|Forum topic by Mark Colan||posted 07-20-2013 04:52 PM||1405 views||2 times favorited||15 replies|
07-20-2013 04:52 PM
I have mainly been a power tool woodworker, but recently bought some used planes – a #3, #5, #7, and a little trim plane that I don’t know what it’s proper name is. The total was around $200 from Tool Barn, Bar Harbor, ME, a great little store. I already had a small block plane and some chisels from my Dad, and one I bought, that need work. I never liked hand tools like these because they seem so difficult to use. Well, of course they are not, so long as they are properly sharpened, but I have never done that. I also own some nice kitchen knives that could be sharper and want to learn to sharpen them like a pro.
Obviously the time has come to learn to restore and sharpen blades. I have a Chinese dual-grit stone intended for kitchen knives, and no experience. So I started reading about various kinds of stones, the things you need to do to keep them flat, guides, and so on. Expensive, and inconvenient.
Somewhere someone mentioned Brent's Sharpening Pages . I like the idea of starting simple, so this appealed. I thought it would be a cheap way to start. It’s not, exactly, though it is less than the stone and guide approach.
As I embark on tooling up for sharpening, and then actually trying to sharpen, I’ll write here about what I learn. I would welcome any comments from those of you who are experienced with sharpening. Keep in mind that I am starting as an absolute beginner on the subject, aside from knowing how to use a steel on a kitchen knife.
You can think of this as a review of my experiences of using Brent’s extensive documentation on the subject.
Overview of Brent’s System
In a nutshell, Brent’s system relies on two kinds of jigs. First, there is a piece of glass with abrasive film attached via adhesives. The glass is glued to masonite, and the masonite will have a non-skid material on the bottom so it stays put in use. He recommends three grits, so there are three glass jigs.
The second jig is a guide designed to hold plane blades, chisels, etc at the right angle. Brent tells you all about how to make them, as this is really the heart of his system. He suggests making guides specific to the width of the blades you sharpen. I have not studied them yet, but I think he has a different guide for chisels.
I ordered the glass at a glass store. I figured 1/4” plate glass would be better, until I got a price on four 6×16” cut pieces and it was like $92, because they had a minimum piece price for 1/4” glass. They also have a minimum of $5 for 1/8” glass (total $21.25), and I went for that. I don’t have much experience with glass cutters, but I think I could have done better had I taken the time to shop around.
Brent recommends Weldbond for the glue. It does not seem to be available locally, and I wanted to work on the project this weekend, so I used a glue called E6600 clear medium viscosity that I got at an arts and crafts store. It was just over $7 for a tube and I used most of it. It specifically includes glass and wood as materials it glues.
He suggested some kind of non-slip fabric for the bottom. No experience here, but the hardware store had this rubbery (actually latex, I think) lacey stuff that is designed to put under carpets. It was about $8 for a 2×4’ piece.
Last, the abrasive films. Probably not available locally, but I got a basic supply from a place in NY delivered Friday when I ordered Wednesday. Brent recommends three grits: 15, 5, and 0.3 microns, and he recommends the kind with self-adhesive backing. The place sells a package with two sheets each of those, and since the 15 micron is said to wear faster than the others, I ordered some extra of that grit.
I had a scrap of 1/4” masonite big enough to make the protective bases for the glass.
Assembling the Glass Plate Abrasive Jigs
Brent recommends sanding the edges of the glass because it can be sharp from the glass shop. In my case, the glass did not seem sharp, almost certainly because the glass cutter sanded them a bit, but I sanded them more and rounded the corners anway.
I cut the masonite to size, about 1/2” larger than the glass on width and length, to have 1/4” borders around the glass. Brent does not tell you how big to make it. I had meant to make it a bit extra long so I could put a hole in the top to hang on the wall for storage, but due to operator error, when ripping to length I had the wrong setting.
Next step was cleaning the glass before gluing. He did not say to do that, but for appearances and adhesion it seemed like a good idea. Then I put glue on the perimeter of each piece, a line down the center the long way, and three lines dividing the other way into equal sizes. I then attempted to spread the glue with a scrap, then pressed the plate onto a board.
The E6600 glue is not as viscous as I had hoped: it did not spread well. Perhaps Weldbond spreads better. They are different glues; in particular, E6600 is clear out of the tube, and Weldbond comes out white but is said to dry clear.
The critical thing is that the glass stays flat. Pressing it to spread the glue could cause it to be slightly uneven. However, it cannot flex much the narrow way, which is the more critical dimension; flexing the long way is probably not a problem for even sharpening. Also, I suspect that since the glass wants to be flat that it will even itself out a bit.
You may think I’m worrying about nothing, but I figure if tolerances of 0.3 micron (the grit of the finest film) are at stake, that would be the maximum unevenness I could tolerate, and probably I need much flatter than that.
Brent suggested taping the corners to prevent drifting while it’s starting to cure. I used masking tape to tape two opposing corners for each board.
Later, I can go back down and glue the backing on each. I’m taking a break because we’re at the end (I hope!) of a heat wave, and I’m not big on working hard in the heat. Still plenty hot today, but cool air is supposed to finally move in this evening.
I will include pictures in this work, but for now, there’s just text.
-- Mark, hack amateur woodworker, Medford (greater Boston) MA