Making wooden planes: adjustable mouths, securing irons...

[Mike Holbrook]

I am building 4 plane kits, some of the last made by Steve Knight. Since Steve is not making planes any more I was hoping to get a little help here instead of bugging him.

Adjustable Mouths
All my planes are designed to have adjustable mouths. Steve's instructions show wooden mouths with rabbits that apparently were designed to fit in routed grooves in the two halves of the plane body. The bodies I have do not have grooves routed in them for the mouths, just recesses in the plane bottoms. The mouths I have are all in one stick of wood that I will need to saw into pieces to extract individual mouths. The slots for the attaching bolts or screws are routed in the stick. My question is whether or not I should attempt to saw the mouths apart such that there will be enough wood on the sides to make rabbits or not? I would, of course also need to make grooves in the two halves of the plane bodies too. It looks to me like the plane bodies I have are designed for the mouths to simply be fitted to the recess in the plane body, leaving only the bolt or screw to hold the mouth in place.

Securing Plane Irons
It appears that my plane kits have grooves routed in them designed to hold wedges in place against the surface of the 1/4 inch thick blades that came with the kits. It appears that the groves are designed to eliminate the need for any sort of metal or wood rod through the side of the plane body, often used to help secure the plane blades. I suppose I could add some sort of rod through the sides for securing my blades. I am unclear on the relative ability of the grooves in the plane bodies to secure the blades. Steve did send me lots of wedge blanks.

Chip Breaker?
Many planes, even wooden planes, use chip breakers. The kits I have appear to be designed not to need chip breakers. Can I assume that the extra thick irons and wooden wedges will prevent tear out without chip breakers?

Plane Width
The two halves of each plane came routed into a single board. After sawing the two halves from the board each half has 3/8" of the original board still attached to each side. Steve saws this "excess" wood off the sides of his plane in his example but; he mentions that the wood could be left as part of the side of the plane. I was thinking about leaving some or all of this excess wood, at least in the area adjacent to the grooves for the wedges. With the excess wood removed the grooves holding the wedges would be 1/4" + from the edge of the plane. I think extra wood in this area might provide a little additional insurance against the sides of the planes cracking from hammering on the wedges to secure the blades.

Thanks for any thoughts from cave dwellers,

[David Keller NC]

Mike - Pictures would help, but I owned one of Steve's early smoothers in ebony (really wich I hand't had to sell that plane!), and the design is similar to what you describe.

As to the rabbets, I can't help here; my plane did not have an adjustable mouth, and I can't quite figure out what you're describing.

As to securing the blade - yes, Steve's planes are "conventional" in this sense in that the blade is secured in the plane body via a wedge that is secured by two wedge abutments sawn/chiseled into the sides of the plane. That will be more than enough to secure the blade, and avoids the principal objection I have to Krenov's design - a dowel or brass rod that can interfere with shaving ejection through the mouth.

Yes, extra width does help prevent splitting the sides of the plane - many old traditional British-style wooden smoothers have cracked cheeks. But, these cracks are often the result of abuse, not use. A wedge should never be "hammered" into the plane body, it should just be tapped. By driving the wedge hard into the plane body, you risk cracking the cheeks as well as rendering the blade & wedge firmly stuck, and they can be difficult to loosen, particularly with an untapered iron.

You don't need a chipbreaker. The reason for chipbreakers really isn't what is sometimes described in books and old advertisements - that is, breaking the shaving just after the cutting edge to lessen tear-out. The actual reason is that using a chipbreaker allows for using a much thinner blade in a wooden plane (which is cheaper), and in a Bailey-style or Norris-Style plane, it's the part that allows the adjustment mechanism to function correctly.

[george wilson]

But,David,re:The chip breaker; Wouldn't a maker more than waste the savings on a thinner blade by having to make a chip breaker,with its attachment screw,usually a brass,threaded plug for the screw to thread into,and also having to slot the iron? The non-chip breaker irons I have seen are no thicker than those with chip breakers. In fact,in the 18th.C. planes we made,the non chip breaker irons were really too thin to suit me. They had to be very carefully mated to their plane's inclines to keep them from chattering.

[Mike Holbrook]

Thanks for the input David. I should have said tapped not hammered, still the reasoning behind leaving a little more wood in the wedge area is sound.

I can see how a dowel or brass rod might collect shavings and cause more problems than it might solve. The ones I have seen on Japanese Kana are much smaller and I assume less of an obstruction than those I see on some of the recent Krenov designs. It also seems the more expensive Kana often do not have them.

I could see how manufacturers might save money on larger numbers of thinner blades and at least gain a perceived additional feature for their planes by adding chip breakers to their designs. Glad to hear someone voice the opinion that any advantages are overshadowed by a thicker plane iron.

I have a basic drawing of my jointer plane body design, done by Steve. I will try to attach a link to it.

http://www.flickr.com/photos/16891057@N05/6062441322/

[Tony Shea]

Yes pics would really help. I also am unclear about your adjustable mouth description.

And you are correct about the method of wedging the iron in place, no rod is neccessary. The biggest thing you need to watch for when gluing up your peices is that the bed lines up perfectly with the cheek abutments to keep the bed all in the same plane. I actually have never seen Steve's kits so am not sure if this is an actual issue. But I think your cheeks are seperate from the main body, correct? And these cheeks have the abutments already cut in them? So the back side of the abutment in the cheeks is actually part of your bed for the iron. This is the part that needs to be perfect or you'll end up with an uneven bed or have a lot of work to fix the bed. Even if you fixed the bed you would have changed the angle of the abutment which would probably not be identical to the other cheeks' abutment. This part is very important to get right, or you'll be making a lop-sided wedge. Believe me you don't want to have to make an un-even wedge!

I think the original thickness that Steve intended on being there is fine, a 1/4". You could leave a bit more if you're worried but is not neccessary.

[David Keller NC]

But,David,re:The chip breaker; Wouldn't a maker more than waste the savings on a thinner blade by having to make a chip breaker,with its attachment screw,usually a brass,threaded plug for the screw to thread into,and also having to slot the iron? The non-chip breaker irons I have seen are no thicker than those with chip breakers. In fact,in the 18th.C. planes we made,the non chip breaker irons were really too thin to suit me. They had to be very carefully mated to their plane's inclines to keep them from chattering.

George - hard to say what the savings might be. My guess is that before the advent of cheap steel in the late 19th century, it may simply be that the cutting iron alone needed a small (and pricey) bit of steel, and it was cheaper to produce two thinner pieces of iron than one thicker one with a thick piece of steel at the end.

The chipbreaker/blade combinations in wooden planes that I have are considerably thinner than the 18th century single-iron wooden planes that I also own, but it's hard for me to say for sure that there's a definite correlation between a single-iron plane and a thicker blade, mainly because I don't own nearly enough to provide a valid sampling. But I've seen others that have really extensive collections of early planes make the same argument, and my limited collection would seem to bear this out.

While this isn't a bench plane, one 18th century crown molder I have has a nearly 1/8" thick edge at the bevel, which in my view is really massive. This iron, like all the originals I've seen, taper to a very thin 3/32nds" or less at the other end.

Frankly, when I examine these planes I'm really amazed at the different economy of the period. Most of these tools show an incredible amount of human labor that went in the metal and wood work, something that today would be very, very expensive to reproduce. I've gotten quotes before from local blacksmiths for a forge-welded 2-1/2" plane iron made of soft steel with a tool steel edge that ran into the hundreds of dollars. The same blade except made entirely of tool steel was less than half when made by the same person.

[Tony Shea]

You posted before i got my post up. So your setup is just two halves? I suppose you still need to be very careful in lining up your glue-up.

Japanese planes metal rod has nothing to do with holding the blade in place. It is there only when a chipbreaker is being used and is just intended to hold the chipbreaker in the proper location. The blade is wedged and therefore mates up with the wedge shaped abutments. Adding a rod to your plane to help hold the blade is counter productive and would cause either the rod to hold the blade or the abutments/wedge to hold the iron. To get them so both apply the same forces at the same point would be impossible.

[Terry Beadle]

I have a Steve Knight smoother in Bloodwood. Excellent plane. The adjustable mouth is a piece of Ipe and is held in position by two screws that torque into the body. There are no groves that the mouth adjuster piece slides into in this Bloodwood smoother. However, I've also made another smaller smoother in Steve Knight's design ( with a few tweaks ) that use this same adjustable mouth but with the adjuster having a grove ( dado ) in the sides. It too works well. The Bloodwood smoother is on the left. The home made smoother is on the right. The Steve Knight razee jack plane is in the back and it has yet another design for an adjustable mouth. There is an ipe sliding piece in the sole and you use a allen screw to hold it in position.

Enjoy the savings and Good Luck !

205608

[Andrae Covington]

Some pics that may help

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[Mike Holbrook]

Beautiful planes Terry, hope mine come out looking that good!

I hope other posters can see, from the link to the drawing above, what the two halves I will be gluing look like? The two body halves were routed into a two+ inch single Purple Heart board. Apparently Steve has a CNC router and "mad" skills. The gray area in the center of the plane body is a scale representation of the area designed to house the plane blade and IPE mouth block (at least I think the piece of wood containing 11 mouths is IPE, dark brown, heavy, hard wood). The black line inside the gray area represents the groove my wedge would fit into. The long grey rectangle represents a recess for holding one of the totes that came with my kits.

The finished plane would be 1 3/4" tall x 3" wide (unless I leave some of the "scrap" wood) rectangle 26" long. This is obviously not a razee body style but more of a simple rectangular more "Japanesque" design, unless I modify the body. Don't quote me on the "Japanesque" terminology, Stu will hire someone to hurt me. I know the design is far from being a Japanese plane but they seem to be a move in that direction and away from many of the bulkier traditional English/American plane designs.

The mouth blocks in my piece of IPE have 1+ inch grooves routed about 1/2" deep in a 3/4" piece of wood. In the center of each groove a 1" long hole is routed all the way through the board. The two grooves create a ledge for a bolt/screw head to hold the mouth in place. The mouth block would be free to travel the length of the 1" through groove, adjusting the width of the planes mouth. My Idea is to cut the mouths slightly proud and ease the sides down to fit snuggly in the finished mouth area with only one bolt to hold it in place. I am placing an order with Lee Valley for: 1/4-20 wood tapping/threading device, 1/4-20 1" long brass round head bolts, 1/4-20 insert nuts (screw into the tapped holes to hold the bolts with metal threads), 1/4-20 insert nut driver, #10 washers (1" long, shaped to fit the grooves in the mouths).

I have cut the halves of my planes out of the boards they came in, using my band saw. I have been waiting to glue the sides together until I was sure how I would be securing the mouth blocks in the space designed for them. The pieces of the bodies do not appear to have changed shape in any significant way. They have been in my basement shop for over a month. Steve suggests letting the wood adjust to its new environment before sawing the pieces apart and glueing them up. I think all I need to do is lightly sand the surfaces. I just bought fresh Titebond III and extra short clamps from Highland Hardware/Woodworking. My chisels are sharpened and I have some plane floats I found at Highland Hardware too.

The only subject remaining is how to shape wedges from the blanks Steve sent with the kits. Steve's examples illustrate the removal of the wood in the center of the wedges, but I have seen quite a few left as a solid wedge reduced to fit their grooves. Then all I guess I have to figure out is some sort of finish to use on the Purple Heart.

Yes Andrae that looks exactly like mine except mine is not a razee body and my totes are Purple Heart. Same plane irons, I have his remaining stock of 12. I have a few flattened and sharpened waiting to go into use. Why the two holes for the screw through the mouth block?

[Tony Shea]

Hey Andrae, is that blade hollowed on the back similar to a japanese blade? Looks like a real nice set-up, probably should have hit Steve up before he shut down for some kits. Would love to get a hold of one of those planes. I'm more and more getting away from metal bodied planes and using my woodies. Kinda like the feel of wood on wood a bit better. But I will never give up my LN #7, the thing is perfection.

[Mike Holbrook]

Tony I think Steve told me the slightly concave shape on the back of the plane blades is simply a result of the 01 manufacturing/heat treating process. I actually bought the wood to make my planes from one of his local suppliers, he had no Purple Heart left and offered me a close out deal for buying the four kits: two smoothers, a jack and a jointer.

Nice job on your kit Andrae, The wood my mouths are in looks just like yours. I am assuming the stick of IPE? was his remaining stock of mouths. What type of finish did you use on the wood? It looks nice. Did you round over the bottom front corner of your mouth block to help it slide in place?

[george wilson]

Certainly tool steel and wrought iron were both much more expensive in the 18th.C.,since the metals were hand refined. They did start making double irons in the later 18th.C..In Philadelphia,even,if I recall correctly.

[Mike Holbrook]

The parts for Steve's plane kits:
http://www.flickr.com/photos/16891057@N05/6062853737/in/photostream

Tony, Blum Tool Co. will make you something like:
http://www.flickr.com/photos/16891057@N05/6063403564/in/photostream

[Andrae Covington]

...Nice job on your kit Andrae, The wood my mouths are in looks just like yours. I am assuming the stick of IPE? was his remaining stock of mouths. What type of finish did you use on the wood? It looks nice...

...Looks like a real nice set-up, probably should have hit Steve up before he shut down for some kits... Actually Steve built that plane for me, two or three years ago. So he gets all the credit. The padauk body was my choice out of his usual options, he seemed to prefer purpleheart. I'm just not that crazy about purple, but in retrospect the extra weight would probably have been better, especially for a thick-shaving plane like a jack. At the time, we had a conversation about how he was planning to just go to selling kits, which he was already doing. I think his CNC business keeps him pretty busy and there weren't many plane orders any more.


Hey Andrae, is that blade hollowed on the back similar to a japanese blade?...

Tony I think Steve told me the slightly concave shape on the back of the plane blades is simply a result of the 01 manufacturing/heat treating process...
I believe that's correct.


...Why the two holes for the screw through the mouth block?... Not sure about that, maybe he changed his mind.:D:confused:


...Did you round over the bottom front corner of your mouth block to help it slide in place? ...

My guess is he did that to make sure there was clearance when the sliding mouth is pushed all the way forward, to not hang up on the front inside corner of the mortise, which might cause the sliding ipe part to drop down below the sole of the plane.

[Mike Holbrook]

Thanks Andrae,
Especially helpful to see how Steve made the mouth for your plane. I feel comfortable doing exactly what I was planning on. With a final plan in place I can glue up my plane halves.

I will have a little file/chisel/ sand paper work to do in the plane iron bed. I believe Steve routes that area slightly concave so a little filling on the two open sides levels things easily. I am thinking about a Krenov style dip in the front of the plane body to stabilize the grip there, either that or a knob. I think something in the plane body would be preferable to a knob though. I think I will play around with how to grip each size plain before I finalize the body shapes as I suspect the length and weight of each plane may alter preferable gripping methods.

Steve mentioned a ways back that he was talking with someone who might have interest in continuing to build either his planes or the kits. I for one hope Steve is not gone from the world of wood planes permanently. It is very nice to have the important areas of a plane routed by a CNC router and someone who knows how to use it for this work. Although I imagine I will have to do an entire plane by hand at some point, the thought of hand cutting the area for the plane blade and wedge is daunting at the moment.

[george wilson]

The 18th.C. style single iron planes we made for all the craftsmen in the Historic Area in Wmsbg. had VERY thin irons,made by the blacksmiths. They were TOO thin,in my opinion,but they insisted in making them very thin. The planes had to be carefully bedded against their irons by hand with floats to prevent them from chattering. Those blades were no thicker than double iron plane blades.

The curator had the ridiculous notion that ALL planes chattered in the 18th.C.. It did no good for me to protest against these thin irons,which were based on used up old irons from the 18th.C.,in my opinion.

[David Weaver]

Just want to stick my nose in for a second and mention that on price lists where a planemaker offered double irons and single irons, the single iron planes were (on all of the lists I've seen) cheaper. The cutting steel might've been slightly larger on the single iron than the double iron plane, but most of the iron was wrought iron, anyway.

I'm sure if we get into the discussion of whether or not a double iron was better, it'll go the same way it always does. On old planes, i don't think it was because all but the smoother had too much radius for it to do much (at least on my planes), but a lot of people seemed to have thought it was, and craftsmen were paying more for the double iron planes by a fairly significant amount (I can't recall exact numbers off the top of my head, but it might've been something like 1.40 for a single iron bench plane and 1.70 or 1.80 for a double iron bench plane of the same type.

My best working wooden plane is a single iron jointer from the early 1800s. It has stayed tight with very little attention to the wedge, and the mouth is cut nicely so that it's not loose and not tight.

The other thing I've not noticed, and maybe this is because of the age of the planes and the age-related illnesses the chipbreakers have received - is any double iron plane where the second iron was clean enough (they are rough and not sharpened) at the edge to be close enough to the edge to do anything other than stabilize the iron (i.e., they're not close enough to break chips).

Maybe having a thinner iron was preferable to sharpen. I know several people who like the thickness and hardness of the original stanley irons because they allow faster freehand sharpening.

Does anyone know of a definitive writing about double irons, and not just one based on one or two ads, or a bunch of opinion? I have seen ads and instructionals where the setup of the edge was prescribed "to properly eject chips", and breaking them or improving a surface was never mentioned. I have no doubt that a second iron can improve the performance of a plane if it's set up close enough to the edge (like 3 thousandths from it on a smoothing plane) but I've never seen an old plane that was set up to take advantage of that.

[Mike Holbrook]

David,
I think you make some good points David. It is the old features vs benefits question. The features of any product may or may not provide a real benefit to a specific user of that product. Features, however, often sell products regardless of whether or not they will provide a benefit to the specific buyer. One can certainly argue whether or not any benefit derived from a particular feature is cancelled by issues that the same feature causes. A major issue with any perceived benefit of a feature is whether or not the benefit is worth any effort required to achieve that benefit.

Here in the cave, there are a good many people who are trying to eliminate extraneous features in favor of simpler hands on methods. Certainly many people find
chipbreakers to be useful. Certainly there is some amount of "care & feeding" necessary to keep this additional part providing whatever benefits it might provide. Personally I am good with eliminating the part if I can produce the same results without it. A friend of mine makes a heated argument that there is a time and accuracy cost associated with eliminating chipbreakers. From what I have read and experienced I find that cost to relate more to the individual's experience and mind set than particular time or labor savings associated with either the single or double blade methods. The main issue I find with the single blade system is a comparative lack of purchasable quality parts. Since I just happen to have a sizable stock of good 1/4" thick 01 blades designed for my planes; I have no issue. Although I am keeping my eyes open for other options.

Plane Hammer?
I believe an appropriately designed plane hammer will be a significant aide and reduce damage to my plane body & blades. I see lots of designs and kits for making these hammers. The LV offering looks quite attractive. The hammer has a brass head with a wood insert on one side. Since I see both wood & brass hammers used for this work having both sounds attractive. I am a little concerned about weight though. I have read suggestions that such hammers need to be 4-5 ounces. This particular hammer has an 8 ounce head. I am interested in what others use to tap-tap single blade planes and how/where the tapping is done.

[Mike Holbrook]

So my first plane takes shape:

http://www.flickr.com/photos/16891057@N05/6079149811/in/photostream/
15 1/2" x 3 3/8" at the moment...Jack Plane

I was planing down the board that still existed as a ledge on both sides of the body. I ripped the width narrower on the table saw (see the remainder of the board as a gray area on either outside edge). Yes, I left a little extra to play with and provide a little extra insurance around the blade & wedge.