Making a new nicker for a dado plane - hardness?

[Jessica Pierce-LaRose]

I recently picked up a 1/4" dado plane for cheap - it seems straight and true where it matters. Took the irons and wedges out because they were a bit tight, but haven't played for it. I figure I'll let it get used to the new shop for a few days at the least. (at least, that's what I'm telling myself my laziness with it is)

Oddly enough, the "skate" (for lack of a better term) is worn a little thin in width ahead of the mouth, but on the "inboard" side - that is, things are straight and true on the side you'd run against a fence, and only worn on the opposite side. I'm thinking that means it won't be an issue, but we'll see. I've kind of been snagging a lot of cheap stuff on eBay and this maybe wasn't my best idea, but the price was low enough it's not a total wash - almost worth it for the depth stop hardware.

Anyway, the one thing I missed before bidding is that the nicker is quite worn, to the point where one of the tips is almost gone. I'm going to see if I can't carefully touch it up, but it looks like it already might have been sharpened a bit thin - it's thinner than the iron, which may or may not be an issue, as the iron looks a bit wide for the plane.

I'm pretty comfortable tuning this guy up - I've played a bit with dado planes before - but initially, at least, it's looking like I might need to make a new nicker iron for it. Once I get into it, I'll find out.

The nicker irons I've come across in dado and filletster planes are soft enough you can touch them up with a file. Does this mean they're heat treated to a lesser hardness, or not treated at all? Would I be fine making an iron out of some O1 or something and just using as is, or do I want to harden and temper it still, just to a lesser degree?

I know little about metallurgy, although I have enough reference materials at hand I feel I could probably harden a plane iron, (although I haven't done it yet, so it might take a couple attempts) but I'm not sure what I should be shooting for in a nicker iron, so I'm not sure what I should be looking into here. Any pointers?

[David Dalzell]

I have never really looked closely at nickers on planes; but with just casual observation the nickers look like the cutters on various marking gauges. Would any of those be adaptable to ypour plane?

[george wilson]

Hacksaw a bit of a saw blade off an old saw and file it into a nicker. Don't use a piece of hacksaw blade itself as it will be too soft. Only the teeth on most hack saw blades are hardened. A piece of bandsaw blade will do also. These items will be about the right thickness for a nicker,too.

[Jessica Pierce-LaRose]

David -

Not without serious modification to the plane - this one is of the type pictured in this thread (http://www.sawmillcreek.org/showthread.php?123079-Dado-Plane-Nicker) . I actually just plopped the plane together to see if the nicker would work - it actually seems like it might be okay with a little fettling. I won't know for sure until I get a chance to tune it. I realized the width issues I thought I was forsee-ing between the nicker and cutter might not be an issue, I didn't think about the fact that the cutter is skewed and the nicker isn't.

I'm still not sure if I'll have to re-do the nicker or not at this point - but I'll see. Hopefully I get to this sooner rather than later. I've read the maker (A.M. Seaman's of Ithaca) was from the late 1800's - he certainly picked terrific stock for this plane - the fleck from the quartersawn wood is quite attractive on the side, and it's certainly stayed a lot more stable than a lot of dado planes I've looked at.

[Jessica Pierce-LaRose]

Ah - good idea George. Hadn't occurred to me. I'd probably have to make a new wedge as the nicker iron on this plane is quite thick, and I'd hate to saw off the tip of the wedge (it's in very good shape) but that's probably the quickest route. Thanks a lot!

[george wilson]

Nickers are never needed to be as thick as the plane iron. about 1/32" will do. They need to come out flush with the side of the plane plus a few thou.. However thick they are depends upon how deep the recess they fit into is. Lie Nielson makes their nickers stick out something like .002" wider than the plane iron. If they don't,the plane iron will continue to tear the wood as if there were no nickers at all. If you have no nickers,scribed lines are cut with a knife on either side of a dado to keep the wood from tearing.

[Jessica Pierce-LaRose]

. . . However thick they are depends upon how deep the recess they fit into is. . .

This is the style of knicker like another wedged iron, in a vertical position (actually slightly canted back) rather than in a recess, hence why it was so thick. Like the one's pictured in this thread: http://www.sawmillcreek.org/showthread.php?123079-Dado-Plane-Nicker

That's why it was so much thicker.

[george wilson]

Well,a picture would have been very helpful. I was thinking about a much different style of nicker.

No,you can't just make a nicker out of thin metal for that type. You need to buy a piece of 1/8",3/32",or whatever thickness 01 steel you need. The nicker is probably tapered too. That will have to be ground into the nicker with a belt grinder,or could be filed in a few hours or even less (I take longer than I used to!) 01 is supplied annealed and MUST be hardened. You only have to harden the very end where the cutting spurs are. Use a Mapp gas torch. Put 2 bricks together to make an L shape,and lay the finished nicker in the corner of the L. Have a can of vegetable oil,automatic transmission fluid or CLEAN motor oil( NOT USED!!!). You could even use as pint of linseed oil! Heat the end ORANGE hot. Quench it immediately in the oil. USE AT LEAST A PINT OF OIL. The quench needs to be big enough that it does not get appreciably hotter when the tool is quenched. I use a gallon myself,but intend to buy 5 gallons of automatic transmission fluid for a decent quench tank. Wrap wet or dry paper around a file,and sand the metal bright. ONE side will do. Heat the iron above where the end with the nickers is. Let the colors creep towards the nickers. When the brown color,or even BLUE color gets to the nickers,quench it at once.

Blue is a spring temper,as hard as a GOOD saw blade so you can file the nickers sharp if they get dull. Don't worry about the hardness or softness of the rest of the blade. Only the nickers matter.

[Steve Voigt]

If you have a dremel or an angle grinder, but you don't have heat treating equipment, an alternative approach is to cut up an old plane iron or jointer knife. I use a 4 1/2" angle grinder. If you can set up outside and arrange to have a trickle of water dripping on the blade, it will help. Stay far away from your layout lines and then grind to size on a bench grinder or sander.

[george wilson]

MUCH easier to just get his feet wet and learn elementary hardening and tempering. Most anyone has a propane or Mapp gas torch. I wouldn't even want to try cutting up plane blades with a Dremel tool. Too much breathing metal dust to suit me. But,I have copd,and am a lot more particular about what I breathe than when I was young!

Once you learn how to harden and temper just 01(a simple steel to deal with),a whole World of making your own tools opens up. Next,he can be hammering red hot 1/4" square stock into a flared end,and making his own fish tail gouges and dovetail chisels. ANYONE can learn to make simple tools like these. And,they cost so little to make. Mostly,you are not any longer at the mercy of what you can buy. THAT'S what I like the most. Grinling Gibbons made many of his own tools as the need arose.

[Steve Voigt]

George, I completely agree about the virtues of learning to harden tool steels. I was just suggesting a one-off solution for those who might not own a torch (I don't, currently).
Beautiful tools in the above pic, by the way.

[Steve Voigt]

George, slightly off-topic question. Have you ever tried forge laminating? I am close to finishing a small forge (just need to get a blower), and am intrigued by the idea of trying to make a traditional tapered, laminated blade.
Thanks,
Steve

[george wilson]

No,we left making laminated plane blades to the blacksmith's shop. I know they used something like 1070 or 1080 steel because it was easier to weld. 1095 burns up too easily. I didn't like hat,but that's what they used by necessity.

The straight handles are quick anmd dirty: I had to re handle close to 100 carving tools I bought. Their user made handles were like deformed potatos.

[Noah Wagener]

George,

Were blades laminated as a steel savings measure or for better performance? In your opinion does it effect performance much? I can get my thin Stanley jack blade sharper than the 2 cast steel blades i have and it stays sharp longer too. The Stanley blade is not laminated by thickness but it is split in half lengthwise half tool steel, half something softer.

Should those cast steel blades be performing better than the Stanley if they were properly heat treated? From what i've read here I understand steel marked cast was not always that consistent so there is no way for you to know but I've also read in a couple hand plane books to seek out cast steel. Is there an optimal bevel angle for this type of steel as well? I watched a video where a guy was sharpening using a training jig he sold and it only had 2 angles 29 and 31 for micro bevel. Aren't you supposed to vary angles depending on intended work, type of steel, and vary even more for bevel up planes?

Now i getting off the off-topic topic. Sorry.

[george wilson]

Steel was laminated as a steel savings measure. Steel was hand made,especially the farther back you go. Even in more recent times into the 20th. C.,steel was made as "crucible steel",where it was made in a crucible and poured into ingots that were not very large.

Your best performing plane blade is governed by the quality and carbon content of the steel,and by how well hardened and tempered it is. If everything isn't just right,high quality steel will not perform as well as it might. Poor hardening,decarbing,or poor tempering (too hard or too soft) can greatly affect the edge taking and holding ability of a blade.

[Noah Wagener]

So what do you make of the Japanese still laminating everything? I read that they even laminate chipbreakers.

My cast steel blades tend to round over fast. Is that an indication of being too soft? If i were to attempt to harden would i need to anneal first? Could you describe any differences in hardening and tempering for this type of steel compared to what you laid out for O1?


thanks

[Jessica Pierce-LaRose]

Well,a picture would have been very helpful. I was thinking about a much different style of nicker.

Sorry about that George! I didn't have my camera, and realized after my post, "I bet I wasn't very clear about what I meant", so tracked down that other thread with the picture, and inserted it in my first reply (to David) - I didn't realize that was *after* you already posted of, course!

So shoot for spring-temper, that's the answer to my question, good! Thanks so much; I appreciate the full-length instructions, too. Sorry to make you type it all out - I'm sure you've already done so here in the past.

I agree with you about working your own steel. It certainly opens up doors. I haven't done any on my own, although I sort of watched and learned and talked at a blacksmith fellow as he did so, and I've read enough from here and books and such, and seen it in videos from Larry Williams. I feel pretty confident in my ability to do so, or at least not destroy anything or injure myself in the process. I'd certainly rather pick up a torch and bricks and some O1 over grinding away at a plane blade.