Making the Primary Bevel Without a Grinder?

[David Weaver]

Good morning.

I've been trying to avoid buying a grinder because I don't like hollow grinds, and I've been re-doing the primary bevels on my chisels and plane irons with either sand paper or a 220 grit norton stone. The norton stone has been a big disappointment for anything other than flattening backs, and even at that, it might not be that useful. It hollows out too quickly, and doesn't cut as fast as I thought.

The best thing I've been able to figure out so far is to use a long piece of plate glass and glue or clamp down a piece of scrap 60 or 80 grit from Klingspor and then drop some 60/90 grit silicon carbide grit onto the paper as soon as it starts to not cut.

That works well when it's one plane iron or one chisel, but I have about a half dozen old forged framing and mortise chisels that need the primary done again because they were abused.

Has anyone come up with a better system that isn't going to require a hollow grind?

I don't want to be buying that device that uses sandpaper (worksharp or something) because I don't want to have to pay for the sandpaper on it, and I already flatten, apply microbevels, etc. freehand with stones, and I'm very satisfied with the speed and results of that and don't want to use some device. I'm very satisfied with the stones for everything other than recreating the primary on an old used chisel that someone has decided to use to bang on nails or screws.

What do you guys do? Should I put a belt sander in a bench slave and turn it on low speed?

I should add I'm using the basic $15 honing guide to set the primary bevel - I do the touch-up sharpening by freehand, but not primaries (does anyone do that?).

[Derek Cohen]

David

The alternative to a hollow grind is a microbevel on a flat grind. The angle of the flat grind is not critical and it is more important to get it fairly even/level.

The quickest way to achieve this is on a belt sander with 120/240 grit. Here is the jig I designed (published in FWW):

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/BladeHolder1.jpg

This can also be done using your $15 honing guide ...

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Grindingachisel1.jpg

One you have the primary bevel, then just add a microbevel of your choice.

Regards from Perth

Derek

[David Weaver]

Derek - right on the first parts. I've been using that method (flat grind and and microbevels), per a David Charlesworth video. He doesn't explain grinding the primary bevel, though.

Does what you're doing there create any significant heat issues? I guess it would be fairly easy to quench it often to avoid any problems, but the belt speed probably doesn't come close to approaching a grinding wheel. My interest in keeping the primary bevel close to 25 degrees (or within a few degrees on the fat side) on most chisels and planes is related only to how much easier it is to put a microbevel on a blade with that primary bevel, and still have a nice amount of relief (10 degrees?) in a plane with a 45 degree bedding angle.

Mortise and framing chisels get the 30 degree primary treatment, though. The going is slow doing it by hand on a damaged chisel.

All of this in mind with that I'm still a relative beginner and just would like to do things right the first time.

but also in consideration that I have 6 badly beaten up framing and mortise chisels that someone decided to use to pound nails, etc, and perfect

Your picture and advice is much appreciated.

[Derek Cohen]

Hi David

For flat bevels my choice of weapon is the belt sander. It runs at half the speed of a grinder, and it runs fairly cool as the length of the belt dissipates the heat quite quickly. You can burn an edge, but it is a relatively safe way of grinding.

My jig is a variation of the Tormek for a belt sander. There are write ups at:

Mk I: http://www.woodworkforums.ubeaut.com.au/showthread.php?t=14908&page=1&pp=15

Mk II: http://www.woodworkforums.ubeaut.com.au/showthread.php?t=16156

You can set up the grinding angle very accurately. Here is how I do it (plane blade in example):

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Combined5and6.jpg

You can even do curves, as with a scrub plane blade ...

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Bladeradiustemplatesandgrinding.jpg

Here are three really thick mortice chisel blades where the primary bevels were ground to 20 degrees (with a secondary of 35 degrees). This required the removal of a lot of steel as the original primary bevels were 30 degrees. Grind and quench in water. The belt sander gets warm but, used sensibly, never in danger of getting too hot.

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Morticechiselrestoration1.jpg

Regards from Perth

Derek

[David Weaver]

Fantastic, esp. with regard to the scrub blades. Thanks for the advice and the pictures.

[John Schreiber]

Yep, belt sander is my recommendation too. It is possible to burn a blade on a belt sander, but it's not a problem if you are careful. Not like a grinder where it happens even if I am careful.

[Pete Bradley]

I use a 6X48 belt sander. 1000s of other household uses too!

Pete

[David Gilbert]

I don't like grinders either. Maybe because mine isn't set up correctly and maybe because I have never practiced on it.

I use the Scary Sharp system and really like it. I use Brent Beach's system that can be seen at http://www3.telus.net/BrentBeach/ (http://www3.telus.net/BrentBeach/) . Brent describes building a small jig that holds the plane blade or chisel and also has all the calculations to figure out the angle of all your bevels. To generate the primary bevel I use a DMT very course/course diamond stone. I routed out some 3/4-inch MDF that holds the stone with a couple of wedges and then use my sharpening jig on either end and on the side. The diamond stones cut more slowly than a grinder or a sander but they also won't over heat the blade. So far I haven't worn out the diamond stone and it certainly generates a flat bevel with a square edge. After I have the primary bevel set, I move on to my glass mounted sandpapers. The nice thing about Brett's system is that I don't need to remount the blade in the jig to get all the secondary bevels. It takes only a few minutes to do the final sharpening for each blade and they are really sharp.

Cheers,
Dave

[George Springer]

I'll second the DMT's for primary bevel but I've also used a belt sander at times. Either method works well, it's just a time thing. The DMT's are hard to beat but so is a Tormek or Jet wet sharpener.

GS

[Larry Williams]

Good morning.

I've been trying to avoid buying a grinder because I don't like hollow grinds...

Can you expand on why you don't like hollow ground bevels?

[David Gilbert]

Maybe the reason I don't like them is that I haven't really tried them. In Brent Beach's link (see my link above) he goes into more detail than I can imagine about the difficulty in setting the correct angle. There is also the issue of the grinder diameter with larger being better than smaller. He really likes the belt sander systems and spends a lot of time describing them. I like the ability to know where I am for angles and such and with a hollow grind it’s not always that straight-forward to know where you are. I guess that I just like the flat primary bevel.

Cheers,
Dave

[Bob Smalser]

I guess that I just like the flat primary bevel.

Cheers,
Dave

No worries, they both work fine.

I don't do hollow grinds when I can avoid them because there is less steel behind the cutting edge. It's easy to burn while grinding and remove more steel than you absolutely need to in honing...and when I accidentally kick one off the scaffold, it is more likely to chip badly.

[David Weaver]

Bob - that's the reason I don't want to do it. I want to be able to pick my edge geometry simply. I realize that in regular use, the times when you'll break something out with a properly done hollow grind are few, but it's still a compromise in terms of edge strength vs. relief angle or cutting angle.

I also don't want to have to worry about dressing stones and not running the temper out of a blade. That would create an enormous nuisance right away.

[lowell holmes]

I've used a flat mill bastard file to file the chisel square and put the bevel on it. You can use the file like it is a stone. Put the file on a bench in front of you, the file being cross ways. Hold the chisel with bevel flat on the file with your right hand and pull the chisel across the file with your left hand. Don't move your arms, but rock to the side with your body. The Norton DVD shows this technique and Mike Dunbar showed it in a recent article (the rocking side ways, not the file). The idea of using a file came out of the book Antique Doctor.
Finish up withscary sharp, diamond hones, water stones or what ever. The Norton DVD shows how to add the secondary bevel by hand.

[Derek Cohen]

Maybe the reason I don't like them is that I haven't really tried them. In Brent Beach's link (see my link above) he goes into more detail than I can imagine about the difficulty in setting the correct angle. There is also the issue of the grinder diameter with larger being better than smaller. He really likes the belt sander systems and spends a lot of time describing them. I like the ability to know where I am for angles and such and with a hollow grind it’s not always that straight-forward to know where you are. I guess that I just like the flat primary bevel.

Cheers,
Dave

Dave

From my post above you will realise that I am a supporter of the belt sander. However, what you may not be aware is that I believe in "horses for courses" and use a grinder just as often. Both of these are simply to prepare the bevel face for the appropriate microbevel, which constitutes the honing/sharping/smoothing process.

What I particularly like about hollow grinding blades is that this makes the process of freehand honing a relative doddle. It is far easier to balance a thin metal strip on two points than on one. You can feel when the bevel face is locked onto both of the side of the hollow. Not so easy with a single, flat grind. There is a tendency to rock a flat side and create a rounded face. Where is the accuracy of the bevel angle then?!

Obtaining an accurate bevel angle with a grinder is fairly easy if you use the Tormek angle setter as I do, or a similar jig.

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Dovetailchiseljig-settingupgrinder.jpg

But the fact is, if you are using such set ups on bevel down planes, that the angle is not critical at all. It is more important that you get repeatability.

I prefer to hollow grind all bench planes that are bevel down, the bevel up planes with bevels of 20 and 30 degrees, and Western chisels. My grinder has a 6" wheel. To date this has not been a problem - that is, I have not experienced/seen any weakness in the edge as a result of a deeper/steeper hollow. Nevertheless, if I were to buy another grinder now, it would be a 8" dry grinder (speed is immaterial as far as I am concerned - a gentle touch is needed which ever speed you get) or a Tormek-type grinder (note that these are grinders not sharpeners). The down side of the 6" wheel is that it removes more steel. The up side is that you do not need to grind the blade as often.

I will use a flat grind with micro bevel on Japanese chisels, mortice chisels, precision planes such as shoulder planes, and high angled bevel up planes.

Regards from Perth

Derek

[David Weaver]

Derek - in this process, I gather that the hollow grind is or is almost where your final microbevel would've been had you flat ground to 25 degrees (i.e., something like 10 degrees of relief from the the surface of the workpiece?).

Or do you just grind to 25 degrees or so and call it good enough and just have a larger relief angle from the primary?

For whatever reason, I don't have any trouble putting a microbevel on a flat ground blade. The only thing I can think of as a drawback to it is that sometimes I have to go through the process twice instead of once (on a polishing stone) to touch up the thing if I didn't get the angle quite right the first time. On a 10,000 stone, that screwup doesn't cost much material. I set up the whole process with my thumb as a gauge (the tip touches a stone once I have it set on a place on the iron) using a child's protractor, and my thumb doesn't move until I'm turning the iron over to the back to remove the wire edge. The thumb tip part makes it so that I I can't use that technique on a belt sander, and I don't like the way that the $15 honing guide can rock. Great for putting camber on a blade, but may make it more difficult than it needs to be to sand off a square primary bevel.