain and long grain shooting. (I’ll describe my current long grain setup and have some tips in an upcoming post.)

I won’t be selling my tablesaw – it does a lot of tasks efficiently and well. However, I do want to reinforce this advice regarding machines, especially for woodworkers setting up or upgrading their shops:

  • The first machine to buy is a good portable thickness planer. The DW735 has no peer.
  • As soon as you can, buy the best bandsaw you can. Steel frame style, at least 12″ resaw height, preferably something close to 2.5 HP or more.
  • Get a 12″ jointer if you can.
  • And sometime, yes, you’ll probably want a tablesaw. 

Most important, no matter what tools you have, build things.

Category: Tools and Shop  | 10 Comments