Power grinding primary bevel: What do you use?

[Thomas Colson]

As I type this, I can barely press the keys on the keyboard. After carpal tunnel surgery, which was rated as "20" on a pain scale of 1-10 (pre-surgery), the carpal tunnel issue is gone, at the expense of loss of wrist strength (I had a choice, suffer all day long, or suffer when I hold a power tool for 1 minute). I digress....so back to sharpening, this really affects taking a planer blade back to a primary bevel on a water stone. I can maybe get 30 strokes before I have to stop for a few minutes. 3 hours last night on a #5 blade on 150 grit, and I'm still no where near ready to move up to higher grits. I am using a honing guide to hold at proper angle and 6" water stones. I have a PC 6" bench grinder, but the wheels are pretty coarse and I feel like I'd turn my blades into lawnmower blades pretty quickly. Are there wheels I can put on that where I could "maybe" get a good hollow grind without melting the blade? Thanks in advance for any well-intentioned advice about changing how I hold my hands on the stones, but I'm done with hand-grinding, not open to trying other ways. I need to make this work with the assist of a powered grinder then I can take my final honing by hand on the higher grit stones. The wrist pain lasts for days after doing something like this. Or am I going to need to get something like a https://www.amazon.com/Work-Sharp-WS...ood-Sharpener?

[Patrick Whitehorn]

I use a setup modified from Derek Cohen's setup here: http://inthewoodshop.com/WoodworkTec...ningSetUp.html with the difference that I use a full-speed 6" grinder with a CBN wheel from LV. It is a little fussy to set up - each chisel and plane blade has to be checked for angle every time you change - but it is super fast.

I hope your wrists heal quickly - my mother had that when I was a child and I can still remember helping her with everyday activities while she was recovering.

Patrick

[Tim Best]

Hi Thomas,

Glad the operation went well. The thought of resetting a primary bevel on a water stone is an unpleasant one without any added factors.

Honestly, I use the 46 grit blue/grey wheel that came with the grinder. The 46 grit is so aggressive that metal does not have to touch the wheel for very long, reducing the chances of overheating. When I started grinding irons and chisels, I had no experience but I have yet to burn/blue a chisel or plane iron. A good tool rest, light touch, and a slow/variable speed grinder are essential. I have an older Delta variable speed and I leave it at +/- 2000 rpm. It was probably set a little slower in the very beginning. David Weaver has recently done some testing on various wheels. His thoughts/results are posted on Woodcentral. Not to put words in his mouth, but the gist is that the stock wheels are normally pretty good for establishing hollow grind primary bevels. CBN wheels seem to be more fool proof, but also more costly. I grind with my fingers pretty close to the edge of the blade so I can feel the heat build up. I do not even keep a cup of water near the grinder any more.

Tim

[Robert Engel]

Use the Norton white wheels and grind a hollow bevel the. Yourself to go right to stones a d secondary bevel.

Don’t use a fine grit produces too much heat

[Scott Winners]

I guess I will go ahead and play. I use the 120 grit wheel that came with my variable speed 6" grinder. The finer point is to make a wooden block to set up the (factory) rest on the grinder. Just a piece of good straight stock, 3/4 inch thick is plenty, plane one edge flat, mark the angle you want carefully and then rermove that little triangle and dress to the line. Now use the wooden guide on the tool rest to get the angle of the tool rest correct, which is fiddly.

Once the angle is correct I freehand the blade back and forth across the wheel on the tool rest. Keep a square handy to make sure you are keeping the grind perpendicular to the long axis of the blade, and I do use water quenching every pass. Accorss the wheel, quench (slow count to five) check for square, across the whee the other way, quench, slow count to five, check for square, continue.

I do get blue bits with some regularity and have to grind off some more, but _usually_ they are superficial blue bits that didnt burn all the way through. As i get closer and closer to the final angle the wheel face gets closere and closer to the edge of the blade and the extra metal available to carry away heat gets less and less so the risk of a carbon burn gooes up and up. may want to start with a cheap tool, remember the closer you are to finished the higher your risk of losing temper/ burning out carbon.

if I come into big dollars someday I would go to an 8 inch grinder and a CBN, but I have more pressing challenges to handle with the money I do have.

[Andrew Seemann]

I've got a Tormek that I picked up for a steal on clearance years ago. It is definitely faster and less work than hand sharpening, although it does take some pressure from your hands and fingers to use. Most systems where you need to hold a blade against a wheel will be like that though.

I can't imagine doing a primary bevel by hand anymore; that is just painful to think about. I think that would give me carpal tunnel alone.


As an aside, Hand Tool woodworkers often get caught up in Romantic ideas of what "Hand Tool Woodworking" should be. These ideas don't always match our actual circumstances, time availability, and (let's be honest) current physical capabilities. Don't let other people's ideals make your woodworking miserable. There is no shame or disgrace in using electricity for what it was meant for: taking the drudgery out of life. I can't hand plane for as long as I could in my 30s, so I have embraced abrasives again. My body is much happier for it, and I can actually get things done on my wife's schedule.

[Don Dorn]

I have a short read book called sharpening with water stones by Ian Kirby. While I use diamond stones, there is a section on how to use inexpensive items to make a standard grinder a great tool for bevel grinding with very cheap items (less than $5). I've been using it for about 10 years now and have no interest in changing because it works so well - and fast. Then, it's hand honing on via Paul Sellers. Sometimes we go full circle with things to find the easiest method normally works the best.

[Gary Focht]

How long ago was the surgery? My carpal tunnel was gone immediately following surgery, but it did take a few months to return to normal. A year or two later I got De Quervain Syndrome in the same wrist. That was much more painful for me. I was close to surgery for that, but the second shot in the wrist cleared it up and no issues since.

I use a CBN wheel on a half-speed grinder. Works well for me, but I still need to be a bit careful. I prefer it over the blue wheel I had previously tried.

[Thomas Wilson]

I use an old fashioned solution. I have a Makita Wet Grinder 98202 also known as the mud slinger. I have a special holder from Highland Woodworking for chisels and plane blades. The grinder is designed for and I bought it for jointer and planer blades. I have replaced my straight knives with segmented helical heads so the grinder is not needed for that anymore. I keep the Makita for regrinding bevels. The tool rest is really steady and all you have to do to get a square bevel is square the blade to the special holder. I works great. You just have to wear a rubber apron.

https://www.amazon.com/Makita-98202-...11470328&psc=1

[ken hatch]

I've got a Tormek that I picked up for a steal on clearance years ago. It is definitely faster and less work than hand sharpening, although it does take some pressure from your hands and fingers to use. Most systems where you need to hold a blade against a wheel will be like that though.

I can't imagine doing a primary bevel by hand anymore; that is just painful to think about. I think that would give me carpal tunnel alone.


As an aside, Hand Tool woodworkers often get caught up in Romantic ideas of what "Hand Tool Woodworking" should be. These ideas don't always match our actual circumstances, time availability, and (let's be honest) current physical capabilities. Don't let other people's ideals make your woodworking miserable. There is no shame or disgrace in using electricity for what it was meant for: taking the drudgery out of life. I can't hand plane for as long as I could in my 30s, so I have embraced abrasives again. My body is much happier for it, and I can actually get things done on my wife's schedule.

+1 on the Tormek. I have both a Tormek and a low speed 8" grinder with a CBN wheel and the Tormek tool rest. While the Tormek is slower, time to finish is faster because with water cooling there is no need to stop to cool the cutter. BTW, I like the original Tormek stone wheel better than either a CBN or diamond wheel. Kinda the same story, the diamond/CBN may be faster grinding but the time is made up with time saved on the honing/polishing stones.

ken

ken

[Jim Koepke]

This has worked well for me for many years > https://www.leevalley.com/en-us/shop...m?item=05M3101

For a few years multiple blades were worked at a time. This required extra holders.

The finest abrasive is 9µ. For many jobs this may be sharp enough. For others a bit more honing on a finish stone might be prefered.

jtk

[Phil Gaudio]

I think a Tormek might go a long way to solving your problem. It seemed like an expensive gimmick before I used one. Having lived with it for a number of years, I would never be without it.

[Thomas Colson]

How long ago was the surgery? My carpal tunnel was gone immediately following surgery, but it did take a few months to return to normal. A year or two later I got De Quervain Syndrome in the same wrist. That was much more painful for me. I was close to surgery for that, but the second shot in the wrist cleared it up and no issues since.

I use a CBN wheel on a half-speed grinder. Works well for me, but I still need to be a bit careful. I prefer it over the blue wheel I had previously tried.

4-5 years ago. I can now hold onto the steering wheel (had the worst CT the doc said he's ever seen), but lost most of my wrist strength in my dominant hand, about 25% in other. I've adapted my other woodworking techniques, blade sharpening is next. To be honest, I really want to be a neanderthal, but every time I put an iron to stone and suffer the next day, the pair of old Sargeants I got for a steal go back in the cabinet for another 6 months and my neighbors get to hear my jet 15" all day. The practical reason I want to be a neanderthal is I have a pile of reclaimed barn oak that I want to turn into cabinets, and after having worked with it enough already, it's going to be quicker, easier, and waste less wood for me to joint it by hand.

So with the grinder, how are you a)holding it square to the wheel and b)at the desired angle?

[Thomas Colson]

I use an old fashioned solution. I have a Makita Wet Grinder 98202 also known as the mud slinger. I have a special holder from Highland Woodworking for chisels and plane blades. The grinder is designed for and I bought it for jointer and planer blades. I have replaced my straight knives with segmented helical heads so the grinder is not needed for that anymore. I keep the Makita for regrinding bevels. The tool rest is really steady and all you have to do to get a square bevel is square the blade to the special holder. I works great. You just have to wear a rubber apron.

https://www.amazon.com/Makita-98202-...11470328&psc=1

IS this the special holder?
https://www.highlandwoodworking.com/...ndtooljig.aspx

[Thomas Wilson]

IS this the special holder?
https://www.highlandwoodworking.com/...ndtooljig.aspx

Yes, it is.