Chris Schwarz's Blog

Sharpen a Fore Plane

The fore plane is a traditional English tool used to get rough boards fairly flat so that you can then make them really flat with a jointer plane and ready to finish with a smoothing plane, scrapers and (sometimes) sandpaper.

Fore planes are supposed to be about 14″ to 18″ long. If you want to use an old metal plane as a fore plane, a No. 5 jack plane or No. 6 fore plane would be a good choice. I use a Hock Tools A2-steel replacement blade in my fore plane. A2 is a little harder to sharpen for me, but this modern steel takes a heck of a beating before it gives up, so it’s perfect for a fore plane. I also have a couple wooden-bodied fore planes that are nice because their light weight makes them less tiring to use.

Fore planes are supposed to have a curved cutting edge and are used directly across and diagonal to the grain of your board. Most people understand the idea of working across the grain (it allows you to take a deeper cut without tear-out). But many people are flummoxed by sharpening the curve on the edge. In fact, I’ve had about a half dozen readers send me their irons and ask me to do it for them.

Because I don’t want to open a sharpening service, here is how I grind and hone the curved edge of a fore plane’s iron. It’s a simple process. And if you take your time the first time you do it, I know that you will succeed.

This week I noticed that the edge of my metal fore plane was chipped up and the tool was getting quite hard to push. It was time to grind and hone a fresh edge. The first thing to do is mark the shape of the curve on the iron so I can replicate that shape. I use a curve that is an 8″ radius. I’ve experimented with lots of curves between 10″ and 6″ radii. I like 8″.

I have a wooden template that is the same width as my iron and has the curve shaped on one end. I place the template on flat face of the iron and mark the curve with an “extra fine” point Sharpie.

Place the template on your iron and trace its edge on your iron. A thin, consistent line is best.

Then I go to my grinder to remove all the nasty chipped-up metal. I keep my grinder’s stock tool rest set to always grind a 25Ã?° bevel. I don’t futz around with the tool rest. The first thing to do is to grind away the excess metal right up to your marked curve. This is done with the iron at 90Ã?° to the stone. I just balance the iron on the tool rest and go to town.

Grinding at 90�° to the stone removes metal quickly to the shape you want and it creates a small flat on the edge of your iron. This is a good thing. The flat helps prevent your steel from overheating while you grind away the bevel at 25�°. Thin steel heats up really quickly.

Hold the iron 90�° to the wheel and show the edge to the iron. Remove all the steel right up to your Sharpie line. The first time you do this, take your time. It gets easy real quick.

When you get to the Sharpie line, put the iron flat on your tool rest and start grinding the bevel until the flat spot on the end is almost , repeat almost , gone. You remove the last little whisker of the flat on the sharpening stones.

Start by showing the middle of the iron to the grinder wheel. You’ll feel when the bevel is flat on the stone. Then sweep the iron right to grind up to the left corner. Try to keep the bevel in full contact with the wheel the entire time. Then repeat this process and sweep left.

Continue to grind and watch the flat shrink. Don’t use a lot of pressure when applying the iron to the wheel or you will cook your edge (it will get black).

Show the center of the iron to the wheel and sweep left or right. Here I’m sweeping right to grind to the left corner.

Here is my completed edge, ready for honing.

Here is the flat left on the tip of that edge. The reflection makes it look bigger than it really is. It’s a little less than 1/64″.

You can then hone the edge freehand. The edge doesn’t have to be perfect because the fore plane never produces a finished surface. However, you can use your cheap little side-clamp honing guide to help you (and your edge will look a lot sweeter, as well).

Put the iron in your honing guide and set the iron to hone a 30Ã?° secondary bevel. Place the iron on your coarse stone (#1,000-grit or coarser if you’ve got it). Put finger pressure hard on one corner of the iron and press that to the stone. Pull the guide toward you and shift your pressure to the other corner. This will feel awkward at first. But eventually you’ll rock it smoothly and naturally.

Repeat this process by starting with all your finger pressure on the other corner. If you are doing this correctly you should see an X-shape appear on your stone. Then it’s just like sharpening any tool.

Rock the edge back and forth as you move the jig. This might look hard. It’s not. It also tends to shape the wheel of your honing guide into a slight barrel shape , which is a good thing.

Remove the flat bit on the end of the iron , you’ll know it’s gone when you can feel a burr on the other face of the iron. Then move up the grits until you run out of grits or patience.

Now reassemble your chipbreaker and your plane. Sight down the sole of the plane and tweak the lateral-adjustment lever until the curve of the iron is in the center of the sole. This is easy to see.

When you are done sharpening you should have a nice even secondary bevel.

Then work directly across the grain of a board. Increase the projection of the iron until you are removing material quickly and can easily push the plane. The shavings should be thick , I shoot for 1/32″-thick with most woods.

You can probably take a larger shaving in a softwood, but I usually poop out if I try to take a shaving thicker than 1/32″ , but yet, that’s a lot of material for one stroke of a plane.

The fore plane is really useful for me, even though I have a nice powered planing machine. It allows me to remove material in a localized area with ease or to peel the edge off a rough board faster than my jointer (because I can work only the high spots). And it allows me to flatten boards and panels that are too wide for my jointer and planer.   

- Christopher Schwarz

24 thoughts on “Sharpen a Fore Plane

  1. Christopher Schwarz

    David,

    The names of planes are confusing. It depends on the culture and the time of the writer/tool manufacturer.

    The fore plane is always a roughing plane and it appears first in the historical record.

    The jack plane appears later. And it has many uses, including: an all-around carpenter’s plane, as a roughing plane, as a short jointing plane, as a long smoothing plane, as a plane used on a shooting board.

    So a jack plane can be a roughing plane, and you could rightly call it a fore plane then.

    However, you can’t really call a fore plane a jack plane — because it has so many other recorded uses.

    Bottom line: You can call it whatever you like and be basically correct. But if you want to make a roughing plane that works like the historical example, use a Stanley No. 5 or No. 6 because they are the correct length.

    I hope this helps (and doesn’t make it works).

    Chris

  2. David

    Chris – Could you comment on the differences/usage of a fore and jack plane? I’ve seen historical references to the progression of fore:jointer:smooth plane in dressing raw lumber, as well as jack:jointer: smooth plane. It would appear from Stanley’s bench plane line-up that a Jack plane is usually the #5 size, while a fore plane is the #6. There seems to be an equivalent progression in wooden planes. For example, the 1872 Greenfield catalog lists jointers, fores, jacks, and smooth planes, and also offered a set for sale consisting of a miter, jointer, fore, jack and smooth plane (all for the low price of $6.50!).

    David in Raleigh NC

  3. Christopher Schwarz

    Jason,

    A jack can be configured many ways, including the two you suggest. Also, I keep a dead straight iron in my bevel-up jack for shooting, at which it excels.

    Chris

  4. Jason

    I recently bought a BU jack, and was debating whether I should grind the blade into a curve. After reading the comments, it seems to me that a BU jack is more like a big smoother or a small jointer than a foreplane. Yes/no?

    Thanks!

  5. Michael L. Dyer

    Hi,
    I went right down stairs and tried it on a board that I was planning to straighten on the jointer after lunch.
    Fortunately, I had an old iron for my #4 that wasn’t doing anything, so I shaped and honed the blade, loaded it into the #4 and rough jointed the stock in a thrice – cleaned it up with few strokes with a smooth plane and off to the table saw – worked like a charm.
    Thanks,
    Mike

  6. James Watriss

    I’m sure that, in theory, it’s possible to wrangle a bevel up plane into working well enough as a fore plane. But a) you’d have to regrind the bevel to approximate a 45, and b) you’d then have to add a camber, and then sharpen, in the hopes that it will act the way you want it to. Or at least act in a way that’s desirable. You’re right, higher angles are great for reducing tear out… and harder to push.

    I think Chris made a great point. Don’t get me wrong, I love my bevel up Jack, and I went with extra blades, ground to different angles. And I’m sure I could convince it to do something like this. But I think that there’s a limit to just how many things I want to try to teach this plane to do. The bevel up craze only goes so far, and there’s more to life than overgrown block planes.

    Between the cost of an extra iron (unless you want to grind back and forth. ugh!) and the cost of time invested, I’m not sure that the savings over an old #5 still exists. There are so many old jack planes on ebay, and they go for so little, that I think it’s worth getting a regular plane, and fettling it properly.

  7. Ethan Sincox

    Chris,

    A fortuitous blog! Just last night, I was taking inventory of what I’ll need to start working on my own Holtzapffel bench (thank Dave Pearce for that inspiration). Right off the bat, I realized I had never gotten around to cleaning up a pre-WWII #6 I picked up for a good price because it was missing the plane iron cap.

    Tomorrow sounds like a great day to run down to Woodcraft and pick up a Hock blade/chip breaker and get started on bringing that plane back to life!

    And now I know how to get the blade set up right, too.

  8. Adrian

    Regarding the angle of cut with a bevel up plane, it is going to depend on how you sharpen the blade. In principle you could sharpen a uniform bevel angle. But if you sharpen with a guide as Chris suggested, you will get a higher angle at the edges. How much higher depends on the size of the guide’s wheel. If you use a honing guide that elevates the back of the blade by 1 inch and you sharpened your bevel up blade to achieve a 45 degree cut angle in the center you’d get about a 50 degree cut angle at the corners.

    Generally a higher angle is said to REDUCE tear out (though you’re not suppose to care about that for a fore plane) but at the cost of being more difficult to push. More difficult to push could be a big disadvantage here.

  9. joel

    Chris,
    I think a bunch of years ago you and I had this discussion. My favorite fore plane is my English Panel planes (and the infill panel planes were invented before the infill smoother because IMHO they get a huge workout in any shop hand milling wood) but anyway you suggested try a 5 1/2 – not as a replacement for an infill but a similar size and similar function and more common – any reason you didn’t mention the 5 1/2 here? oversight or you had a reason?

  10. Christopher Schwarz

    James,

    Thanks for posting that.

    I have never used a bevel-up plane for a really deep cut like this. The reason being that I save my money for premium planes on tools that require more precision than a fore.

    I would really like to hear feedback from people who have done this.

    Totally ignorant outside Cincinnati,

    Chris

  11. Eric

    I was about to ask what the difference is between a fore plane and a scrub plane, but a little googling showed that you’ve already addressed that topic elsewhere. So thanks for that! I’m looking to get a first-pass plane since I don’t have a planer or jointer, so now I am better informed on what to look for.

  12. James Watriss

    Odd thoughts…

    -On radius for a bevel up plane:

    The 8" radius template works on the back of the bevel down iron… in other words, it works on a surface that is held at a 45 degree angle to the surface.

    The ugly dirty way to transfer this to a BU plane, without using math, would be to trace the radius on something like the sharp edge of a shingle, and trace that on the BEVEL of the iron. With 12 degrees in the bed, 25-30 in the iron, the angle in the shingle should be a fairly decent match. Of course, you can always make a wedge for that last 5-10 degrees, to make sure you’re tracing the radius at a 45 degree angle to what will be the surface of the wood. It’s possible that the math works out, and that a 2.5" radius is the ticket… but that sounds a bit extreme to me.

    One reason I can think of to not use a bevel up plane this way is that the iron will be working a lot differently. On a scrub or fore plane, the back of the iron will always meet the wood at the same approach angle. (45) Grinding a radiused iron for a BU plane is different, since it’s the radiused bevel that’s meeting the wood, not the flat back. It will be meeting the wood at different approach angles along the edge due to the way the blade is ground. And if I’m visualizing it right, it means you’d be getting a steeper angle at the edges. It might not be a noticeable difference. Or, maybe it’ll tear more… hard to gauge. And you’re right… it’s a lot of metal to waste away, especially if it won’t work as easily, or as well.

    -On grinding for the lurking new guys… Having recently taught this class myself, I was reminded that it’s pretty terrifying for beginners to grind their treasured tools for the first time. If you’re really worried, find a junky iron for a couple o bucks at a flea market to practice on, and go for it. Keep your fingers as close to the edge as you dare, and feel the heat of the iron as you grind. My rule of thumb… er, finger… if it’s too hot for your fingers, it’s too hot for the iron.

    This is probably the best blade profile to learn to grind on, too. The corners are the most likely to get cooked, and they’re the least likely part of the iron to get used when you’re hogging out wood.

    -Sorry to come out as the class know-it-all.

  13. Christopher Schwarz

    Gus,

    The pressure during honing is there to rock the guide over onto the edge of its wheel. If you hone without a guide, extra pressure is unnecessary. If you hone with a guide, you have to rock the sucker a bit to make the edge touch the stone.

    Hope this clears things up. If not, just holler.

    Chris

  14. Christopher Schwarz

    Gus,

    The pressure during honing is there to rock the guide over onto the edge of its wheel. If you hone without a guide, extra pressure is unnecessary. If you hone with a guide, you have to rock the sucker a bit to make the edge touch the stone.

    Hope this clears things up. If not, just holler.

    Chris

  15. Gus Gianakopoulos

    I don’t quite follow your method. You created the 8" curvature on the blade and flattened the primary bevel using the grinder. So then why is it necessary during honing the secondary bevel, to apply pressure on either side again? The secondary bevel will be created at a consistent rate across the curvature when applying pressure equally across the blade.

  16. Chris C

    The best part about using a fore plane(or any plane for
    that matter) is that if you happen to get the urge to
    flatten some stock at 2am, you won’t wake up the
    family!

    Chris

  17. Adrian

    I was thinking of preparing a blade to use for this purpose in my Veritas Bevel Up Jack plane. Since this plane is bevel up and bedded at a lower angle, a much larger curve is required to give the same cutting behavior.

    It appears from a quick calculation that an 8" radius on a plane with a 45 degree bedding angle will match the performance of a 2.5" radius on a plane bedded at 12 degrees. Is there any reason not to use a bevel up plane prepared this way? It’s a lot of metal to remove to establish that curve.

    Note that for a 2.25" blade, the 8" radius makes the crown of the blade 0.08" (bit over 1/16") higher than the edge. The 2.5 inch radius makes the crown 0.27" higher.

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