Thread: Sharpening Router Plane Blades

Hi Graeme

I would add to this: I think it is a great method and endorse it, with credit to Derek.

But an alternative, particularly on vintage blades, is lapping and polishing the top bevel (if you can), and re-sharpening and honing the underside only, using the router plane itself as a very effective jig.

There is a Paul Sellers' video on this although he focuses on it as a method of fixing the geometry of the blade - essentially one puts masking tape on the base of the router, inserts the blade, lower the blade until it just "kisses" a sharpening stone and then lap the blade on a stone. The tape (assuming it has a consistent thickness) avoids abrading parts of the sole. (While you want the sole flat, if it's not hitting all edges of the stone it could make a flat sole uneven. It woudl also make the process enormously slower as the entire sole would be getting lapped).

This does two things - provided the stone is dead flat, guarantees that the blade will be flat across the cut, and also lightly abrades the edge. Secondly, if the top face is flat and smooth, it should give you a nicely honed edge to the degree at which you've abraded it back from the other side.

An advantage of this is that if you have a vintage blade the underside might be a mess, but this method means you just correct it as you go with each sharpen as you will have a tiny ribbon of polishing underside. Not really an advantage with a replacement Veritas blade which is optimally lapped out of the box...

What I now do is just do is be a little fussy to get a smooth top-side face (a once-ever job), then the re-sharpening ever after is just using a high-grit diamond stone (to ensure it is flat), then superhigh grit (8,000 or 16,000) grit ceramic stone on the underside with the blade in and the tape on the base. This is really no different to when you flatten and smooth the back of a chisel or plane iron and then only work the bevel to sharpen.

An practical advantage, albeit modest, is you dont even really need to remove the blade before and after. Just rip off the tape and keep going. If you're as clumsy as I am, removing and re-inserting those blades is good to avoid! If you have a gently side to side lapping motion there shouldn't be a burr to remove.

Chris

Is this the video by Paul Sellers that you were refering to, Chris?
How to Sharpen a Router Plane | Paul Sellers - YouTube

Buy Paul, being Paul, also has a different method using diamond files:
Sharpening Router Cutters By Hand—Simple Works Best - Paul Sellers' Blog

And, of course, Derek also explained his technique on his website:
https://www.inthewoodshop.com/Woodwo...aneBlades.html

Paul's first method looks like a great technique for the initial fettling of a "new" (to me) router plane blade. For subsequent sharpenings you could use either Paul diamond file or Derek's method.

That's it, Graeme - around the 9:00 minute mark from the first one.

I just grab some tape from a drawer, tape the sole, go at it on a ceramic stone. Once you had a sliver of bright metal all the way across you're done. Tape off and keep going.

I think Derek's method is objectively superior, I should add.

Although I should add that another reason I don't use it is that I have a Bosch PBD drill press which is a great little unit, but I wouldn't really trust it and the table it comes with to provide a perfectly perpendicular grind on the sanding stick (particularly with a little lateral pressure from the grind). Not because I don't think they're well manufactured, but just the limited mass.

Thanks for the heads up, Graeme.

And thanks Chris for the video to Paul Sellers. I have been aware of his sharpening method here for a while, but not seen this video. I have used his sharpening method for my Western mortice chisels (not the Japanese ones).

Do you wonder that Paul Sellers always seems to start with a fix for a problem that only he ever has noticed? In any event, his fix for an out-of-perpendicular iron is a good one ... just that I never have come across the need to do this. It certainly can occur with any router plane - vintage is more likely, since a new router plane would simply be sent back to the Seller.

The poor condition of the blade is not atypical of vintage router plane blades - sharpening these is tricky as many struggle to hold the blades flat on a stone. That was a reason I came up with the method in the video by Vic. The hollow acts like a honing guide and offers control.

Incidentally, there is another method, advocated by Chris Schwarz, where he adds a back bevel. The danger here is reducing the relief angle, something which Paul mentioned.

One issue I have with Paul's sharpening method is similar to the criticism levied at his round bevel method. It is not that the method(s) do not work - clearly they do, since he does excellent work with his blades. The issue is that many cannot control the angle of the bevel. In his router plane method, he looks to be adding a bevel in the region of 40-45 degrees. That is not going to stay "sharp" for long, and will cause tearout if planing across our Aussie hardwoods (dados and tenons require a cross grain cut). The other issue is that he does not take the edge up to a higher grit. I suspect that he is influenced by his desire to keep sharpening cheap.

The aim of the hollow grind is to keep the desired bevel angle (around 25-30 degrees), with the hollow reducing the area of steel to remove - much like creating a micro bevel. Start with a new blade, and this is going to provide excellent results for a long time. Once the hollow is done, touch ups are a simple affair and do not rely on anything other than the sharpening stones.

Incidentally Chris, I started this technique several years ago, when my drill press was a cheap Carbatec Taiwanese machine. It really does not demand much beyond a spinning wheel.

Regards from Perth

Derek

Thanks Derek

I suspect you're right about the drill press - and I know it's probably not critical but just superstition on my part!

I agree that polishing the top is difficult. I have found the best method for me is clutching a stone against your body so that you are very sensitive to any movement and can feel any loss of even downward pressure, and essentially just being very, very careful. A little hard to describe and awkward looking. The sort of thing you wouldn't want your wife walking in and seeing, in case it led to speculation about feelings towards abrasive materials on plates.

(In truth, it's the router plane she has to worry about...)

Just freehand grind the blades (no need for jigs or anything of the sort, just freehand them at a shallower angle than the final hone) and hone the tip. Do as little as possible in terms of faffing with the honing, just get it done enough that the edge has the strength not to crumble.

One of the big offputting things when you start this hobby as a beginner is the thought that everything takes some kind of independent process that's not mostly hand and eye. Skew blades, narrow chisels, chisels with a triangular top, router plane blades, small cutters.

All of it should be a grind and a hone, same basic idea. The grind is either a lower angle, or the pressure is biased when honing toward the tip if using the same angle. The less work you do honing and the more you focus it toward the tip of the tool, the higher the success rate and the lower the need for jigs, etc. If it gets confusing with extra steps, then grind keeping the honed bit as small as possible, lift just off of the grind and use a single stone and strop off the burr.

With vic's method, now the drill press is tied up with a drum that you may not have had, and you have to build some fixture to lay the blade on. You have to store that crap somewhere and find it later if you're not using it for something else. Most of what we see from someone like Vic is a kind of altered reality where the bulk of time is spent running around demonstrating tools and not getting anything made or done.

If you instead build hand and eye and separate learning about what needs to be done neatly and what doesn't, you end up with one way to grind things (generally a power grinder) and one way to hone them (rubbing a tool on a stone and maybe two). There's a good reason that even with the fine tools, you don't see really prissy machinist-looking grinds on the blades - it's not productive. Even on a tool that was obviously put away by someone skilled 100 years ago or set up once and almost never used.

Thanks David,

I was your classic catch when I started woodworking two years ago. Bought the Veritas honing jig and all the attachments and had a drawer full of sharpening equipment before I had even really done much of anything.

On a tangent, I bought myself a mini-lathe over Xmas. I am not intending on becoming a serious turner but wanted to just be able to do replacement tool handles, knobs and small parts. In a similar vein I just picked up one of the basic packs of no-brand HSS lathe tools.

I am quite time-poor. I could see some people turn full-time. My "shop" is full of regular woodworking tools. I vowed I was not going to fill drawers full of turning tools and jigs lying around everywhere until I knew I needed it. I wanted to just do functional turning.

I also had very limited spare time over Xmas. It was family holiday time with young family. I had time at nights for reading and research but limited time when a machine could be on.

So given the tools were cheap, and that I would probably upgrade if the hobby continued, I decided to just cross my fingers and freehand grind all the tools (save that I did not use a CBN wheel on the gouges, for fear of doing too much too quickly) and freehand honed everything. For the inside of gouges I didn't hand a rounded hone so just folded a piece of cork rubber lying around, charged with a little green crayon.

Within 20 minutes of just freehanding the gouge on the stone wheel on the tormek and then the leather wheel, without a jig, and freehanding the skew chisel on the CBN wheel then honing with a diamond paddle, I was off and going on the lathe with shavings flying.

That night I watched a Youtube video involving the tormek jigs (which I had bought). It was astonishingly fussy. They even recommended using the setup guide and jig to hone on the leather wheel to ensure accuracy. I'm sure it would have looked beautiful and did in the video.

If I'd watched all the videos and followed them, I might have assumed it was all necessary in order to get sharp. But because I'd (for example) just freehanded the gouge with no fuss, following the original geometry which seemed fine, and it worked well, I knew it wasn't necessary.

In all I think I spent 20 minutes tops setting up all the tools and getting them sharp enough for good results. It would have taken at least an hour to put them all in the correct jigs and grind them back to defined geometries and hone in a guide. They would have been beautiful but I wouldn't have gotten any turning done.

I suppose this is a long way of saying that when I went into the exercise wanting to spend the minimum time and without buying/making stuff I had no room for - unexpectedly the results were great and left nothing to be desired. Because I think I have gotten reasonable/intermediate at sharpening plane irons and chisels et cetera I knew what to be aiming for (and in particular, to be only bothered about chasing a super-polished surface at the cutting edge).

Chris

Originally Posted by D.W.

Just freehand grind the blades (no need for jigs or anything of the sort, just freehand them at a shallower angle than the final hone) and hone the tip. Do as little as possible in terms of faffing with the honing, just get it done enough that the edge has the strength not to crumble.

... With vic's method, now the drill press is tied up with a drum that you may not have had, and you have to build some fixture to lay the blade on. You have to store that crap somewhere and find it later if you're not using it for something else. Most of what we see from someone like Vic is a kind of altered reality where the bulk of time is spent running around demonstrating tools and not getting anything made or done.

....

David .. David ...

I used to do this - just freehand on the original face - for years and years. It was not very successful. For a start, much of the work done by a router plane is across the grain. This is best with a low cutting angle. Secondary bevels are higher than the primary bevel (by definition). Further, keeping the angle consistent leads to efficient sharpening.

A hollow grind lasts a long, long time. The hollow is the jig - not the wheel to create the hollow. Storage? How many sharpening stones do you have? 100 .. 200? Where do you store them?

Incidentally, this is not Vic's method. He simply made a video of my method.

Regards from Perth

Derek

I also started oppsite, trying to figure out how to jig the router plane blade, but ended up going the opposite direction. Separate the grind and the hone, just like chisels - if the hone angle and the grind angle get too close together, then shallow the grind angle.

I never tried to hone the entire face of the router plane blade, it's a waste of effort.

Originally Posted by Cgcc

Thanks David,

I was your classic catch when I started woodworking two years ago. Bought the Veritas honing jig and all the attachments and had a drawer full of sharpening equipment before I had even really done much of anything.

Fortunately or unfortunately, that's all of us. I have stone cones, two different tormeks in my past (one generic, one supergrind 2k real one), three different tormek wheels, two different 1x42 belt grinders (thinking they'd double for honing and small toolmaking - no chance on the latter - ho hum for honing).

Had both generations of the veritas honing guides and finally realized they were all a pain to use (and yes, the tormek tools are notoriously fussy and the leather wheel is almost useless for honing). Managing each specific problem with a prescriptive solution makes it difficult to solve other problems.