Tuesday, July 17, 2012

Scary Sharp for Danger Boy

A couple weeks ago I ordered a few Groz hand planes from Woodcraft during their big clearance sale.  I was able to pick up a block plane and the #3 and #4 bench planes for Danger Boy.   Late one night, with the rest of the fam tucked in, I fired up an old Wood Talk Online podcast episode and cleaned up these new additions.

They were heavily coated in “shipping goop” so a lot of WD-40 was dispensed!  They cleaned up nicely, and some checking with machinists squares revealed that they have pretty darn flat soles.  I was expecting to have to do some serious work to flatten the bottoms, but I was pleasantly surprised all around.

For my own tastes I would want to upgrade the blades with some thicker Ron Hock blades, but I think these will serve as great intro planes in the meantime.  They were in need of some serious sharpening through…and how sharp is sharp enough for Danger Boy?  SCARY Sharp!

I’ve been using this sharpening method for my planes and chisels for years now and have always been rewarded with great results.

The first steps were to set up the various grits of sandpaper on my glass plates (I use 3M’s Supper 77 spray adhesive) and to break down the block plane.  I use eight different grits, starting at 220 and ending at 2000. (220, 320, 400, 600, 800, 1000, 1500 and 2000)

The hardest part of sharpening a blade for the first time is flattening the back.  A truly sharp edge is only created by two perfectly flat surfaces coming together to form the cutting edge.  All the hard work is done on the 220 grit paper and can take a fair bit of time to work through.

The goal is to work the back of the blade on the sandpaper until all the scratches in the surface are uniform.  After working the blade through two pieces of the 220 grit paper, you can see that there was still a bit of work to do on this blade.  That cloudy looking area still needs to be worked out.

Another sheet of 220 and we’re getting closer.

Yet another sheet of 220 and another dose of elbow grease and we’re finally there!

I’ve turned the flash off here to show the scratch pattern.  This is what you’re looking for, a surface that is completely covered by the same pattern of scratches, in the same direction.

Once this has been accomplished on the lowest, hardest working, grit, it’s a much easier task to work your way up through the next levels of sandpaper.  They key is to make sure that you’ve removed the scratches from the previous grit and that the pattern gets finer and finer all the way up to your final grit.

After working all the way up to the 2000 grit paper I had a mirror smooth finish with no perceptible scratch pattern at all.  Say cheese!

Not only does it keep my coffee hot, but my Woodworking for Mere Mortals mug is the perfect tool to test the reflection of the flattened surface.  I’d better tell Steve…he can start charging more for these babies!

With the back flattened and polished to a mirror finish it was time to tackle the bevel.  I set the blade up in my Veritas honing guide and locked it down at a 25 degree angle.  Since this is the first sharpening on this blade, a fair bit of time was spent on the 220 grit paper.
As with flattening the back, the goal is to work toward a uniform scratch pattern on the bevel surface before moving onto the next grit.  I worked the bevel all the way up through the 2000 grit paper.

The coffee mug test reveals that mirror smooth finish we’re shooting for.

The lighting makes it a little tough to see, but this honing guide incorporates a feature that allows you to change the sharpening angle by 1 or 2 degrees so that a micro-bevel can be applied to the edge.  With the indicator at the top of the barrel, the guide sharpens at the set angle…in this case the 25 degrees I selected.

Rotating the barrel into the lower position changes the sharpening angle to 27 degrees.  This allows for just the tip of the cutting edge to be honed to this increased pitch, making the edge stronger and less likely to chip or dent.

Another tour through all eight grits and you can now see that secondary bevel at the cutting edge.

After some clean-up, I reassembled the block plane and took it for test drive on some scrap Poplar.

Full width and full length shavings from the very first pass!  Not bad!  We’ll just call this a small victory though as there are still the blades for the other two planes that need to be sharpened.  I’m not scared though!



turningoutnicely said...

Thanks, an interesting post.

Pete said...

Thanks bud!