Slow bench grinder OR diamond stone?

[Eric Knapp]

Hello,

One of the things missing in my shop is a way to grind cutting tools quickly. I have a good assortment of water stones for after that but can't deal with an old or new blade very fast. I watched Todd Stock's sharpening videos with the 3 different approaches. I will not be getting a Tormek system anytime soon. I need to stretch my budget farther than that. What's the next choice for this? I have a 1/2" glass plate and I have been using sandpaper but I don't like that approach. It seems like it will be very expensive over time. What do you all use?

Thanks,

-Eric

[Bob Gramann]

I use very fine sandpapers (12 down to 1 micron, if I remember correctly) on a glass plate. When I have an old, ugly tool that needs to start fresh, I use the belt sander with a honing guide to get to fresh material. Then, I go to the glass plate. It's not expensive at all. The sandpapers (PSA from Woodcraft, usually) last a long, long time. Stones eventually wear and have to be trued. When the sandpaper deteriorates, I strip if off with a razor blade and put down a new strip.

I also have a grinder that I use for mower blades, but I don't often use it for my tools. It gets them too hot. I've investigated a Tormek a couple of times, but each time decided that I'm getting a better edge for much less money.

[David King]

You need an 8" grinder, preferably one that runs at 1750 RPM or less instead of the usual 3500. You need a soft aggressive stone that won't get loaded up and you need a dressing tool to keep the wheel square. What you'll find is that you need to go with belt driven grinder arrangement to get the speed down where it won't burn your toolsteel. Whetstones are nice but they are very slow going unless you have a huge one and the stones are easily damaged. Here's a nice vintage craftsman grinder arbor on eBay: http://www.ebay.com/itm/Vintage-Craftsm ... 2031037805
There seem to be some new options, Rikon sells an 8" 1750RPM grinder and Porter Cable makes a variable speed 8" grinder if you can find one.
Baldor does make a 3 phase 8" industrial grinder which you could run at any speed via a VFD, check on Craigslist but figure $1000 for a new one.
Knife grinders use 2" belt sanders and that would be another good option. Whether you use sandpaper of wheels both are expendable and there isn't a free ride.
If you do get a diamond stone think of it as the most expensive way to sharpen anything. Go for the 4 x 10" CMT plate and only use it for final edge dressing. Diamonds aren't cheap and they don't last much longer than sandpaper to be honest.

[Brian Evans]

I use a 1" belt sander that I got decades ago from Lee Valley. I rough with 80 grit, then 600, then establish the micro bevel with 15 micron, then hone with a leather belt and compound.

[Steve Sawyer]

A few years ago I got a blue Norton wheel for my 3450 RPM 6" bench grinder. Normally high-speed bench grinders are horrible for shaping cutting tools for wood as they get too hot and destroy the temper. This stone however is "friable" meaning that it wears quickly, and therefore runs cooler. I put my thumb or finger right behind the edge I'm grinding so I can quench it as soon as I feel any warmth. This is not an ideal solution, but does the job with what I have.

Let me know if you're interested, and I can get you the specifics on this grinding wheel.

[Eric Knapp]

A few years ago I got a blue Norton wheel for my 3450 RPM 6" bench grinder. Normally high-speed bench grinders are horrible for shaping cutting tools for wood as they get too hot and destroy the temper. This stone however is "friable" meaning that it wears quickly, and therefore runs cooler. I put my thumb or finger right behind the edge I'm grinding so I can quench it as soon as I feel any warmth. This is not an ideal solution, but does the job with what I have.

Let me know if you're interested, and I can get you the specifics on this grinding wheel.

Thanks, I don't have anything yet and all the options I'm considering come with what appear to be good white wheels.

-Eric

[Eric Knapp]

You need an 8" grinder, preferably one that runs at 1750 RPM or less instead of the usual 3500. You need a soft aggressive stone that won't get loaded up and you need a dressing tool to keep the wheel square. What you'll find is that you need to go with belt driven grinder arrangement to get the speed down where it won't burn your toolsteel. Whetstones are nice but they are very slow going unless you have a huge one and the stones are easily damaged. Here's a nice vintage craftsman grinder arbor on eBay: http://www.ebay.com/itm/Vintage-Craftsm ... 2031037805
There seem to be some new options, Rikon sells an 8" 1750RPM grinder and Porter Cable makes a variable speed 8" grinder if you can find one.
Baldor does make a 3 phase 8" industrial grinder which you could run at any speed via a VFD, check on Craigslist but figure $1000 for a new one.
Knife grinders use 2" belt sanders and that would be another good option. Whether you use sandpaper of wheels both are expendable and there isn't a free ride.
If you do get a diamond stone think of it as the most expensive way to sharpen anything. Go for the 4 x 10" CMT plate and only use it for final edge dressing. Diamonds aren't cheap and they don't last much longer than sandpaper to be honest.

This is what I was starting to lean towards. It seems like in the long run I will need one so I should not avoid it now. The Rikon looks like a nice lighter-duty one and with the addition of the Veritas grinding jigs it would work for many tasks. The diamond stones looked like a nice non-powered alternative but are more limited. I think this will go on the purchase list and find its way to my shop at some point. Adding tools one at a time over a long period is not ideal and wouldn't work for a pro. That's what I have to do and I'm patient by necessity.

Thanks,

-Eric

[Eric Knapp]

I use very fine sandpapers (12 down to 1 micron, if I remember correctly) on a glass plate. When I have an old, ugly tool that needs to start fresh, I use the belt sander with a honing guide to get to fresh material. Then, I go to the glass plate. It's not expensive at all. The sandpapers (PSA from Woodcraft, usually) last a long, long time. Stones eventually wear and have to be trued. When the sandpaper deteriorates, I strip if off with a razor blade and put down a new strip.

I also have a grinder that I use for mower blades, but I don't often use it for my tools. It gets them too hot. I've investigated a Tormek a couple of times, but each time decided that I'm getting a better edge for much less money.

Thanks. This is what I'm doing for now. Buying sandpaper over a several year period can be very expensive compared to a tool that can be maintained. I read an article about the Scary Sharp system saying it was the cheapest way to get started and the most expensive in the long run. He did the math and it was a lot of money. It's also not as quick, or isn't as good, for many of the things I want to do. For instance, I am interested in that thick StewMac scraper that Al Carruth champions and it works well with a bench grinder. Building my shop slowly...

-Eric

[David King]

If I were dropped on a desert island, a working grinder would be my very first concern.
One nice aspect of the belt drive grinders and sanders is that they spin down a lot faster than a big stationary grinder.
Delta 10" Universal Wet Dry Grinder Model 23-700 is another possibility but the quality of the large stone has dropped over the years. If you can find one from the 70s with the harder wheel you'll be happier. Lots of complaints about how soft the modern wheels are.
I have the model with the horizontal slow wheel and it's a dud though the high speed small wheel that's 2" wide is great and I just pulled the big wheel off because it was so out of balance that it made the whole machine jump around.
Looking at the Porter Cable specs I see the speed range is 2000-3400 RPM, the Rikon would be a better machine all the way around with that fixed 1450 RPM. A wider wheel would be better yet.

[Steve Sawyer]

Since you're starting with a blank sheet of paper, Eric - something else to consider it the Worksharp system. Pretty reasonable to get into, but like Tormek, it's a "system" and you could end up shelling out more for attachments, but if you get the basic setup and one additional glass wheel you're pretty much good to go for most edge tools.

That's my go-to sharpening solution.

[Bob Gramann]

The Carruth scraper is one tool that I do sharpen on the grinding wheel unless I'm going to scrape spruce, in which case, I take it to a fine stone. You do want one of those scrapers. I love mine.

I just bought a 4 or 5 year supply of sandpaper (one full sheet of each grit) for my glass plate for less than $15. It takes me more time to extract the blade from the plane and put it back than it does to hone the edge. Each of us has a favorite way of doing things. I'm not hurt that you don't like my way.

[Eric Knapp]

The Carruth scraper is one tool that I do sharpen on the grinding wheel unless I'm going to scrape spruce, in which case, I take it to a fine stone. You do want one of those scrapers. I love mine.

Thanks, that's good to know. I was wondering what folks thought of it.

I just bought a 4 or 5 year supply of sandpaper (one full sheet of each grit) for my glass plate for less than $15. It takes me more time to extract the blade from the plane and put it back than it does to hone the edge. Each of us has a favorite way of doing things. I'm not hurt that you don't like my way.

I do like it! I have not reached the point where I'm not destroying multiple sheets of sandpaper whenever I try to do anything. I plan on buying the paper you recommend as soon as I can. How do you fix it to the glass?

I still think I will need a grinder, though.

Thanks,

-Eric

[Steve Sawyer]

The Carruth scraper...You do want one of those scrapers. I love mine.

I love scrapers in general, and these look to be a great option. Fairly inexpensive, too!

[Bob Gramann]

The paper I get from Woodcraft has adhesive on the back. It lasts a lot longer if you pull the edge to you rather than push. Every now and then, I get the temptation to push/pull back and forth, back and forth. That usually rewards me with a tear.

[Eric Knapp]

I just bought a 4 or 5 year supply of sandpaper (one full sheet of each grit) for my glass plate for less than $15. It takes me more time to extract the blade from the plane and put it back than it does to hone the edge.

Do you have a link and/or full name for the stuff you get? The Woodcraft website is not being very cooperative and on Amazon there are too many options and most of them are for full cases.

Thanks,

-Eric

[Bob Gramann]

Search Woodcraft for "PSA lapping film." Use something coarser glued on the glass to establish the 25 degree angle on your chisels and plane blades (and to level the back surfaces, if necessary). Then use these papers to polish the backs and to establish and maintain the 30 degree microbevel. When I'm being smart, I start a session with an edge by touching it up on these papers on glass. That takes a couple of seconds. When I'm being dumb, I skip the touch up and then go back and do it anyway when the plane doesn't joint a top in a few passes.

(edited: changed "paper" to "film")

[Steve Sawyer]

I find that if you use the wet-or-dry and wet it, the water sticks it to the glass well enough to get the job done.

Also, I just laid in a supply of sandpaper from Peachtree. They have packs of 50, but assortments of 10 each of a range of grits. I was low on everything so I got two assortments each of both wet-or-dry in the finer grits and the Mirka basecut in the coarser grits, so I have a minimum of 20 sheets of each grit in the stash.

[Eric Knapp]

Search Woodcraft for "PSA lapping film."

Thanks, that works.

Use something coarser glued on the glass to establish the 25 degree angle on your chisels and plane blades (and to level the back surfaces, if necessary). Then use these papers to polish the backs and to establish and maintain the 30 degree microbevel. When I'm being smart, I start a session with an edge by touching it up on these papers on glass. That takes a couple of seconds. When I'm being dumb, I skip the touch up and then go back and do it anyway when the plane doesn't joint a top in a few passes.

(edited: changed "paper" to "film")

I already have a set of Japanese water stones I'm very experienced with and can get a great edge. I will experiment with the lapping film since it's not very expensive and I like learning new things. What I'm missing is an efficient way to do the coarser grinding you mention here. For instance, making a plane blade square takes too long without a grinder.

-Eric

[Eric Knapp]

I find that if you use the wet-or-dry and wet it, the water sticks it to the glass well enough to get the job done.

Also, I just laid in a supply of sandpaper from Peachtree. They have packs of 50, but assortments of 10 each of a range of grits. I was low on everything so I got two assortments each of both wet-or-dry in the finer grits and the Mirka basecut in the coarser grits, so I have a minimum of 20 sheets of each grit in the stash.

I'm trying to stop using wet-or-dry paper, that's what gets expensive over time. I have water stones and I'm looking for a coarse grinding option that is more efficient than what I have.

-Eric

[Bob Gramann]

Squaring a blade doesn't happen often. I use the belt sander because it's easy and it's there. That's where I'll make the 25 degree angle as well if I'm already there. Just watch out for heat.