Sharpening, ad nauseum

Re: Sharpening, ad nauseum

Rick Hoppe (Los Angeles)

>Gerry, my thoughts:

1) IMHO this is a kind of apples and oranges kind of thing. The equivalency charts are all over the map. It's been my experience that 2000 grit paper is roughly equivalent to 8000. I think the grit on the paper breaks down more quickly than the stone and also the surface of the paper becomes burnished rather quickly, rendering the tool more polished than with the stone.

2) A 1 degree back bevel on a plane blade is OK (not OK on a chisel). As for the curved edge, when flattening backs it really pays to flatten the stone FREQUENTLY. David Charlesworth says after every 100 strokes. I just check the stone regularly with a good straight edge. Much of the time a slightly curved edge is a good thing (if the curve is created on the bevel side.

Re: Sharpening, ad nauseum

Jim in Burlington Ontario

>Shiny is not sharp. No matter what stones you use if your technique is bad it needs work. See if someone can show you a technique if not I would reccomend would be David Charlesworth video. Sounds to me like your rushing the whole process.

Re: Sharpening, ad nauseum

Gerry Doll

>The slight convex profile was originally from a pi$$ poor grinding job. I assumed the profile would loose it's convexity if honed on plate glass w/ 150 grit SC. There's the rub. The convex profile is still there, just smoother now.

My thinking was that any irregularities from a perfectly straight edge left from the grinding would be corrected when honed using an eclipse style jig on plate glass. This does not appear to be the case. Wouldn't honing with eclipse eventually wear away the convex profile??

Re: Sharpening, ad nauseum

Gerry Doll

>Jim,

With the amount of time I've spent with plate glass, reams of sand paper, cans of spray adhesive, razor blades, cans of adhesive remover, and flattening waterstones, I don't think I'm rushing anything. As a matter of fact, it appears that my progress has been more of a crawl. A learning experience, but so is one's first prostate exam.

Gery

tired of blowing metal dust from his sinuses

Re: Sharpening, ad nauseum *LINK*

Jim in Burlington Ontario

>Gerry The rushing part is when you are sharpening you take a few strokes wipe it off and have a look. When using a jig it's all finger pressure. It's very tough to describe sharpening yet easy to show someone if you only you lived closer. There is a little tutorial on LV site just go down to instr highlighted in blue and have a look thru maybe it will be some help.


http://www.leevalley.com/wood/page.asp?page=33001&category=1,43072,43078&abspage=1&ccurrency=1&SID=

Re: Sharpening, ad nauseum

Rick Hoppe (Los Angeles)

>Gerry, the Eclipse style jig has a very narrow roller the jig rides on. This makes it very responsive to finger pressure along the edge. Ergo, this is a jig that may require a little more skill to control if what you want is a straight edge. The Veritas with its wider roller is more stable and, I think, easier to achieve a straight edge.

You sound a lot like me when I started sharpening. I had a tendency to overwork each stage especially the final honing part. It�s a drag being on the uphill end of the learning curve.

I agree with Jim. Get the Charlesworth video.

Re: Sharpening, ad nauseum

paul womack

>Pursuant to my research, a 6000 water stone is of significantly finer grit than 2000 grit sand paper.

Not according to this reference.

grit size comparison. If this chart is true, they're comparable.

...straighten out while honing on 150 grit SC paper. Using an Eclipse style jig, I ended up with a convex profile.

This is a known issue with sandpaper, especially if not glued down. SiC wears quite quickly, it tends to wear more in the middle; further the swarf builds up more in the middle.

The result is that the centre of the paper cuts less well than the edges, resulting in a crowned blades. The effect is less pronounced in finer grits, so I tend to just let it happen, since I normally desire my blades crowened to some extent.

If you want a straight blade, use wide, fresh SiC to reduce the 2 effects described above.

This issue also applies to plane sole flattening by lapping, both side to side and end to end, resulting in convex soles.

BugBear

Re: Sharpening, ad nauseum *LINK*

Brent

>Gerry

It may well be that the crucial part of your problem is contained in the phrase "honed using an eclipse style jig on plate glass".

Before you try anything else, put the blade into the jig as you normally do the put a straight edge across the back of the blade. Did tightening the jig bend the blade?

I noticed this way back when and it started me off on devising my jig for holding plane irons. Check out the link to my pages on plane iron sharpening and testing.

Brent


http://www3.telus.net/BrentBeach/Sharpen/jig.html