It’s the Bulge

Several people have emailed me pointing me to different places where I’m told I can buy the style of striking knife I just finished making.  To all of those people, I offer my sincere thanks. But the fact is that none of the commercially available knives are quite right. They all lack “the bulge”.

It’s not really evident in the knife I just made, because I simply got tired of filing metal away.  So the bulge on my knife is not very pronounced.  But it’s there, albeit not as deep or as shapely as I would like it to be. For reference again, here is the Smith’s Key knife.

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Note how behind the knife blade, the shaft tapers in, then bulges out, then tapers down to the awl point.  Here’s a photo of Christopher Schwarz’s antique version.  Note the same bulge.

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This bulge lifts the awl end off the bench, making the knife easier to pick up, and it makes it settle into the hand much nicer than a straight taper.  All of the other knives that I’ve found available commercially that are a similar style do not have the bulge.  They have a straight taper from the knife to the awl.

Here’s one I bought from the smiths at Williamsburg next to the one I just made. The Williamsburg knife has no bulge. In this overhead shot of my new one, you can see the slight bulge a little better.  It’s more noticable in the hand than it is by eye. Like I said, I would like it more pronounced (and I may someday grind it down some more), but I can feel the difference.

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And the standard knives currently sold by John at Black Bear Forge. Again, straight taper (though I’m sure John can forge in a bulge, his standard knives just don’t have one).

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And finally one from Woodcraft. Sorry, but this one is just plain ugly, and that knurling looks down right uncomfortable for long sessions marking out lots of joinery.

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So thanks again for all the suggestions, but I’m still looking for a good commercially made example like the one in Smith’s Key with a nice round handle with “the bulge”. Though now that I’ve made one, I guess I can stop looking.

Smith’s Key Striking Knife

So I just finished a new striking knife based upon the one pictured in Smith’s Key.  I’ve made a lot of striking knives in the past, and used a bunch of different commercially available models as well. However, none have felt as nice to me in use as this one. Maybe it’s just because this one has been more work to make than any other knife I’ve ever made or used. But I don’t think so. Something about that swell just behind the tapered blade that just makes it fit the hand so well.

This is probably an easy tool for a blacksmith to forge, but for someone working from 1/4″ thick O1 stock and using nothing more than a hacksaw and file (and maybe a little help from a belt sander and grinder), it’s just plain tedious work.  Not the kind I enjoy either. But it was worth it. I love the look and feel of this knife. However, I won’t be making any more.

Someone out there needs to start making these again, though. Please!

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A Special Pair of Saws

A couple of months ago, I saw the very saddening news that Stephen Shepherd, proprietor of the Full Chisel Blog, had suffered a serious stroke. I have been a follower of Stephen’s site since its very early days and had communicated with Stephen somewhat regularly through email and our two blogs over the years. While we have never had the chance to meet in person, being physically separated by almost an entire continent, I have always considered Stephen a friend. So it was very hard for me to hear of this event. I was and continue to be very thankful that Stephen survived the ordeal and that his condition continues to slowly improve with therapy. But it is still hard to think that he may never put a tool to wood again. 

Recently, I was browsing the big auction site as I occasionally do, and I stumbled across two auctions for saws that looked very familiar to me. The seller advertised them as “Shepherd” gentleman’s saws. When I inquired with the seller if they were a friend of Stephen’s, they simply replied that they did not know Stephen. I didn’t ask where the seller obtained the saws from, but I did press the Buy It Now button on both to ensure that they continued to stay together and that they continued to do the work that they were so carefully crafted by Stephen’s hands to do.

I do hope that you continue to recover Stephen, and that by God’s blessing you are one day able to put tool to wood again. In the mean time, I hope that you can at least find some satisfaction in knowing that these saws will become a permanent addition to my tool kit, and that they will continue to live on and work as they were intended to do for at least the rest on my days. Godspeed my friend.







Plane & Spokeshave Details

OK, so a little more detail on the plans for the planes and spokeshave are needed.  As noted in the comments in the previous post, the layout on these tools has not been done yet.  They have been planed to dimensions necessary prior to layout, but no layout has been done.  I’ll go over that.

For the spokeshave, I’m using a pretty piece of hard maple, but just about any relatively dense hardwood would work.  There’s going to be a brass wear plate attached at the front of the sole, so the wear characteristics of the wood are not that important. It will be helpful if your particular piece of wood is dense enough to be tapped for machine screw threads though. This isn’t critical, but it allows you to add a nice little feature for adjustment if your wood can hold the threads.

I ripped the blank out of a 5/4 flatsawn board, so the wide top and bottom surfaces are quartersawn faces.  This is mostly for the appearance and because it’s the stock I had.  Turning the grain orientation the other way so the flat sawn faces are on top and bottom would be fine too (i.e. just sawing a blank out of a 3/4″ thick flat sawn board).  This is a small tool with a small cross section.  The amount of wood movement is going to be so small that we can more or less ignore it in such a small piece.

Spokeshave

Here’s a pdf of the above picture.  If you print it out on legal sized paper it will be full scale and you can use the drawing as a template for sawing and shaping later.

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Download Full Scale Spokeshave Plans

In terms of the blade, there are multiple options, but the blade you choose will impact the blade mounting steps, the mode of adjustment, and possibly the dimensions of your blank.  So I suggest getting a blade ahead of time, before you cut your blank to size.  Then you can compare the dimensions of your blade to the dimensions of mine in the drawing.  I made my own blade, so it is highly unlikely that the dimensions of your blade will match mine exactly (plus I didn’t measure my blade super accurately with a caliper or anything like that).  You will have to make some minor adjustments to the pattern to fit your own blade.

Of course if you’re up for it, you could also make your own blade like I did.  Then your blade could be made to match the dimensions of mine, or any dimensions you desire.  I’m not going to go over that process though.  It’s pretty straight forward (obtain 1/8″ thick O1 tool steel; cut out the shape of a spokeshave blade with a hacksaw & files;  drill & tap holes for threaded rods; grind & harden blade).

Hock Tools sells a blade that is similar in dimensions to my homemade blade (their larger blade), but it’s not exactly the same, so you’ll need to modify the plans to fit the blade.  However, if you buy the Hock blade you will be able to follow the exact same construction process as I will be using as the blade adjustment will work the same way.

Another blade option is the Lee Valley kit. The adjustment mechanism is different on this kit though, so you will likely have to alter the dimensions of your stock from what I’m using in order to use this kit. They should have instructions and recommended stock size available on their web site.

OK. We’ll do the plane blanks next time.  I’m going to build the spokeshave first.

Wooden Plane Throat Geometry

I love old wooden hand planes. There’s something about tuning up a 150 year old woodie and putting it back into working order that is very satisfying to me. The thick laminated irons, the feel of wood on wood, and the simplicity of having no moving parts has a special appeal that I just don’t get when I use my iron planes.  I’m not saying that I dislike using my iron planes. I just like using the woodies more.

From the rear, a 2 ¼" x 8" x 47 ½ degree double iron smooth plane, a 2" x 7 ¾" x 45 degree double iron smooth plane, and a 6 ½" x 1 ¾" x 55 degree single iron smooth plane.
From the rear, a 2 ¼” x 8″ x 47 ½ degree double iron smooth plane, a 2″ x 7 ¾” x 45 degree double iron smooth plane, and a 6 ½” x 1 ¾” x 55 degree single iron smooth plane.

But have you ever wondered why most old wooden planes found in the wild have mouths that you could drive a Stanley #8 through? This condition is typically attributed to wearing down of the sole from use and routine re-flattening. And while it’s true that routine maintenance of a wooden plane will open up the mouth, there’s a little more to the story than just routine maintenance and wear.

Throat geometries of single iron and double iron wooden planes.
Throat geometries of single iron and double iron wooden planes.

The lower front of the throat on a wooden plane is called the wear. This area of the throat angles over the iron for about an inch before angling back in the opposite direction to form the upper throat where the shavings can be removed. The closer the angle of the wear is to the bed angle, the less the mouth will open as material is removed from the sole during flattening. In an ideal situation the wear angle and bed angle would be the same, but the wedge adds about 10 degrees so obviously that’s not possible. But there’s more to consider.

Observe the two drawings above, representing the throat geometry of a single iron and double iron plane. Notice how it’s fairly straight forward to create a nice tight mouth on the single iron plane. The wear in a single iron plane typically angles back over the bed at an angle of about 15 degrees greater than the bed angle. This provides for about 10 degrees for the wedge and another 5 degrees to provide for a bit more clearance for the shaving to be ejected. So in the drawing on the left above, the iron (red outline) is bedded at 50 degrees and the wear is cut at about 65 degrees.  In this drawing, notice how the front of the mouth is easily made right up against the cutting edge of the iron.

Now look at the drawing of the double iron plane to the right. Notice how the presence of the chipbreaker impacts the angle of the wear.  In this drawing, in order to create the same tight mouth that the single iron plane has, it was necessary to increase the wear angle to almost vertical. With a wear angle any less than the illustrated 80 degrees (a full 30 degrees more than the bed angle), the chip breaker would prevent the iron from being able to be extended through the mouth because it would contact the wear.

This is kind of interesting, because when we look at most double iron wooden planes, the wear angle is typically around 70-75 degrees. But based upon the drawing above, we’ve already established that if the wear angle is any less than 80 degrees, then the chip breaker would contact the wear and wouldn’t allow the iron to extend through the mouth (and if, by chance, it did, the shaving would get trapped between the wear and chip breaker). That is, unless the mouth was opened slightly.

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By opening the mouth up slightly, the wear angle can be kept lower.

As shown in the drawing above, 19th century makers of planes with double irons made a compromise. Most didn’t want to use such a steep angle on the wear because routine maintenance would result in a mouth that opened up very rapidly. So to slow the opening of the mouth, they chose to keep a slightly lower (70-75 degree) wear angle, albeit not quite as low as those found on single iron planes. However, in order to let the double iron through, and permit the shavings to pass over the chipbreaker, they chose to make planes with mouths that weren’t quite as tight as those on a single iron plane. Seems kind of like robbing Peter to pay Paul, doesn’t it? You open the mouth a bit right from the beginning in order to keep it from opening as fast later on.

Some would criticize double iron planes because of this.  However, proper use of the double iron more or less eliminated the need for the tight mouth that was so necessary in single iron planes. With the edge of the chipbreaker set very close to the edge of the cutting iron, the chip was broken before it had a chance to tear out, so the mouth could be slightly wider without any loss in performance. Unfortunately, this allowed wooden planes to be manufactured by less skilled workers as the 19th century progressed (many American wooden planes were made by prison labor later in the 19th century).  This eventually led to the demise of the wooden plane as the quality of these tools declined to the point that they were completely replaced by the modern iron hand planes.

The typical mouth opening of a "new" double iron wooden plane.
The typical mouth opening of a “new” double iron wooden plane. This plane has the tightest mouth of all of my wooden bench planes.

The plane pictured above is my 8″ long smooth plane with 2 ¼” wide double iron bedded at 47 ½ degrees. This plane was virtually unused when I bought it several years ago, and has seen very little maintenance flattening since then. As you can see, even though very little of the wood on the sole has been removed since the plane was made, the mouth is still much wider than what most would consider acceptable for a smooth plane today. However, with the chipbreaker set properly, I haven’t had any problems smoothing any of the woods that I typically use. In fact, I’ve never had a problem with any of my other wooden bench planes either and they all have even wider mouths than the smooth plane pictured above.

To me, this suggests that mouth opening on a double iron plane is less important than most people make it out to be, for the majority of situations. Sure, for some of the really squirrely grained boards that we occasionally run into, a really tight mouth might provide some limited benefit. But for the typical work that most of us do, I just don’t think that mouth opening on a double iron plane is all that important. A sharp blade and a close set chipbreaker are much more important in a double iron plane than a tight mouth.

In the coming weeks I will be making two new smooth planes using some old irons I have.  One will be a double iron plane, using the 2″ wide double iron from the middle plane pictured above (I bought the plane just for the iron). The other will be a single iron plane made using an old 1 ¾” iron given to me by a friend (not the one in the plane pictured above).  I’ll do my best to document the builds here, so that you can get an idea of the process in case you want to give it a try for yourself. Who knows, maybe I’ll even film the process. Stay tuned.