Sharpening Questions

[Twindaddy813]

Hey guys, I hope I am in the right area for this so if I am not please let me know where I need to be. I am new here and new to pen turning but I am in love! I have a couple of questions about tool sharpening. First off I keep reading about slow speed grinders, some people say this is a must for sharpening while others say you can use any grinder. What is your opinion on this? I have a regular 6" bench grinder I have had forever but I have no problem adding another to my shop if it is really needed. Also, I have seen some wet stone grinders, do they make a huge difference in sharpening? My last question is I have been told to get a Friable Norton grinding wheel, I have looked them up and there are several different grits for the wheels, Is there a universal wheel I can use or do I need to get a few different ones for sharpening? I hope I am not to confusing with these questions, like I said I am very new to this craft and I want to learn as much as possible. I am currently unable to get out in my shop for the next few weeks I just had my second back surgery in the past year, so I figured I will use this time to study up and get things in order so as soon as I can get back at it I will have a lot more knowledge to move forward with. Thank you for any help or information you can give me.

James

 

[monophoto]

James

There are a lot of aspects of turning that are subject to personal opinion. Ultimately, there is no one absolutely correct way to do things - although some people would have you believe that the only way that something can be done is by using THEIR favorite approach.

1. A high-speed grinder will remove metal more quickly than a slow speed grinder. If you are practiced at sharpening tools and have a light hand, a high speed grinder can be used. But some people do prefer slow speed grinders.

2. Wet grinders are nice to have. They aren't necessary.

3. There is a difference between sharpening and grinding. If you are merely interested in removing metal - that's grinding, and is best done with a wheel with fairly low grit - say 36. If you are interested in precise sharpening, then you need a higher grit. How high is a matter of personal opinion. I use an 80 grit wheel, but I've seen recommendations for 64 and 120. The ultimate wheel for sharpening is a CBN wheel - they are available in much higher grit ratings, but also at much higher prices.

There are many ways to sharpen tools. Grinders are a favorite. But other approaches include belt sanders (aka 'linishers' - that's what Robert Sorby use in their shop to sharpen the tools they make), disc sanders, oil stones, Japanese water stones, diamond stones, and according to Capt. Eddie, bricks. Find one you like, and then practice until you are happy with the result you get.

 

[jttheclockman]

Welcome James. Hope you have a fast recovery.

As far as sharpening tools. It probably is the single most important factor in learning to turn. Turning with the wrong tool or dull tool can result in serious injury. With that said there are many ways and methods designed to sharpen tools. There are many machines or apparatus to get this done. Everyone will have their favorites and I am sure you will get some here. The thing is there is no only way just different ways. There is a ton (and i am afraid to say this) of videos on utube and also by many reknown turners. Capt Eddie Castlin has many videos.

As far as tools go a slow speed grinder is a preferred choice because it does not heat the metal as fast. 8" grinder is a better choice because it does not make such a drastic curvature in the tool end. friable wheels such as White ones or blue ones in the 80 grit and 120 grit are preferable. Jigs to hold tools to get consistant grinds is a help. The new craze is CBN wheels. You can read about those. Much more money.

Anyway good luck and hope you get back in the shop soon.

 

[JimB]

James,

When I started I used a 6" grinder with grey wheels and a home made jig. It did an adequate job. I then upgraded to a slow speed 8" with friable wheels. I got a better edge and less heat. I then added the wolverine jigs and got an even better and more consistent edge on all my tools. For me each upgrade made a difference.

I had the opportunity to see a guy from Sorby demo their belt sander sharpening system and I was able to examine the tools. I didn't think they were any sharper than what I am getting now but that is just my opinion. It was a very good system
, I just didn't feel it was better than what I have.

 

[JimB]

I should have mentioned - If I had built a better jig for my first grinder I know I would have gotten a better and more consistent edge on my tools. I was new to turning and I didn't know anything about sharpening so I had a big learning curve.

 

[low_48]

I prefer the 8" grinder, it does not hollow grind as deeply as the 6". Also prefer a 1725 rpm. High speed steel is way more tolerant of grinding heat than carbon steel, but it takes a really light hand with a 3450. Oneway wheels are formulated for 3450. Dressing the wheel is critical. It keeps the steel particles out of the wheel, and reduces heat. 60 grit is a good grit for most work, but prefer 120 for scrapers and skew.

 

[Paul in OKC]

I only have a 6" grinder, had it for about 20 years. I am pretty anull about things and used to fret over sharpening. Read an article by Richard Raffin and he said he just used a plain old grinder and just went to it as needed. No more worrying about it for me. As said above, learning to use a light hand on these they will do fine. Coarse wheel on one side fine on the other.

 

[Edgar]

My only grinder is also an old 6" with a coarse wheel on one side & a wire wheel on the other. Mine's about 30 years old & still going strong. I don't have any jigs - I just free-hand my grinding and use a very light touch.

I actually don't use the grinder very often at all though. I mostly use this set of little diamond hones and only go to the grinder when I need to touch up the shape of the tool.
DMT Dia-Sharp 2.5" Diamond Offset Mini-hone, Kit at Woodcraft.com

These little hones work great for dressing up the edge of my HSS tools and I also use them to dress up the edges of my carbide r2 tools. I generally hit the tools with about 10-15 strokes of each grit whenever I use them

I may not get my tools scary sharp with my technique, but I'm happy with the way it works for me and that's the main thing. As others have noted, there are lots of ways to approach sharpening, so try a few things and see what works best for you.

 

[Akula]

I used a grinder when first starting out. After a few months, it's now only used to get the desired shape and my sharpening is done with diamond hones or stones. My grinder can sit a long time and never see action. Btw, my background is sharpening knives, so I went back to what I was most comfortable using.

 

[Twindaddy813]

Thank you guys so much for all of the information and advice! I think I will give it a shot with my regular old 6" grinder, I did order a couple new wheels for it. I do like the idea of using stones to tough up the edges, I am used to using stones. My father and I have been building knives most of my life so I am comfortable using them. Now I can't wait till I am able to get back in my shop and try everything out!

 

[plantman]

Having been a woodworker and tool collector for over 60 years, I have owned or used about ever type of sharpening device know to man including the sidewalk. As stated by many above, there is no one perfect way to achive a sharp edge. You must first consider several things before you make your choise. How sharp do you want your tools to be ? What tools are you going to sharpen ?? How much money do you want to spend ?? A mirror edge is needed for hand work such as carving, working burls and grainy woods with planes and chisels. It dulls quickly and needs constant touch-ups to remain razor sharp. A sharp tool need not be polished to make a perfect cut on a moving object. It does need a soft touch and controll to do the job it was designed for, and a little touch up now and than to keep it cutting effortlessly. Cost; Buy the best you can afford at the time that will sharpen the largest amount of tools that you own or plan to buy in the near future. Curved tools, or any tool, should to be honed on the back or inside curve after sharpening to remove the micro curl that is left there. As for what to sharpen your tools with. If I am restoring a tool and I need to take out nicks , or I want to change the angle on it, I would begin with a grinding wheel to remove the inperfections or change shapes. Next I would take it to the disk sander to make sure that the end is square to the sides. I now would move over to a large Stainless diamond inpregnated plate to quickly remove any remaining metal. On a plane iron or chisel you may need a jig to set your angle. This can also be done on a belt sander with an angel jig. A slip stone will clean up the back and inside edges. Your ready to turn !! If I want a mirror finish on the hand tool, I will bring out my Japeneese Water stones. Start at 1500 and work my way to 8000. This finish than can be stroped on leather or different powders and oils to make it razor sharp. Carbide tools are best sharpened with diamonds. Over the years all methods have worked fine for me at the time, but as we progress in time and technology, things have become better, faster, more expensive, and less hands on. Sharpness is not something you can buy!!! You have to learn it with practice and time, be it tools or brains !! Jim S