Tuesday, September 13, 2011

Acrylic for Diamond Paste Sharpening Surface

On the advice of a more experienced diamond paste sharpener (thanks Peter!), I looked into using plexiglass (acrylic) or copper for a sharpening substrate.  It turns out the plexiglass was much cheaper and more available; I went to a local industrial plastics shop and dug through their scraps bin.  Found some 1/4" plexiglass for $4, and they cut it into three 3 1/4" x 8 1/4" pieces for me for $5.  The $5 for cutting was cheaper than buying a carbide-tipped 80 point blade for my table saw.

Then I cut matching 3/4" MDF pieces and epoxied the MDF to the plexiglass to make substrates for three diamond pastes.  I think I'll end up using a coarse (25-40 micron), then a 6 micron and finally a 1 micron paste.   In the photo below the MDF is getting epoxied to the plexiglass.

And here are the final results in the sharpening station.  Note the holdfast on the left, which is being held in the bench deadman, to hold the station in a fixed position while sharpening.

Sunday, September 11, 2011

Working with Ipe

I decided to use Ipe charged with diamond paste for one of my sharpening stations.  It has a Janka rating of 3680 and is pretty difficult to work with.

I had a long piece of Ipe about 2" thick.  It's pretty easy to cut with a crosscut saw.  Here is my sawbench.

I decided to square and flatten it using handplanes rather than dragging out my powered jointer.  Don't like the darned thing anyway.  Here I am going at it with a jack plane with a cambered blade.  It worked pretty well.

Next, the #8 jointer was put to work to flatten it.  Think thin shavings, then make it thinner.  I had several "power out" moments until I got the right setting.  And the approach of picking up the plane and putting it to work without sharpening the blade was a non-starter as well.  It was skating along the top after a few strokes, so I broke out the sharpening stones.  But I was able to get one side and one edge flat and square.

This stuff will make you and your equipment look like The Hulk - colorwise, anyway.  It also left some waxy-looking crud on my plane blades that I had to scrape off.

Then I ran it through the tailed planer to get the other two sides flat and square.  Next, I tortured my poor little 10", 1/3 hp Rikon bandsaw by ripping it to about 1" thickness.  It was slow, but it cut it just fine.

Sent it through the planer one more time, then cut three blocks to length.  Here they are in the sharpening station, ready for diamond paste.

And finally charged with diamond paste, and put a secondary bevel on a blade.

Sharpening Stations

I have been working on my sharpening technique lately, and to enhance the experience I've built a couple of sharpening stations.  Sharpening stations are not a new thing, but these have a different twist - they are made from 3/8" sheet PVC, fused together with Weld-On 2007 (I used epoxy on the first one, but switched to the Weld-On for the second one).  This makes for a nearly indestructible unit that can be hosed down to clean it; it's very practical.

The first one has a 325x diamond plate and three sigma power waterstones, and can be used with an eclipse-type jig.  The five little stops at the front register the blades in the jig at 25 - 45 degrees, in 5 degree increments.

The second one is meant to be used with the Oneway Grind 'N Hone jig.  It has 3 blocks of Ipe of uniform size, charged with 6, 3 and 1 micron diamond paste.  I selected Ipe as it was the hardest wood I had available, with a Janka rating of 3680.  A primary hollow grind can be ground using the grinder, and you can go directly to the sharpening station with the jig, and put the secondary bevel on, using the diamond paste.  Here's a pic before charging with diamond paste.

And after charging with diamond paste and putting the secondary bevel on:

It's a good idea to label the blocks with the micron sizes, because after a while they all look the same dark color.