If you’re new to scraper planes or scrapers in general, you may want to read this first.
My Lie-Nielsen #112 scraper plane has become indispensable to me since I purchased it about a year ago. Whether I’m dealing with exotic woods, interlocking grain, or just smoothing a knot with the usual grain reversal surrounding it the scraper plane does it all and I would not be without one at this point. But maintaining a scraper plane can be tricky and unlike hand planes, there isn’t a lot of information out there on how to set them up. Hopefully this will help (so please tell your woodworking nerd friends).
I start by taking the blade out (TIP: push it out through the bottom of the sole so you don’t ding the cutting edge) and cleaning out any debris. My handles were a bit loose, so I snugged them up while I was at it. I also removed the cap screw, cleaned off the threads, and added some oil to it before re-installing it.
Next I took some freehand test cuts with the blade to see if it was still sharp. It produced mostly dust so it was time to sharpen.
The blade is sharpened just like a plane iron, except I use a straight edge (not cambered) with my scraper plane. The bevel is also honed at 45 degrees, much higher than the 25-30 degrees found on a typical bench plane.
With the blade polished, I turn a hook. This is similar to forming a hook on a card scraper, but because the edge is at 45 degrees (card scrapers are honed at 90 degrees), I just apply some pressure to the tip of the bevel with a burnisher to create the burr or hook. This can take a little practice, but you will quickly learn what a “good burr” feels like.
With the hook formed, I start taking test cuts by hand and look for two things. First, is the hook where I want it? If it’s too large I’d have to grind it off and re-sharpen (though that’s never happened), if it’s too small I can put it back in the vise and increase the hook with more pressure and more passes from the burnisher. The second thing I look for is the optimal cutting angle, which is a little different every time as the hook is turned by hand and isn’t 100% identical from one sharpening to another. I hold the blade at the desired angle and adjust the frog assembly to match. This way I know when the blade is installed I’ll be getting the best shavings possible. The adjustable frog is not a feature found on smaller scraper jigs like the Stanley #80 and it’s one of the major benefits of using a dedicated scraper plane.
Now I simply install the blade (again, through the bottom of the plane so the hook isn’t damaged by sliding through the frog assembly) and set everything flat on the bench. Make sure there are no shavings or debris preventing the tool from laying dead flat. Press the blade down so it touches the bench firmly, then tighten the cap screw. This should leave the blade more or less parallel to and flush or just below the sole of the plane. Take a test cut. If the blade is skewed or not protruding far enough, minor adjustments are made with light taps from a small hammer. Brass is preferable so the blade isn’t damaged. I own one from Lie-Nielsen and another from Sterling Tool Works. Both work great.
After a little trial-and-error you should be getting wide, fluffy shavings with a tear-out free surface left behind. Once I was satisfied on my scrap piece of walnut I had some actual work to accomplish on some Bocote and Chakte Viga. No problem… except that Bocote smells like a wet dog.