Showing posts with label sharpening. Show all posts
Showing posts with label sharpening. Show all posts

Friday, September 23, 2016

Making mine smaller


Here's the reground tip with the piece I broke off.

The shortened tool, ready to go to work.
As I learned from David Sander's book on engraving, and as I've heard from a couple of full-time engravers, the tools I got from Lyons (via McClain's) as well many of the tools that came from my recent  Ebay purchase are too long.
For proper engraving the "mushroom" handle fits in the palm of the hand (and is the driving force) and the point of the tool should be at or just beyond the ball of the thumb for control and leverage.
Many tools were sold much too long and had to be shortened.  That was left to the engraver, but usually the tool would be put in a vise, and a sharp rap with a hammer would break off the tip, and a new point had to be sharpened (or the shank end was reground to fit in the handle).

It's hard to get up the courage to break off 1/3 of the working edge of the tool you just bought.
It feels wasteful and I wasn't sure I was up to proper sharpening.
BUT, I want tools I can use, and several of these; a couple of angle tints and scorpers are missing from my tool kit and needed on the block I'm currently carving.

So I've been doing 1-2 at a time, snapping them off, and then grinding them down with water stones to 30-40degree bevels and taking the time to get them really sharp.

I'm cutting the legs of a mosquito, so I need very sharp tools that I can control (and decent magnification).
More soon. 

Saturday, September 5, 2015

Home-made Honing Disc. Getting tools sharp enough for moku hanga.


I don't know if the WorkSharp (TM), an American-made, motorized, disc sharpener for woodblock tools comes in a 220V version, but I was worried that the size and bulk made buying and bringing one to Italy in a suitcase impractical (especially since I was already 20kg overweight with blocks and paper).

But since TWO of our neighbors design shoes and handbags (another odd perk of living in Italy), we get the occasional leather remnant and I have a few pieces lying around. AND one of the cardboard pastry discs I use for my barens was way too big to use for a baren. AND I have 8 sets of Powergrip tools that I need to sharpen after my last moku hanga class for a workshop I'm giving this weekend.
So the odd juxtaposition of need, on-hand supplies, a model to use as a starting point, and the imminent need for 8 sets of sharpened tools got me motivated to try something I'd been thinking about.

 I took the cardboard disc and drilled a 8mm hole dead-center.
Then I glued the thin leather to one side with PVA glue (thinned a bit with water). To the other side I glued a 1500 grit wet sandpaper and pressed them both beneath some books overnight to dry.

Today, I loaded the leather side with honing compound (from McClains) and then threaded a long, 8mm bolt through the hole with washers on either side, and nuts to hold the disc tightly when it spins. I placed it into a handheld portable drill that I clamped to my table and by sitting just right (with safety glasses), I could hold the drill power switch with one hand to control the speed while looking  down the edge of the spinning honing disc and carefully place my U-gouges against it at just the right angle, turning them as I did so to finely hone the outside edge of the tool. By looking down the edge of the spinning disc I can hone on the top side with the leather wheel or hold the tool on the underside to lightly grind with the 1500 grit. I used a tightly rolled up piece of 1000grit sandpaper to remove any burr from the inside of the curve and looked at it with a 10X loop. Nice and polished. It took the hairs off the back of my arm with just a light touch. 
And just to be sure, the leftover piece of Okoume plywood that was tearing with the same tool yesterday, now cut cleanly and smoothly with no shredding.
We're in business.
Next, I tried the 1500 grit side of the disc on the Hangi Toh, I have to be careful not to get the tool hot or I'll lose the temper of the steel so I never held it for more than a few seconds at a time on the wheel and even the 1500grit takes metal off faster than I'd like so I do have to be careful.  But I put a new bevel on the Toh in less than a minute (on/off, on/off) and then buffed it on the leather side.

I made another disc (this time with a pressed-wood disc that came pre-drilled with a 8mm hole) it was for a decoupage clock face (3 Euro at the craft shop) and I glued a 600 grit and 1000 grit wet/dry sandpaper sheet to either side.
These will be used only for changing bevels and really dull tools.
The drill is held in a vice so I can power it with one hand while I can gaze down the spinning wheel and hold the tool against it. There is leather and honing compound on the top, a 1500 grit paper on the bottom half.


The stiffer disc was definitely an improvement though as there is no wobble so it's easier to keep the bevels even and true.  (And I think I'll try to convert my leather one to the stiffer disc as it's a little easier to control). But first:
Tomorrow I'm going to hone the 8 sets of Powergrip tools for my class.
While I do this regularly by hand (using waters stones of 1000/6000 grit) on my good knives but with this many tools, I think the honing disc will get them all sharp enough for the students in about a 1/2 hour.
More importantly, they'll be sharp enough that they'll carve the plywoods easily, and that will make the work easier for beginners.