Friday, August 4, 2017

A Tale of Two Chisels

While chopping mortises for the plant stands, I thought I'd use a mortise chisel I came across at a garage sale not too long ago.  Prior to that my, mortising chisel was my standard Irwin bench chisel.
1/4" Irwin bench chisel and ~1/4" Ulmia mortising chisel
These two chisels are very different from each other.  Aside from the obvious difference in length, the Ulmia has a much thicker blade, a shaped wooden handle (as opposed to the plastic handled Irwin) and the blade has a tang while the Irwin is a socket chisel.  Both bevels are ground to about 25°, with a microbevel of about 30°.
The edge profiles
The difference in length is quite significant.
That's one long chisel
The length of the mortise chisel comes in handy when it comes to keeping the chisel vertical by sighting down the piece being mortised.
Much easier to tell if you're off vertical
Can still use this method with the Irwin,
but any deviation from vertical is not as pronounced
I timed a few mortises, using either chisel in turn.  They were both freshly sharpened.  There really wasn't any difference in how long it took to chop a mortise.  But look at the cutting edge of the Ulmia after just a few mortises.
See the white reflection at the end?
That's one dull chisel
I don't know about these Ulmia chisels.  Maybe the steel is bogus.  Maybe there was a hard spot in the oak that I mortised that was tough on the edge.  Maybe it was user error.

I really like the advantage that the length gives.  But if the steel is not going to hold up to the stresses of mortising, it might not be worth it.

FLASH!  This just in!  Thought I was done with this post, but just today I received in the mail a mortise chisel.  I had no idea this was coming my way.  Ralph, I don't know what to say, but thanks.  I owe you big time for this.
It's a 3/8" (or a tad over 3/8") "pig-sticker" from I. Sorby!!
Holy mackerel, this thing is beefy!  Look at that handle.  I think it'll be able to take a bit of pounding.  And here it is compared to the other two chisels.
The Ulmia chisel looks like a skinny runt by comparison
All I can say is, wow!  Can't wait to sharpen this chisel up and try it out next time I need a 3/8" mortise.

Maybe I should have entitled this post "A Tale of Three Chisels".


  1. I have that same Sorby 3/8 chisel! Well I have a feeling mine blade is longer, and the handle is bigger. My blade is 7 1/4 long. The handle is wider than the tang. Yours seems about the same. I have more success with a mortise chisel then a bench chisel. I have an easier time keeping it straight.

    1. David, thanks for the comments. After I get this chisel sharpened up I'll have to cut a practice mortise or two. Very interested in seeing how easy it is to keep vertical and how well it chops.

    2. Just a quick thought on using EOBMC aka pig stickers. While they are very robust and can take a licking, I have much better results not utilizing that robustness. Tap, tap, leaver, tap, tap, leaver. Repeat until everything that doesn't look like a mortise is removed.

      Going Conan on 'em slows the process and wears you out.

      Ralph is a generous man in many ways, the world is a better place because of folks like him.


    3. Ken, thanks for the tips on using the mortise chisel - I'll keep that in mind. BTW, what's the EOB in EOBMC? (Guessing the MC is mortise chisel)

  2. We all get a gift from Ralph with the tireless work he puts into his blogs. Thank you

    1. So true, Marshal. Somehow he gets a lot of woodworking done by 5:00 p.m. - and that's after working a full day! Then finds time to write about it, too! That guy has got a lot of energy.

  3. EOBMC...English Oval Boister Mortise chisel. Easier just to call 'em pig stickers :-).


  4. oooh you are in for a treat using a pigsticker is a lot of fun. Now that is a mortise chisel!! You will quickly appreciate all the little details about this form. The handle shape let you know which way the edge is without looking, the tapers allow the chisel to stay registered but not get stuck, its thick blade allow effortless prying without fears of bending or snapping the blade and etc. It is in my humble opinion the perfect mortise chisel. And truth be known, you only need one, either 1/4 or 5/16 for most work in furniture.
    Ralph you are the man.. :-)

    Bob, pounding on my first EOBMC since 2003

  5. One last thing, that Irwin chisel is not a "true" socket chisel, it has a center barbed post in the middle. Kind of an hybrid between a socket and tang chisel. That's why you never see them without their handles :-) And these latest incarnation by Irwin has nowhere the steel qualities of the old Marples Record of the 80s-90s (real Sheffield steel) they are now made in China with a wholly different steel alloy of some sort. Whenever you find the old Marples, buy them, but stay away from these newer Irwin. Your Ulmia may have had its tip soften by overheating while sharpening (power grinding) If so grinding past the edge a bit should give you back properly annealed and hardened steel. Ulmia should be a good one, unless today they outsource offshore like too many others ???

    Bob, chiseling away at these chisels

    1. Hi Bob, thanks for the comments. I can't wait to try this one out. When you say the latest Irwin can't match the steel of the 80s-90s Marples Record, you mean the 1880s-1890s, right?

  6. Nope Matt, i really meant the 1980s-90s still made in Sheffield with good steel. Record and Marles have long separated but both names were bought together and re-united by current owner US Irwin . Yes same company that made the famous Irwin brace bits. They shifted production from Sheffield UK to Mexico and now to China. Really, really not as good steel as the older real UK ones.

    Bob, with Rudy licking my forehead