secondary bevels, bench chisels
I tend to overthink things (or do I?), and my current obsession is secondary bevels on bevel-edge bench chisels. Assuming you think they are a good idea (if not, please have at it),
1A) how far from the front edge should the secondary bevel extend? (1/16″?) Does it matter all that much?
1B) I assume that after many (many) honings, the secondary bevel will become the primary bevel. At what point do you decide to re-establish the primary bevel?
2) I don’t have a bench grinder. If I bite the bullet and get a slow-speed bench grinder + accessories, will I regret it? I understand this is a hard question — let’s say I’m an increasingly-serious hobbyist and I’ve got 20-25 years ahead of me. I guess I’m also wondering how slow and painful it is to re-establish primary bevels using sandpaper or other technique(s) (I use water stones for sharpening and am quite happy with that). For something like this I wouldn’t go top-shelf (e.g. Tormek), but wouldn’t go cheap either. I’m guessing $300 (?) would set me up nicely.
Hi, I think your answer is in your question 1B. When your secondary bevel starts to get too big it will take you longer to sharpen because you are taking off more steel. Re-establish the primary bevel but leave a little of your secondary bevel so as not to waste steel or time. I use a Tormek but similar systems are now available. Don't overthink it and you will be ok.
I don't have a bench grinder either. I just sharpen everything to 30 degrees (diamond stones and a honing guide) and don't worry about secondary bevels. I've been woodworking for 4 years now with just hand tools and I've been happy with the results. I can sharpen a chisel or plane iron in under 5 minutes this way.
Me too. :-)
I don't want a bench grinder as I'd worry about over-heating. Just once and a blade's ruined. I did have Tormek but sold it because it was too slow and messy to set up then clean. But having moved (workshop and to more hand tool woodworking) a better sharpening regime became a necessity.
All my reading and subsequent experience suggests a micro-bevel on a primary bevel is the way to go for quick and easy sharpening. ALl my blades are set up like this.
Another technique is to buy tools and blades that come with their backs already dead flat. I hate spending hours flattening cupped or twisted chisel backs and have rejected a new chisel rather than put it right. Lie-Nielsen, Veritas and some other manufacturers now supply their tools and blades with dead-flat lapped backs; often good primary bevels too. Some others are banana-shaped!
With plane blades (not chisels) you can also use the ruler-trick to avoid lots of blade back flattening by putting a tiny back-bevel of just 1 degree or so on the edge once the back has deeper scratches polished out - but just near that edge.
If you're careful not to make too big a secondary bevel (or back-bevel) they stay small and sharp through many honings. Unless you work a blade all day or in rock-hard Ozzie timbers and similar, you can keep a decent blade sharp for a long time with just honing. No more aggressive sharpening needed for some time.
I did need to put an initial bevel on some less expensive chisel blades I had when going more hand tool. I found a 140 grit diamond stone of good quality (mono-crystalline) did the job in reasonable time even with a wider blade. A honing guide was a necessity, though, to avoid the multi-faceted bevel. :-) It then takes little time to reduce the 140 grit scratches on that primary bevel to a condition fit to take a micro-bevel of a degree or two steeper, with 400 grit and maybe a bit of 10o0 grit.
Once the back is flat, the main bevel sorted and the micro bevel(s) established, it requires little subsequent work to keep the blades sharp. I expect it to be years before I'd need to re-make a primary bevel. But I'm an amateur applying relatively few hours/month work to my blades, although I do use lots of hardwoods including the nastier exotics that are cruel to blades.
Final thought - some blade metals wear better than others. Veritas PM-V11 is getting a very good reputation for resilience, for example, even though it sharpens as easily as A2. D2 is very resilient but hard to sharpen, by all accounts.
Here's another option for grinding your bevel. I use a hand cranked grinder, which doesn't turn fast enough to over heat your metal. Mine is made by Genko (made in Germany) and has a geared crank that allows easy cranking at speed. I use a home made tool rest with an adjustable wedge to control the angle. It works great, is not expensive, and doesn't take up much space. I don't know if this model/brand is still available.
1 A & B
-- Don't worry about the distance, you just need to worry about the angle. Typical rule of thumb is to grind at 25, hone the bevel at 30 or somewhere thereabouts in that ballpark. You'll eventually get to the point where you'll be able to notice it's taking longer than you'd like to get that secondary bevel through honing. When you get to that point that's where you go back to whatever method you choose to reestablish your primary bevel. Then you're back in business. Depending on how much you use and abuse your tools you may not have to regrind for quite some time.
2. No, you won't regret it.
I have a slowspeed bench grinder with the white wheel. To go with that I got the Veritas grinding tool rest and jig. There is no bench grinder out there that will come with an adequate tool rest so upgrading to the Veritas or Wolverine or something similar is a necessity.
You can do all this with a honing guide and coarse stones (diamond stone, sandpaper on glass/granite, etc etc) to reestablish a primary bevel but it's gonna take some time.
Now, I don't use my bench grinder very often but when I do use it, boy am I glad to have it. You can knock back to reestablish a primary bevel pretty quickly and get to honing the secondary bevel in no time. To reestablish your bevel by hand doesn't necessarily take that long, but when you've got a bunch of chisels and some plane irons those time savings are exponential.
My advice would be to go for the bench grinder. Get it set up with the right wheels (go through a woodcraft or anyone else that deals in woodworking products and you'll be able to get it with the wheels already on it) and get yourself a quality grinding jig. I would guess that you would be able to get set up for under $200.
Then get yourself some sharpening stones (go up to at least 8000) and you're in business my friend. Up to you whether or not you want to get a honing guide (if you do, don't skrimp out, get a good one).
Anything you do the right you will not regret!
Along with the others here, I will chime in with my 2 cents worth on secondary bevels. My advice here is based on about 40 years of furniture-making experience, and about 30 years of teaching students. I've taught a LOT of people how to get keen edges on their tools.
Secondary bevels are popular for a couple of reasons. The first one, already mentioned in other posts here, is speed. Since the secondary bevel is much smaller than the primary bevel it takes far less time to hone.
The second reason is edge life. Since the secondary bevel is at a steeper angle than the primary bevel (30 degree secondary vs. 25 degree primary, for example) the edge life is somewhat longer. This is due to the small amount of additional steel behind the cutting edge, offering a bit more edge support.
As you approach the point where the primary bevel and the secondary bevel are the same size it is time to reestablish the primary bevel. Of course you could also take this step any time you feel you're spending too much time honing.
You'll reestablish the primary bevel in one of two ways: using a grinder or by hand on some flat abrasive. Contrary to what you're reading in these replies, it most certainly IS possible to blue the steel on a hand-cranked grinder. It's also easy to learn to not do this - on a hand-cranked grinder, or an electric one. Woodworkers all over the world grind their tools safely and without bluing. Also, it is NOT correct that once you've blued the steel, the tool is ruined. Yes, the temper is drawn out of the steel in the blued area plus a little beyond - but the simple solution to this situation is to carefully grind past the blued area. I know it's counter-intuitive that the solution to poor grinding is more grinding. But that's it. Your tool is not ruined.
I will offer you a few recommendations - take them for what they're worth.
First: if you've never taken a sharpening class from a professional woodworker, do it. Pros depend on sharp tools, and want the keen edge with a minimum of wasted time. Most pros I know, myself included, use some sort of grinder to re-establish the primary bevel for one simple reason: it is faster than doing it by hand.
Second, don't scrimp on your sharpening setup. Buy good stones, and maintain them. Keep them dead flat, and keep them in water if you have water stones. Incidentally, the initially higher cost of a good set of stones will be offset many times over by not having to replace them two or three times during your 25 years of future woodworking.
Finally, buy good tools with good steel. High quality tools hold an edge much longer, which means more time woodworking, less time sharpening, and longer tool life.
If you want to read about how I teach sharpening in my classes, you can have a look at a few posts on my blog starting with this one:
Good luck and happy sharpening!!
Personally, I usually use diamond stones and a high speed grinder. Just use a white wheel with a crown on it. The crown limits the amount of the tool being ground at any one time.
It's a bit of a myth that the chisel is ruined if you blue it or burn it. Only that little bit is softened and generally the damage is literally skin deep. With a decent wheel and a crown on the wheel this is not an issue anyway.
$300 US is probably on the skinny side but not too far off the money.
For a grinder you will need:
1. Grinder - I'd go for an 8 inch right from the start.
https://woodturnerswonders.com/collections/rikon-grinders/products/rikon-1-hp-grinder-full-dress-with-guards is $275 including postage.
2. Proper tool rest - you need something like https://www.woodcraft.com/products/veritas-grinder-tool-rest?display_currency=USD - about USD 60. The tool rests that come with a grinder are for throwing away. They're ok for felling axes and for grinding raw stock to shape but not for woodworking tools.
3. Proper diamond wheel dresser - not expensive but essential - about USD 10
4. White wheel (may come with the Rikon but allow $20-40 (on runout at Woodcraft now at the lower price)
5. PPE - well-fitting goggles are essential
6. If you turn, give serious consideration to a CBN wheel (useless for chisels) and the amazing Kodiak sharpening system from Woodturners Wonders. Horribly expensive but worth it.
The reason for this pick is that it is really easy to achieve good results, the radius effect is a little less than with a 6 inch machine AND you have the basis for a really good polishing and turning tool sharpening station if you decide to go that way in the future. If you shop around, buy local and don't pay postage you'll only come in a whisker over your $300 budget AND you'll have a decent setup that will last the rest of your life.
As for 1A - it makes no difference and 1B - when you get fed up honing a very long bevel.
If you don't have any sharpening stones, I'd go for those first though - it will be a LONG time before you need to re-establish the primary bevel.
thanks everyone for the great feedback and advice. I've learned some things and also learned that I'm on the right track. When I became more serious 6-9 months ago (and realized this wasn't just a phase), I spent a decent chunk of time learning about plane blade sharpening (including one of the Charlesworth dvd's...good lessons in sharpening and patience). I also decided to buy the best as I understand it, so I have four LN planes and 3 chisels, a Veritas router plane and a few Veritas saws (dovetail, carcass and tenon) that I got during their "factory seconds" black Friday deal last fall. As a relative newbie, going big on planes made sense to me mostly because now I know when something gets screwed up, it's almost certainly my technique or tuning and not the plane itself. This is great comfort to me (also comforting is that LN planes hold their value well and I could get back lots of the investment if I wanted to).
I suspect I don't really need a grinder for these. On the other side though, I bought a mid-19th century skew rabbet plane for $40, mostly because I share the same name as the toolmaker and it was made in Vermont (I'm a New Englander). I cleaned that blade up with stones as best I could, and it actually works pretty well :)
Woodcraft has a Rikon 8" on sale for $109 and the Veritas grinding set (tool rest + guide) is $69 at Lee Valley so it looks like I can get in around $200 (currently use the MK ii for plane blades and chisels). Maybe I'll buy some old planes and/or chisels and see what I can do. It's all good :)
p.s. Lee Valley has free shipping on orders $40+ through Feb. 25
Like you, I am known for overthinking things, just ask the wife.
I have been hand sharpening for 30 years and will continue. I recently picked up the Jet version of the Tormek and tried it for a month, and it has a new home. It was simply too slow and certainly messy.
After years of overthinking and overworrying, I simply use the old guide, granite tile and paper method. Sometimes I put a very small microbevel on a chisel or plane blade, but I am generally happy with the simple approach. I find it works just fine for me, on dovetails, etc.
As i push toward 80, I'm migrating to the simple approaches on everything.
Hollow grinding is an excellent, time saving way to go, as you are going straight to a final edge when you hone. Regardless, IMO a bench grinder is a necessary part of a ww'ing sharpening setup. There will be times when you need to repair damaged edge, or regrind a special purpose edge, etc.
Even with a hollow ground bevel, I usually end up honing a secondary bevel anyway which is really a "micro bevel" as such barely visible to the naked eye.
As for slow speed grinders, its a matter of personal choice and expense, but for me, I could never justify the cost of a Tormek.
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