Sharpening (sorry) 050 plane cutters.

[Honest John]

Took delivery today of my latest auction site purchase, a record 050 combination plane complete with its original 17 cutters. Pleased with the deal and the item seems complete and little used. I downloaded the record manual from the Cornish woodworking site that holds so much information on these devices. The manual states that the "straight cutters are sharpened like plane irons and present no problems". Later in the sharpening section I says that it is undesirable to have a secondary bevel, so to my mind that's not like my plane irons! On examinining my selection of cutters, non of them seem to have a secondary bevel. It is possible that most of them have never been used and are therefore as the manufacturer supplied them. I sharpened one straight cutter on my diamond stone using my Veritas guide set at 30 deg, which seemed to be the original angle. I polished this bevel and also the back on my strop and reassembled the plane. Whilst I still have a learning curve to climb up, this cut a rabbet very well and without the noise and dust I normally associate with this process. My issue now is that when I resharpen this cutter again I will have to cut the whole bevel again, rather than touch up a small secondary bevel as I would with my chisels or plane irons. What do other people do with combination plane cutters? I am tempted to just sharpen them like my place irons, that is with a short secondary bevel. Indeed my mk2 Veritas guide actually has an adjustment to do exactly this. I'm beginning to wonder if the "no secondary bevel" was intended to refer to the moulding cutters? This is a very specific sharpening query and so I hope it doesn't cause too much of the usual grief! Secondary bevel or not. What do you use?

 

[NickN]

I've only ever seen it recommended to use a 30 degree single bevel on most of these plough/combination plane straight cutters, but I also can't see why a 35-40 degree second bevel wouldn't work in a similar way to a standard plane. I believe Veritas actually do recommend a secondary on theirs, so it must be ok.
My Mitor plough cutters are all single bevel at the moment, but haven't had a chance to play around with it much yet.

 

[Jacob]

There's no particular point in a secondary bevel it's just part of the new sharpening ritual.
Small combi blades are much simpler done freehand - which usually results in a slightly convex bevel but that's OK as long as you keep the edge angle around 30º. A little and often. If you start fiddling with jigs and multiple bevels you are making work for yourself and will shorten the life of the blade.
When they wrote "straight cutters are sharpened like plane irons and present no problems" jigs weren't widely used, modern sharpening hadn't been invented, planes irons (and most things) were done freehand.

 

[undergroundhunter]

There's no particular point in a secondary bevel it's just part of the new sharpening ritual.
Small combi blades are much simpler done freehand - which usually results in a slightly convex bevel but that's OK as long as you keep the edge angle around 30º. A little and often. If you start fiddling with jigs and multiple bevels you are making work for yourself and will shorten the life of the blade.
When they wrote "straight cutters are sharpened like plane irons and present no problems" jigs weren't widely used, modern sharpening hadn't been invented, planes irons (and most things) were done freehand.

+1

 

[Paddy Roxburgh]

I tend to do a single bevel on my plough cutters, in fact all my planes and most of my chisels with the exception of mortise chisels, however if you are used to doing a secondary bevel then just do so on your plough irons, I can't see how the wood would know

 

[RobinBHM]

I would have thought you could sharpen to a 30 degree bevel, then when the cutter gets a bit dull, touch it up with a few strokes to get sharp again, honing basically at a slightly steeper angle. Regrind to a single bevel when needed.

 

[Jacob]

I would have thought you could sharpen to a 30 degree bevel, then when the cutter gets a bit dull, touch it up with a few strokes to get sharp again, honing basically at a slightly steeper angle. Regrind to a single bevel when needed.

This is against the oldest and most basic first rule and is really bad practice- it's called rounding over! :shock: :shock:

If you just hone the whole bevel there will never be any need to regrind, and in any case small blades are difficult to regrind (powered) as they overheat very quickly.

 

[Honest John]

Thanks to all for your replies. It seems a single bevel is the way to go. Thank you Jacob I'm going to give free hand sharpening a go as there is a number f cutters to sort and the metal of the cutters is quite thick (compared to my chissels) and I should be able to feel the bevel. If I can flatten and polish the backs the cutters should sharpen relatively easily. The profiled ones should present more of a challenge.

 

[Jacob]

..... If I can flatten and polish the backs the cutters should sharpen relatively easily. The profiled ones should present more of a challenge.

"flatten and polish the backs" is again just another feature of weird modern sharpening fashions. You can be sure that your "backs" (better known as "faces") are flat enough and don't need polishing beyond the tiny bit of work needed to take the burr off the face.
Save yourself a load of work!

 

[bugbear]

I sharpened one straight cutter on my diamond stone using my Veritas guide set at 30 deg, which seemed to be the original angle. I polished this bevel and also the back on my strop and reassembled the plane. Whilst I still have a learning curve to climb up, this cut a rabbet very well and without the noise and dust I normally associate with this process. My issue now is that when I resharpen this cutter again I will have to cut the whole bevel again...

Unless you're cutting an amazing number of rebates/grooves, the blade will not need sharpening very often. When it does, simply repeat the procedure you've already established. The widest blade is only 1/2", so you're removing very little metal, so it's quick and easy.

BugBear

 

[AndyT]

^^^ This!

 

[Droogs]

I use my Record 405 almost daily, as all my lippings are done by hand (too fear't of the router). In my experience the single 30ish deg is fine but I have found that on particularly gnarly grain a very small back bevel on the face of the iron helps tremendously. Also don't try to take too big a bite in one go.

As far as sharpening goes, I sharpen all the blades just as if they were a normal plane iron free hand but with a single bevel and then use slipstones and diamand files to sharpen the more intricate parts of the profile. To hone the bevel I use some MDF that has been shaped using the the Iron I want to sharpen and cover it with polishing compound. It takes a bit longer than a straight edge iron but hey ho.

 

[ED65]

My issue now is that when I resharpen this cutter again I will have to cut the whole bevel again, rather than touch up a small secondary bevel as I would with my chisels or plane irons.

Unless the cutter actually gets blunt blunt you can maintain the edge for a very long time by just stropping periodically. I kept one of my plane irons going this way for about six months, never had to take it to a stone until I wore the edge a lot during a single session working the edges of some chipboard.

I am tempted to just sharpen them like my place irons, that is with a short secondary bevel. Indeed my mk2 Veritas guide actually has an adjustment to do exactly this.

I think what you don't want to do is raise the honing angle significantly higher than 30°, and most freehand honing back in the day raised the angle of the edge by about 5° which might have caused a problem with performance. Of course if the mk2 can do your secondary bevel at 1-2° that shouldn't make any difference worth noting.

If you stick to convention and do a single flat bevel I don't see why it's a big issue though. That was the way they were always done going back to the days of much slower-cutting sharpening options.

 

[ED65]

There's no particular point in a secondary bevel it's just part of the new sharpening ritual.

I don't want to divert this thread but seriously Jacob? There are numerous books written before even you were born that detail creating a secondary bevel during honing and why you would choose to. It is by no means an aspect of new-fangled sharpening practice.

 

[Jacob]

There's no particular point in a secondary bevel it's just part of the new sharpening ritual.

I don't want to divert this thread but seriously Jacob? There are numerous books written before even you were born that detail creating a secondary bevel during honing and why you would choose to. It is by no means an aspect of new-fangled sharpening practice.

Be interested to see that.
As far as I am aware the terms themselves (primary, secondary bevel) only came into use recently. Calling the face "the back" is also recent.

The has always been the advice about grinding at 25º and honing at 30º but that's basically for novices to avoid rounding over. Once you've got the idea then "primary/secondary" bevels can safely be left behind.

 

[bugbear]

There's no particular point in a secondary bevel it's just part of the new sharpening ritual.

I don't want to divert this thread but seriously Jacob? There are numerous books written before even you were born that detail creating a secondary bevel during honing and why you would choose to. It is by no means an aspect of new-fangled sharpening practice.

This has been around the internet for National Poetry Day today:

"He Tells Her"

He tells her that the Earth is flat—
He knows the facts, and that is that.
In altercations fierce and long
She tries her best to prove him wrong.
But he has learned to argue well.
He calls her arguments unsound
And often asks her not to yell.
She cannot win. He stands his ground.

The planet goes on being round.

—Wendy Cope

 

[Sheffield Tony]

The 050C manual states a grinding angle of 35 degrees, no secondary bevel, if that helps.

 

[RobinBHM]

I would have thought you could sharpen to a 30 degree bevel, then when the cutter gets a bit dull, touch it up with a few strokes to get sharp again, honing basically at a slightly steeper angle. Regrind to a single bevel when needed.

This is against the oldest and most basic first rule and is really bad practice- it's called rounding over! :shock: :shock:

If you just hone the whole bevel there will never be any need to regrind, and in any case small blades are difficult to regrind (powered) as they overheat very quickly.

I thought it was called honing, not rounding off.....

Ive never understood this secondary bevel term, I always thought, grind first to the correct angle, then hone to slightly steeper angle.

If I had a tool that was losing its edge, Its natural to hone with a few strokes and back to work. I agree if blades are very small then just hone at a single bevel.

 

[RobinBHM]

..... If I can flatten and polish the backs the cutters should sharpen relatively easily. The profiled ones should present more of a challenge.

"flatten and polish the backs" is again just another feature of weird modern sharpening fashions. You can be sure that your "backs" (better known as "faces") are flat enough and don't need polishing beyond the tiny bit of work needed to take the burr off the face.
Save yourself a load of work!

Polishing the back seems a logical approach to me.

The sharpest edge is achieved by 2 edges being abraded to the finest possible grit, so under a microscope the edge has the smallest number of fractures possible.

Polishing the back takes out the tools grinding marks reducing imperfections on that face so each time the tool is sharpened the edge is achieving two smooth faces.

Of course its true that only the few microns of the back nearest to the edge are involved in the sharpness of that edge, but to polish that part only risks rounding over the edge.

 

[Phil Pascoe]

Polishing? A bit extreme maybe, but flattening certainly. The sharp edge is the intersection of the back and the front, so it's sense to make sure they are both at least straight - unless you want a serrated edge chisel.
Calling the face "the back" is also recent? How recent? - it was the back when I started school fifty years ago.