Length of the Krenov polishing plane

[Ron Kellison]

I've been toying with the idea of building a small Krenov-style polishing plane with a 1 1/2" iron. I've never seen any measurements for his famous little plane but it looks like it's somewhere around 6" in length. I've got an opportunity to get a couple of cocobolo blanks but they are only 12" long. If I'm very, very, very careful can I get two blanks out of a 3" x 3" x 12" blank?

Regards,

Ron

[Casey Gooding]

Six inches would be fine for a small plane. Just cut the 12" blank in half and go for it.

[Jim Belair]

Hi Ron

If you are making the plane by sawing the cheeks off and then reattaching, normally an extra inch is needed at each end for positioning dowels. These aid in realignment for reassembly of the sawed blank and get cut off after glue up. That's the way I've made this style of plane anyway. So you wouldn't be able to get two 6 inch planes from a 12 inch blank.

Others may take a different approach.

Jim B

[Pam Niedermayer]

...If I'm very, very, very careful can I get two blanks out of a 3" x 3" x 12" blank?

If you mortise rather than saw and recombine, you could get two 6" planes from your block. It's not too much work to do this in a small plane, just be sure to make the mouth very thin (for a polishing plane).

Pam

[Mark Baldwin III]

I leave the alignment pins in. I like the look of 'em.

[Steve knight]

I would not use cocobolo if I were you. oily woods have had the most failures in my plane making business. it also does not glue worth much of anything.
if you wanted to sue it I would do all of the cutting then let it set for several months.

[Tom Vanzant]

1+ on what Steve said. Pam's suggestion to mortise instead of laminate will eliminate the glue problem.

[Ron Kellison]

If you mortise rather than saw and recombine, you could get two 6" planes from your block. It's not too much work to do this in a of small plane, just be sure to make the mouth very thin (for a polishing plane).

Pam

Hmm...mortising cocobolo. That would certainly be a challenge! It would be a great test of my new Narex mortise chisels! I've also got a few long handled Japanese paring chisels that might be useful. Let me think on it awhile longer, eh?

[Pam Niedermayer]

Hmm...mortising cocobolo. That would certainly be a challenge! It would be a great test of my new Narex mortise chisels! I've also got a few long handled Japanese paring chisels that might be useful. Let me think on it awhile longer, eh?

Think as long as you want, I have no skin in this game. :) However, I was thinking this morning that even if you lost an inch to the Krenov process, how bad would that be? Not that much difference between a 6" smoother and a 5" smoother.

Pam

[Jessica Pierce-LaRose]

If you do want to glue cocobolo, I've had good luck with "Smith All Wood Epoxy" (I ordered mine from LMI) when using it for guitars. However, I'd still take Steve's advice over mine. He certainly has more experience than I! (I think I've just been very lucky with those two guitars - there's a lot of things that shouldn't have worked on them... )

[Bob Winter]

I've been toying with the idea of building a small Krenov-style polishing plane with a 1 1/2" iron. I've never seen any measurements for his famous little plane but it looks like it's somewhere around 6" in length. I've got an opportunity to get a couple of cocobolo blanks but they are only 12" long. If I'm very, very, very careful can I get two blanks out of a 3" x 3" x 12" blank?

Regards,

Ron

Not sure about the length of his famous small smoother. I do have 2 of his smoothers he made after he stopped making cabinets. Lengths are 6 3/4 inches and 7 7/8 inches.

[Matt Evans]

my two cents. . .

Make a thicker chisel out an old file if you plan on morticing. Unless the Narex chisels are a lot thicker than I am thinking they are, you want a heavy duty chisel to remove the waste. Particularly in a hard wood. You could still use a dowel for the wedge, to simplify it, but the morticed plane might work out better for you in cocobolo.

[David Dalzell]

Well I have made a Krenov smoother (8" long with a 2" blade @ 60 deg bed angle) using purpleheart and gluing with Titebond II. So far no problems with glue and it shaves fantastically. However I am about to make three more Krenov planes planes (jointer, jack, and smoother with a different bed angle). I will be using an old rosewood plank that was given to me. Being concerned about gluing oily wood I did a little research into appropriate glues. After web research and discussions with several technicians at different glue companies I settled on West System G/Flex 655-K epoxy. It is engineered for (among other uses) gluing oily tropical woods. It is quite expensive though, $35.00 for the two 4.5 oz tubes. I haven't used it yet. I have to wait until the weather warms up a bit more.

[Jessica Pierce-LaRose]

my two cents. . .

Make a thicker chisel out an old file if you plan on morticing. Unless the Narex chisels are a lot thicker than I am thinking they are, you want a heavy duty chisel to remove the waste. Particularly in a hard wood. You could still use a dowel for the wedge, to simplify it, but the morticed plane might work out better for you in cocobolo.


I have the Narex mortise chisel set LV was selling on sale a while back (my wife surprised me by buying them when I mentioned off hand it was a decent deal for something I had been looking for) I've used them for chopping mortises in some pretty tough domestic oak and hard maple, and they've held up quite well. I haven't done true mortises in any exotic stuff, but one of the first things I tried with them was heavy chopping in some paduak and cocobolo scraps I had, and they've worked well enough. I'm sure something better would be nicer, but I'm quite thrilled with 'em.

They're about 3/4" inch on the round section where it attaches to the handle, (almost looks like they were milled out of round stock?) and the thickness starts at about a 1/2" at the handle end after that round turns into the shaft, tapering to about 3/8" just before the bevel starts. They're trapezoidal in profile like a proper pigsticker is; they're not quite as heavy duty as a true "pigsticker" style, but they certainly aren't the simple, unbeveled firmer chisels that get sold as mortise chisels some places.

[Roderick Gentry]

I normally built Krenov planes without much attention to his specific lengths, with the exception of once building one of his 18" jointers. He worked on a small scale, and with his own hands, and I alway preferred to make custom stuff rather than reproduction stuff, though both are equally interesting. I liked to make Krenov planes with the mouth on the center of length, roughly, so mine tended to be a little longer.

I'm not a fan of tropical woods for planes, particularly not toxic ones, but I think you should be able to glue it, lots of guitars are made of coco. Wash it with acetone and glue it with epoxy, maybe rough sand it first. I had a little look at the usual guitar sites and found instruction for pretty much every glue, so there seems to be some forgiveness. One guy tested all the glue we normally use, and the only one that failed repeatedly was Gorilla, which I don't use for the most part anyway.

With Krenov planes sweat the crosspin details, and wedge details, that is usually the biggest problem. If built as designed the planes work pretty well, but otherwise they can clog a fair bit. I tend to do a slightly Japanese mount with a vertical sction above, but then it lays off more than usual. I have a little jig that consists of plywood patterns for the wedge, and pin offset.

College of the redwoods has plans online, but I haven't checked them against the book or tape. Ok had a little look - exercise care...

[Ron Kellison]

Thanks to all for the replies! I have some real clear, straight grain 3x hard maple blanks (originally for baseball bats) that I will use as an experiment before I start cutting the cocobolo. I now also plan to try to make a small plane just by mortising before I tackle the REALLY hard wood. This should be fun and keep me busy for a few months! Thanks again!

Regards,

Ron

[Terry Beadle]

If you decide to hand mortice, I would recommend you remove the main volume of the mouth via a drill press and an end mill. Hand morticing cocobolo is a real challenge. Be prepared to resharpen a lot !

I have one of Steve Knights razee jack planes in cocobolo. I've used it for several years now and it's one of my prized tools. No separations detected and the plane is a pleasure to use. What ever glue and procedure prep he used is still doing good work.

I think you are smart to experiment with rock maple. I've made a couple planes out of it and they all work great, the maple was very predictable and so far has been very stable. I also like Japanese planes. The planes are made from aged oak and the best is red oak ( aka hon oak ). Oak is very tough, has little or no compression and the Japanese picked it because of it's predictable nature. Using Cocobolo or other exotics is always a beautiful idea to me until you get down to the brass tacks. Purple heart will machine well but it will also fight you tooth and nail in a chiseling of any large areas. It can crap out on you just like southern yellow pine. I had good success with purple heart for a laminated sole with an adjustable dove tailed sliding mouth. Cocobolo, IMO, is even harder to deal with.

So I would use the exotics to decorate a plane but avoid them for the main body and sole ( soul ...hoot! ) A jazz tune comes to mind.

Good luck, keep us posted and enjoy the shavings !

[Pam Niedermayer]

...I also like Japanese planes. The planes are made from aged oak and the best is red oak ( aka hon oak ). Oak is very tough, has little or no compression and the Japanese picked it because of it's predictable nature. Using Cocobolo or other exotics is always a beautiful idea to me until you get down to the brass tacks. Purple heart will machine well but it will also fight you tooth and nail in a chiseling of any large areas. It can crap out on you just like southern yellow pine. I had good success with purple heart for a laminated sole with an adjustable dove tailed sliding mouth. Cocobolo, IMO, is even harder to deal with....

Terry, I don't know that there is any wood all that much harder than hon red oak. It makes for great, stable dai that don't take all that much more time and effort to mortise than white oak (kashi), which took me about a half day to mortise for my first dai, much less time now. It's not a bad idea to drill the mouth opening straight up from the sole, but that's mostly to avoid placement errors when chiseling down from the top.

Pam