Square chisel bevels and coplanarity

A few thoughts...

Bryan in Broad Ripple, IN

>You bring up some interesting issues that I've been grappeling with for years. The issues that you mention are, in large part, why I have migrated to the free-hand school of sharpening.

First of all, whether or not the front and back of the chisles are parallel is NOT necessarily a function of the quality. All of my nicest and most used chisels have a pronouned wedge shape to them. Further, the sides are not parallel either, but taper slightly towards the socket. This includes my Stanley 750's, Witherbys, Greenless, Pextos, Van Camps, etc. In fact, if you look at the new LN's (very high quality) you'll see the same general shape.

I've found that in my chisel arsenal, it's the lesser quality, newer chisels, that have parallel sides, and parallel fronts and backs.

What this means is that the conventional sharpening jigs (I don't know about the LV Mk II) do not work very well with them. In addition, if you have butt chisels with a blade length less than 2.5 inches or so, you might as well forget tring to use the older style jigs to sharpen them. It's just an exercise in futility and frustration.

That is why I free-hand sharpen. Once you learn how, there is not much in the way of funky shapes that will give you much trouble. Even 1/8" paring chisels are not a problem for me.

As far as establishing the bevel angles, I establish the angle off of the back of the chisel. I use a 1" belt sander, and establish the bevel angle off of the BACK by positioning the back of the chisel on the tool rest. I just set the angel between the belt platten and the tool rest equal to the bevel angle, and grind away.

It's really pretty simple, and quite fool proof. However, by doing this, you have to give up hollow grinding as the bevel is ground flat.

It works great for me!

-Bryan

Re: Square chisel bevels and coplanarity

Chris Knight

>Dave,

The LV Mark II will handle this situation - it registers off the back of the blade. That aspect is one of the jig's greatest features in my view,

Chris

Re: Square chisel bevels and coplanarity

paul womack

> [chisels]...did not have their tops coplanar with their bottoms

Yep. It is clear that "ideal" jigs should alway reference from the cutting surface (AKA back) for this reason.

In particular, older mortice chisels often have rather rounded top sides, and some small bevel edged chisels have almost NO top side. Many "strong" old chisels are tapered in thickness along their length, which mean the top isn't coplanar in length, even if it is in width.

Sadly, it's harder to make a jig like like this, so many reference of the top side. Since many chisels do have coplanar tops and bottoms these jigs find a niche in the market place, and are often simple and convenient to use.

There is no "ultimate" sharpening jig.

BugBear

Experimentation.

Dave (Arlington, VA)

>Hi Bryan -

Thank you for your post. I bought these chisels, in part, (with the exception of the Sampson (Union Hardware) which is a firmer) to have some chisels I would might use to practice my free hand sharpening... expecially the 1 1/4 Fulton. So I have been flattening their backs and have only recently begun to think about putting on a bevel - only to find that all have non-coplanar tops and bottoms.

If I understand your comment about your 1" grinder, I assume it must rotate clockwise for you to be able to register the bottom against your grinder rest and safely grind the bevel. Am I right? My grinder is a standard counterclockwise rotating grinder and it is hard for me to think how I could register the bottom of the chisel against the tool rest and safely grind away....though perhaps I am mistaken about this.

In any case, I do want to continue to work on my free hand sharpening, but I am concerned that I don't get enough shop time to keep the skill honed, as it were.

Again, thanks for your post.

Regards -

Dave

Re: Square chisel bevels and coplanarity

Dave (Arlington, VA)

>Thanks, Chris. That's good to know just in case my frustration level gets too high. Right now I have two sharpeing jigs, and I am reluctant to invest in another... and I am more and more interested in learning to free-hand anyway.

Still I appreciate your post and knowing that the MK II is out there if this free-hand effort gets the best of me.

Regards -

Dave

Busting my bubble...

Dave (Arlington, VA)

>Hi Bugbear -

Say it ain't so.... no ultimate sharpening jig. Still I appreciate the confirmation that it's not just me... or, at least, it's not just me this time.

Also my heartfelt condolences on the cowardly attacks in London. Our prayers are with you and those who have suffered and are mourning.

Regards -

Dave

Re: Square chisel bevels and coplanarity

Joel

>take a look at the kell guide - it references off the sides with plastic washer to take up any inconsistencies. You can easily measure angle by distance from the wheels as it can be used either top or bottom referencing.

note: If i was actually planning on using a guide the kell would be it - but i think learning to properly free hand sharpen has so many advantages I've never actually felt the need for a guide.

nope...

Bryan in Broad Ripple, IN

>Dave,

I use a 1" belt sander, not a grinder. The motor on the sander is reversible, so I can control the direction of the belt rotation. Since the platten on the sander is flat, the resulting bevel is flat as well. Hence, no hollow grinding.

Good Luck.

-Bryan

Got it. Thanks!

Dave (Arlington, VA)

>

Re: Square chisel bevels and coplanarity

Dave (Arlington, VA)

>Thanks, Joel.

I guess I was hoping that: (1) I was doing something stupid that could be corrected, or (2) there might be a work-around for this problem with one of most common sharpening jigs. The Krell does look interesting, but I'm not real excited about acquiring yet another sharpening jig when my - long-term - aspiration is to learn to free hand.

Thanks for posting.

Regards -

Dave

Sorry. Kell, not Krell

Dave (Arlington, VA)

>

Re: Square chisel bevels and coplanarity *LINK*

joel

>Then absolutely go ahead and learn to free hand sharpen. Do it now, why wait. It's really simple - you just need a repeatible technique and a little practice.

Once learned it's like riding a bicycle - you just don't fall off. The main reason I see that people use jigs is that they haven't been exposed to a reliable free hand method and then a little practice (I know not everyone will agree with me there). but there are so many advantages it's worth the hour or so to learn. Here is a link to a series of lessons by the guy who taught me. I don't know of a more detailed examination and explaination of how to free hand sharpen available in any media. (I know it's my site but I can't find anything anywhere that spends that amount of ink on just learning to hold a chisel on a stone consistently. )


Guide to free hand sharpening by Maurcie Fraser

Re: Square chisel bevels and coplanarity

Dave (Arlington, VA)

>Hi Joel -

Thanks for your post. I have seen the write-up you reference on your website. Thanks for hosting that. It is very helpful and I can recommend it to others. It has served as much of the basis for my experiments - so far - in free hand sharpening.

Regards -

Dave

Re: Square chisel bevels and coplanarity

paul womack

>The Kell does look interesting

The Kell is guaranteed to make a hollow in your stone.

BugBear