Broken Tip R Iles Mortise Chisel

[Roger Nair]

Given that this is a $70-ish chisel sold by a dealer who stands by their products, I think that any discussion of topics other than contacting the dealer is moot (not "mute", though I'm continually amazed at how many people mess that up).

Yes, oops, on the other hand the point could be mute because it does not speak to effect. The dealer should be out of the picture after a few years after sale and the tool has been accepted.

The tool as provided may have been optimized to woods that are on the soft side of the spectrum. It is up to the craftsman to adaptively sharpen tools to the materials used in a project. My suggestion is all about getting to work and adaptation is an iterative process to find an ideal in use. Whatever input a dealer would have is questionable since the dealer normally is remote from the bench.

[David Eisenhauer]

Thanks for the responses. I will not (never considered) send the chisel back for a refund/replacement. etc. I think, perhaps, that some of you may be making more of this than I am and I am not driving any metallurgy talk or unduly unhappy with the chisel. It happened. If it happens again with the same chisel, now perhaps there really is a problem with this particular chisel. I merely thought it may be of some interest to any who had not seen a broken tipped chisel before and related the events that resulted in the break. I saw a couple of opinions expressed as to my mortising technique, but I believe my technique is fairly consistent with traditional methods with the exception of my mallet work - I do not attempt to achieve maximum chisel penetration on each strike at all. Pat - I don't believe that I am performing "significant levering", with a 1/4" depth achieved per (total of two mallet strikes) chop and a single pull/push on the chisel to loosen (not eject) the chip. I scrape/clear debris with a bench chisel when I complete a run through the length of the mortise. I believe someone wrote of creating a final working edge with a convex profile that sounded interesting, but I do not know how to create a convex profile. I have continued using my former mortising chisel (registered/firmer type Sorby chisel with an assumed O-1 steel) that is more flexible by far than the R Iles, but works well using the same technique as when I use the R Iles. The Sorby has a 25 deg primary bevel and a 35 deg secondary or micro bevel. I tried it out a few years ago on some of this same pecan with a 30 deg secondary bevel, but I encountered excessive edge rolling so I steepened the final cutting angle up and the rolling disappeared. As I originally stated, maybe I broke it, maybe it broke, but, at any rate, I will re shape/sharpen it back to the same profile I originally had on it and re use it to see what it does. I will try to go to Brian's suggestion of a double pass down the length of the mortise and only lever on the second pass. That should prevent any future breakage.

[Nicholas Lawrence]

David, the only thing I can add is that I learned a lot from watching the mortising video Paul Sellers has on Youtube. Your mortise looks pretty even in depth all the way across. When I do them, I do more what Sellers shows in that video, with the mortise increasing in depth as you go along. With the bevel, that results in the chisel “pushing” the waste to the side, into the space left by the prior cut, so there really is not a lot of pressure or stress involved. What is being levered out is already broken loose.

I have seen others (can’t remember where unfortunately) do something similar by drilling a hole at one end of the mortise. The waste is then forced sideways by the bevel into the hole, and again pretty much broken loose before you get to the point of trying to lever any of it out.

I am curious how you managed to get the broken tip out? I broke a drill bit in a project once, and was never able to get the broken tip out.

Don’t know if any of that helps or not, but good luck once you get it ground back the way you want it.

[David Eisenhauer]

Nicholas, the photo of the mortise was taken after I used an upside down 1/4" bench chisel to clear out and level out the bottom surface of the mortise to better expose the broken piece for removal. After cleaning and levelling the mortise bottom, I chopped in front of and behind the piece with another 1/4" chisel and used a bench chisel in the front/back chops to create a little "wiggle" room for the broken piece. I then was able to pull the piece out pretty easily. I have seen the Paul S videos and my technique is pretty much the same (only he is a lot quicker). My mortises also go deeper as I progress along the length of a mortise. This pecan seems to create individual chunks when chopped as I progress along the length and Brian's suggested double chop technique should result in smaller/less dense chunks for clear out.