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Slow speed 1750 rmp 6" buffer/grinder for Gouges?

I use slow speed grinder for most sharpening, finsihing with DMT plates and 6000 grit water stone. Works to a mirror finish  and saves much time.  Does  hollow ground matter? Thanks, Capt.Earl

Hello Capt.

There are many ways to approach sharpening and my advice is to find what works for you and stick with it. It's O.K. to experiment with new ideas if you see some advantage with a new method however. Most carvers prefer to have a straight bevel or a convex bevel to facilitate scooping cuts. It all has to do with the geometry of the tool shape as it moves through the wood, leverage for tool control, and burnishing of the cut surface. An explanation for that is probably best left to a longer discussion. Hollow grinding can work well for many other woodworking tools however. A straight bevel can still be achieved on gouges by simply grinding the tool at 90 degrees to the wheel rotation or by stoning the tool until the concavity becomes flat, and then relieving the change between the bevel and the tool body. Slower grinders and water cooled grinders help to prevent overheating the tool but an experienced craftsman can get perfectly acceptable results with a standard grinder if care is exercised.

It should be noted that grinding is only necessary when doing any initial shaping, when doing repairs or restoration, and is not considered normal everyday maintenance practice. Don't forget to give the internal surfaces proper attention during sharpening or you are only doing half the work necessary to get the tools into proper condition. Slip stones and even wet/dry sandpaper on dowels works well for that. I personally never sharpen on any stone finer than 1200 grit and then power hone/strop to a mirror finish.  When the edge loses the preferred cutting ability then simple honing/stropping can return the edge to prime condition. On those rare occasions when honing/stropping isn't enough I simply return the tool to stone enough to develop a slight burr and then hone/strop.  Above all else, honing/stropping on a regular basis can be very quick and works wonders in making carving an enjoyable activity. Have fun.

Michael Stiennon has reacted to this post.
Michael Stiennon

I wanted to add that I have tried finer stones but if you are honing/stropping (especially power buffing) anyway it doesn't affect the final edge in any significant way and just adds time and cost to the process.  Have fun.

Earl & Michael, I have to put my 2 cents in here. First off, let me say that when it comes to sharpening tools, I've never been satisfied with the results of using a buffing wheel or electric sharpening belt. I have 2 different kinds, and only use them when I am carving in wood that eats up the tool edge quickly (like every 5 minutes) such as teak, southern yellow pine, cypress. All of these woods have silica in them and dull gouges quickly. I would be spending more time sharpening than carving on those woods.

The main reason I do not like to buff my gouges on a machine is that I always end up getting a slightly rounded or softened bevel. And if I use a buffing wheel a lot, the shape and definition of the gouge is lost - even the sharp corners of my favorite fishtails. I have not figured out how to use these machines and not get that result. So after I finish my project where I need to buff my tools every 5 minutes or so on a machine, I put them back on the stone to flatten the bevel. This shortens the life of a tool much more than if I just stuck with a sharpening stone.

As you mentioned Michael, using the tools to "gouge" is fine for a rounded bevel. However, I use my gouges quite often in a "planing" motion where I sweep across a surface, bevel side down. If there is any slight rounding to the bevel, this "planing" motion wants to gouge instead. The tool needs to be lifted slightly higher on the wood for the blade to cut, and wants to "scoop" rather than "plane".

But then again, I'm kind of a purist when it comes to sharpening. And that's just me...

 

Bernhard Baumgardt has reacted to this post.
Bernhard Baumgardt

It al goes back to the first sentence in my post. Yes, a buffing wheel will round the edge but I have found the results to be negligible unless the wheel is run at an extremely slow speed and/or the tools is buffed too long and then all bets are off. I have used leather strops and have experienced about the same amount of rounding even with minimal stropping. I have used hard strops of MDF and maple and they haven't made a significand difference for me in the performance of the tools. I have found the buffing wheel to be a quick and effective way to go from stones to a sweet working edge or to refresh an edge. I do find, as you suggest, that the process is a little harder on the corners if you are not careful but those are quickly restored at the stones if need be. Since I am a hobby carver and not a professional I recommend trying Mar's methods and then trying other methods to see what works best for you. Have fun.