First time Vintage Buy - "Pig Sticker" Mortice Chisel

[Assaf Oppenheimer]

Hi everyone,

After listening to some advise from some wise creekmembers I put out feelers for a "pig sticker" mortice chisel. the one I found was 5/16" or the next best thing in mm. length of blade is 6 10/16" with no pitting. It does have a crack in the handle which extends to the other side. The maker appears to be Sorby - there is no reference to Sheffield on it.
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Questions
- Does anyone have any information on dating these chisels?
-Should I be concerned about the handle? I bought this for mortising a workbench I plan on building
-I am new to woodworking, I know these are considered easier to sharpen by hand, but at the moment I would rather use a guide. does anyone know if they work with the LN guide?


thanks

[Mike Henderson]

That chisel is in good condition - I wouldn't worry about the crack in the handle. I don't know Sorby chisels very well, but that one looks fairly recent (in antique terms).

I think the best way to sharpen them is to shape the primary bevel, perhaps on a slow speed grinder, or on a diamond plate, and then put a secondary bevel on it. Trying to shape the whole bevel on stones will take a long time. The bevel looks like it's a good shape already so maybe all you need to do is work on the secondary bevel.

I suppose you could put the chisel into a guide but I never tried that - I always worked my pigstickers freehand. Don't be afraid to try sharpening it that way.

Mike

[Stephen Rosenthal]

Lee Valley has a mortise chisel attachment for their Mk.II narrow blade guide, which is an alternate head for their Mk.II honing guide. Lie Nielsen has dedicated accessory jaws to sharpen their mortise chisels, but I don’t believe they accommodate any other brands.

[Rob Lee]

If regrinding, make sure to leave the rounded part at the top of the bevel - used as a fulcrum for levering out waste. That shape is deliberate!

Cheers -

Rob

[David Bassett]

... -I am new to woodworking, I know these are considered easier to sharpen by hand, but at the moment I would rather use a guide. ...

Someone recently posted a link to Matthew Platt from Workshop Heaven Sharpening and Using Mortice Chisels that seemed a pretty simple explanation to me. (Sharpening part seemed pretty universal, whatever guide or not the goal is the same. For mortising there are many other techniques, e.g. drill a relief hole before chopping or drill out the whole mortise before squaring and smoothing with a chisel, but his seemed pretty standard chop-only method.)

... does anyone know if they work with the LN guide? ...

No. Sorry.

[Andrew Seemann]

The crack in the handle probably not a problem. Not sure on the age, other than it is old enough be a good chisel. I would only use a non-metallic hammer/mallet with it though.

Sorby is typically well regarded as a brand. The chisel looks like it is good condition and just needs the tip sharpened. Also note that the profile looking down the chisel is intentionally not rectangular, it should be wider along the cutting edge side and tapered in, so the sides of the chisel do not drag in the mortice while levering out material.

If you do a power grind, make sure you don't overheat the steel, thus weakening it. I had a tip snap off of one of mine.

[Warren Mickley]

Thanks for the Platt video, David. As you can see, he rides the bevel of the tool. I have used this method since 1978. Note that this method causes the tool to move horizontally with each cut, which is sort of self jigging and helps keep the cut vertical (side to side) and helps true the sides. Riding the bevel as we do, we don't want a secondary bevel, which would impair the stability of the cut. Also notice he does not have a rounded portion of the bevel. There is no need for the top part of the bevel to be rounded.

A lot of the other videos I have seen looked like the guy just practiced making mortises for the video, then went back to his machine methods. It is nice to see a video in English where the guy seems competent.

[Mark Rainey]

Yes, David and Warren. Good video. Interesting that he polishes the sides of the chisel after the back, resulting in a 90 degree but still sharp edge that he states helps cut the fibers along the lateral walls. I always wondered how wacking a mortise chisel cut the side walls in addition to the depth. I have cut hundreds of mortises by hand and have not polished the edges. Perhaps this will improve my mortises. I will give it a try. Although one would have to be careful to keep the angle square to the back for both edges. Which leads to an old discussion between Ian Kirby and Frank Klauz. Ian liked mortise chisels square whereas Frank liked the chisel tapered on the sides from front to back so he could maneuver the chisel in case he went a bit off track.

[Scott Winners]

LN does have a set of "mortise chisel jaws" that fit their honing guide. I have a set of the mortise chisel jaws and my LN mortise chisel fits it just fine. If the cross-section of your mortise chisel is square or rectangular the LN mortise jaws will probalby hold it just fine.

For mortising I remove everything I can with a drill before I reach for a chisel...

[William Fretwell]

That chisel does look rather narrow for the mortices you plan on making. That style of chisel with the square ‘sharp’ edge can cut a mortice the same size as the chisel.

[Warren Mickley]

A little over forty years ago, Ian Kirby wrote a series of mortise and tenon articles for Fine Woodworking. He mentioned having the chisels square. Frank Klausz wrote a very indignant letter to the editor claiming that a mortise chisel needed to be tapered back to front so you could steer it. Kirby did not respond.

Here is the thing: If any part of the chisel is wider than the cutting edge or maybe wider than the back of the chisel, there can be problems of the chisel binding in the cut. Because we can't make a perfect chisel, perhaps a little taper is helpful to insure that something is not wider. However, the thickness of the chisel is what helps insure that the chisel self jigs and registers with the hole already cut to make a precise mortise. We do not "steer" the chisel. A very small taper in width and in length can be helpful, but it should be in relation to how precisely the chisel is otherwise ground. A precisely ground chisel needs very little taper.

I remember at that time Kirby also wrote about a method of cutting tenon shoulders. He made a knife line where the shoulder was to be, sawed 1/32 or less from the line, and cut with a chisel in the knife line. I used this method for about a year. Klausz thought this was terrible. He said this method requires a "master cabinetmaker with a very sharp chisel, and I beg the beginner to avoid it." I did not think I was a master cabinetmaker, so it kind of made me feel good that I could toss this off.

About the polished edges. It is difficult to abrade the edges without getting slightly convex, which again causes binding problems. This needs to be done very carefully. Also you don't want the chisel narrower at the bevel than tow or three inches back. It is safer to sharpen the side edges by working the back.

[Assaf Oppenheimer]

That chisel does look rather narrow for the mortices you plan on making. That style of chisel with the square ‘sharp’ edge can cut a mortice the same size as the chisel.

It is 5/16" I plan on restoring it and getting a feel for them. for the bench build I will probably buy a Ray Illes 1/2" pigsticker - provided I get some enjoyment out of this one.

[Warren Mickley]

It is 5/16" I plan on restoring it and getting a feel for them. for the bench build I will probably buy a Ray Illes 1/2" pigsticker - provided I get some enjoyment out of this one.

5/16 is a handy size for table legs or for frame and panel work. For larger mortises you could make a 5/16 mortise on each side of a one inch mortise for example and then jut chisel out the center.

[Jim Koepke]

5/16 is a handy size for table legs or for frame and panel work. For larger mortises you could make a 5/16 mortise on each side of a one inch mortise for example and then jut chisel out the center.

Or one could learn to cut a double tenon.

Depending on your preference a 5/16" chisel works for a third of a 1" piece after truing and smoothing would likely measure in at ~15/16".

Some advocate a tenon should be half the width of the rail. This would work with a 5/8" piece of stock.

Also most of the 1X fir in the big box is 3/4" stock. A 5/16" mortise would likely work fine.

jtk

[Tom Bender]

Warren you have a remarkable memory for 40 years ago, but do you remember what you had for lunch yesterday?