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John Piwaron
02-25-2003, 9:11 AM
I bought a couple of Sorby turning chisels last night, my first ones. I noted that the grind they come with is significantly rougher than how bench & mortise chisels are sold.

So what's the deal here? Is the buyer of one of those chisels expected to finish sharpening it? Or is that all that's needed for turning?

Bill Grumbine
02-25-2003, 9:34 AM
Hi John

I can't speak to the comparative smoothness of the different grinds, but I can tell you that sharpening lathe tools is something that is very frequent and very individual, so most tools are going to be reground to the user's taste and technique. While there are a couple of tools that come with a preground profile that is wise to keep, quite a few end up being changed to the point where it would be impossible for a manufacturer to try and anticipate.

As far as the frequency goes, you will find that sharpening becomes a skill that you will use all the time when you turn. It is quite different than it is with many other tools, in that they are sharpened and then touched up periodically. Often a turner will change grinds for effect, to experiment a bit, or just to make a certain cut.

Good luck with it. It appears that there will be a healthy number of turners here from the Pond, so there should be lots of interaction.

Oh and I almost forgot to add, I grind my tools with an 80 grit wheel, and in the past have used a 60 grit wheel. With either I can get very smooth surfaces off the tool with no stropping or honing.

Bill

John Piwaron
02-25-2003, 11:54 AM
O.K., sharpening is important. It looks like the bevel could be smoother, but the real bothersome thing is the burr at the cutting edge. That can't be good for cutting wood. I'll stone it off and see what happens.

BTW, I *just* got my lathe at the Milwaukee woodworker show last weekend, it's a midi lathe with the Fisch brand on it. So I'm really new to this. I got those chisels last night so I'd have something to use. Not much use even opening the box without 'em.

Angelo Schembari
02-25-2003, 12:27 PM
In my limited experience, the burr has little or no effect on the cut. It has seemed to me that oun gouges the burr peels off almost immediately. Hopefully Bill or someone else more knowledgeable will chime in and correct me if I'm wrong.

BTW, I rarely hone off the burr on gouges.

Richard Allen
02-25-2003, 12:44 PM
Rubbing the bur off with a stone is a simple matter which will have more of an effect on your sensibilities that the removal of the bur will have on the ability of the gouge to cut wood.

Yes removing the bur will make a cleaner cut. But not so much that you would notice. I don't remove the bur from most of my woodturning tools.

If you want to remove the bur go ahead and remove it. But be sure to sharpen the tool often. How often? That depends on how you use the tool, what species and other things. Figure on sharpening a LOT. Several times an evening (if that is when you get a chance to turn).

Thanks

Bill Grumbine
02-25-2003, 1:22 PM
John, the burr is insignificant in the scheme of things. It comes off in about 0.0001 seconds if you stick the tool into some good hard wood. On one of his tapes Richard Raffan demonstrates removing the burr on his roughing gouge by bashing it into a block of wood.

Much more important are the "ears" on gouges, specifically spindle or bowl gouges (roughing gouges have a good profile from the factory). If you try and follow the factory edge on most gouges, you will end up with wood orbiting about your head, possibly broken tool rests or tools, and a flinch not unlike that developed by some shooters of high powered rifles. ;)

There are some pictures in the BP archives of how a bowl gouge should be ground. Spindle gouges are not a whole lot different. The longer the grind, the more aggressive the tool will be, but at the least those ears need to be knocked off.

As an aside, which I will eventually post in a separate posting, if you, or anyone else here is going to the Going Away Party for the Pond at Ray Thompson's in Anderson IN, it looks like I will not only be there, but I will be demonstrating at the local AAW chapter during their regular meeting that weekend. I am sure there will be other demos thorughout the weekend. :D

Bill