Woodworking Tip of the Day: Flattening Your Sharpening Stones: Pencil Grid, Lapping Plate and How Often

Not for nuthin'…. But….. the sharpest-looking set of stones in a lot of shops is also the reason the chisels won't pare a clean shaving. Waterstones wear every time you use them, and they wear the most right in the middle. Nobody notices until the plane iron comes off the stone with a rounded edge and a back that won't lap flat. I've got a dory's worth of bevels, gains and frames to cut this winter, so I went back to the stone makers' own instructions and the Fine Woodworking and Popular Woodworking articles and wrote down how I keep mine flat.

Why it matters: A waterstone cuts fast because its binder lets go and keeps exposing fresh abrasive. The price is that it dishes. Shapton says it plainly: the blade hits the middle of the stone more often, so the stone goes concave, and that makes for uneven sharpening. Tom Caspar wrote in Popular Woodworking that the wear "produces an undesirable curved edge on chisels and plane irons." It's worse on the back of a blade. Lay a flat back on a hollow stone and it only touches the high ends, so lapping it there rounds it over instead of flattening it. Paul Sellers' answer to that problem is to lap backs on something that stays flat, like a diamond plate or thick glass. A sharp edge is where two faces meet, and a dished stone spoils both of them.

Oilstones vs. waterstones: Norton says its oilstones (benchstones) "typically do not require flattening with normal use" because they're hard, but after years of steady use they can dish in the spots where you bear down the most. Waterstones are the other way around: they dish easily, but they're quick to bring back. Same job, different schedule.

Materials

• Your sharpening stones, every grit (not just the coarse one)
• A soft pencil
• Water, plus a tub or a sink without a garbage disposal (DMT says the slurry is hard on disposal bearings)
• Rags and a stiff nylon brush for cleanup

Tools: pick one flattener

• Diamond lapping plate. The DMT Dia-Flat (DMT is out of Marlborough, Mass.) is 10" × 4", ground flat to ±0.0005", and comes in 120 micron for stones of 1000 grit and coarser or 95 micron for finer stones. An Atoma plate is 140x or 400x diamond on a 10 mm aluminum block, flat to ±0.04 mm (about 0.0016"). Lee Valley suggests the 400x for general truing and the 140x when you need to take off a lot fast.
• Coarse diamond stone. Lee Valley says a coarse (about 400x) metal-backed diamond plate makes a good flattener and doubles for grinding a primary bevel. There's a catch, though. DMT doesn't recommend its regular sharpening plates for lapping stones, only the ones marked Dia-Flat, and Deneb Puchalski (Fine Woodworking) warns that some diamond stones wear out of flat fast. If you use one, keep it just for lapping.
• Silicon carbide grit on glass. Lee Valley's lapping kit says to true stones with 90x or 180x and finish with 280x, on plate glass, with water as the only lubricant for waterstones. Their guide calls for glass at least 1/4" thick, supported on flat plywood or MDF so it can't flex. A plastic laminate sheet on the glass keeps the grit from dishing the glass itself. (Don't use loose grit on a steel plate for waterstones. Lee Valley says the oxides from a wet ferrous lap will ruin the stone.)
• Wet/dry sandpaper on glass or granite. It's the cheapest way in. Norton says 100 grit, Charlesworth used 180 or 240 on 1/2" float glass, and Caspar used 220 on plate glass 1/4" or thicker. Lee Valley also lists coarse aluminum oxide sheet (over 100 micron) on glass or granite. Sellers' advice for a flat granite tile is to take a straightedge to the store and pick through them until you find a flat one.
• Grooved silicon carbide flattening stone. Norton recommends one. Soak it and the waterstone, then rub them together, and the grooves carry the slurry away.
• Shapton's Diamond Glass Lapping Plate is only for stones of 500 grit (30 micron) and finer. Don't use it on coarse stones, don't put loose grit on it and don't run hot water over it.
• A good straightedge

Steps

1. Wet everything. Soak your soaking stones the way the maker says. Shapton says to give its stones 2 to 3 minutes before lapping and to let other brands soak up all the water they can hold. Set the plate or glass on something solid and flat, and splash it with water.
2. Draw a pencil grid across the whole face of the stone. Fine Woodworking, Lee Valley and Shapton all start this way. The pencil shows you what the stone is doing.
3. Lap with long figure-8 strokes. DMT says to use long, overlapping figure-8s with light to moderate pressure and the whole plate, and to finish lighter so you leave fewer scratches. Shapton's way, forward and back and then both diagonals, works just as well. Turn the stone end for end now and then. Keep it wet, and rinse the slurry out of the plate's grooves as it builds up.
4. Read the grid. The lines go first on the high spots. On a dished stone that's the ends and edges, and the middle hangs onto its lines the longest. When every line is gone, the stone is flat. Lee Valley says not to fuss if it doesn't quite reach the corners, since that's the part of the stone that matters least.
5. Check it with a straightedge. Lay it along the length, the width and both diagonals and hold the stone up to the light. If any light shows under it, go back to the plate.
6. Chamfer the edges. Caspar sands a 45° bevel on every edge of the stone "to prevent flaking." Charlesworth eased the soft edges so they wouldn't crumble. Touch them up after each flattening, since lapping leaves a sharp corner again.
7. Do every stone. The 1000, the 4000 and the 8000 all wear, just at different rates. Rinse and brush each stone before you go to the next grit so coarse grit doesn't ride along and scratch up your finish stone. If you'd rather lap stone against stone, use three and keep rotating them. Lee Valley warns that rubbing just two together can leave one concave and the other convex.
8. Clean up the flattener. DMT says to clean and dry the Dia-Flat after every use, and to scrub any diamond plate now and then with a nylon brush and a mild cleanser. Lee Valley says to wipe the swarf out of an Atoma's channels. Put a straightedge across your plate or glass once in a while too, because a flattener that isn't flat just copies its own error into every stone.

How often? More often than you'd think. Lee Valley says to lap waterstones every 3 to 5 minutes of use. Shapton says to lap every time you sharpen a blade. Charlesworth flattened his 800 after about 100 strokes of back work, and Caspar flattened his three stones before every session, which he said took a minute or so. Plenty of folks flatten at the end of each session so the stones are ready the next time. Oilstones are on a much longer clock: check them with the straightedge now and then and flatten when they show a dish. The rule is little and often. A stone that's barely off comes back in a minute, and a badly dished one costs you a lot of stone.

One for the New England shop: Charlesworth warns not to store waterstones in water if the shop freezes at night, "because the stones will shatter." Come December in an unheated Marblehead shop, my soakers come in the house or get stored dry.

MOAM's shop note: The mistake I see most is flattening the 1000 and calling it done. The finish stone dishes too, just slower, and it's the last stone that touches your edge. The second most common is the fella who flattens only when he can see the hollow. By the time you can see it, you've already rounded a few irons. Draw the grid, lap it out, knock off the edges, and keep your flattener clean and flat. A few minutes, and every stone on the bench is flat.

Sources: DMT Dia-Flat product page and DMT FAQ, Lee Valley's Atoma Diamond Plates page, Lapping Grits instructions, "Getting Started with Japanese Water Stones," "Care and Maintenance of Ceramic and Water Stones" and Sharpening by Hand guide, Shapton Diamond Glass Lapping Plate instructions and FAQ, Norton "A Guide to Waterstones" and "A Guide to Benchstones," David Charlesworth, "A User's Guide to Waterstones" (Fine Woodworking #169), Deneb Puchalski, "Flatten Waterstones with a Coarse Diamond Stone" (Fine Woodworking #224), Hendrik Varju, "Pencil and Paper" (Fine Woodworking), Tom Caspar, "Waterstones" (Popular Woodworking / American Woodworker), and Paul Sellers, "Sharpening on hollow stones."

MOAM Out.

Woodworking Tip of the Day: Keeping Rust Off Your Tools in a Salt-Air Shop

Salt air's good for the soul and murder on a plane iron….. Work a few hundred yards from Marblehead Harbor and you learn it fast. Leave a block plane on the bench Friday, open the garage door on a mild, damp Saturday morning, and there's an orange freckle on the sole and a fingerprint etched into the iron. I'm building a Chamberlain Marblehead gunning dory, and the bronze fastenings don't care about the weather. The plane irons, chisels, saws and cast-iron tops do. So today: why tools rust, what the humidity numbers really are when there's salt in the air, and which coatings actually held up when Fine Woodworking tortured twenty of them.

Why it matters: Rust is iron, oxygen and water getting together. Fine Woodworking's Thomas McKenna lays out the two things that speed it up in a shop like mine: salt, whether it's from sea air or the moisture off your fingertips, and temperature swings that cause condensation. In an unheated garage, when a cold night turns into a warm day, condensation settles on the saw table, the jointer and any hand tool left on the bench. Once it starts, it spreads like a rash. A little surface rust on a chisel back or plane sole is an hour of flattening you didn't need to do. Pitting is worse, and if it reaches the edge, you're grinding the pits out.

The numbers that matter

• Clean steel: CoatingsPro (an AMPP corrosion-industry magazine) puts the critical relative humidity for steel at around 60%. That's the level below which water won't form on a clean metal surface. At 75 to 80% the corrosion rate jumps sharply.
• Salty steel is a different animal. Sea salt pulls water out of the air. Plain salt (sodium chloride) turns to liquid brine at about 76% humidity, but a 2014 study in the Journal of The Electrochemical Society found steel dusted with salt crystals could start rusting at as low as 33%, and from 53% up it rusted nearly as fast as steel sitting under wet brine. Translation for the coast: a shop that feels dry can still rust a tool that has salt on it. Wiping the salt off matters as much as the humidity.
• Dew point: The National Weather Service defines it as the temperature the air has to cool to before it hits 100% humidity. Anything colder than that collects water. Work it out (my arithmetic, using the standard Magnus formula): 60°F shop air at 70% humidity has a dew point of about 50°F. A plane iron that sat at 45°F overnight will sweat the minute that air hits it. Woodworker's Journal's Tim Inman calls it the sweaty iced-tea glass, and points out it's the changing temperature that does the damage, not the cold itself.
• A dry shop: Woodworker's Journal's Chris Marshall runs a dehumidifier year-round in a closed shop, and his humidity hovers around 40 to 50% in the mild months. That's the range I aim for.

What actually works: the Fine Woodworking test

In 2012 Fine Woodworking put 20 rust preventers through ten days of abuse. They coated a cast-iron table saw top, spritzed it with water and left it outside under an overhang. Then they coated A2 tool steel samples and froze and thawed them every day so condensation built up. The saw top showed rust after one night, and the tool steel within 48 hours.

• Top seven: CRC Industrial 3-36, LPS 3, Moovit, Rust Block, WD-40, WD-40 Long-Term Corrosion Inhibitor and 3M Rust Fighter 1.
• Their picks: CRC 3-36 was best overall. It has a petroleum odor, so if you'd rather keep petroleum off your hand tools, they recommended Moovit. LPS 3 and 3M Rust Fighter 1 performed perfectly but left a sticky feel, and LPS 3 was the only product that kept yellow glue from sticking.
• Finishes: None of the products interfered with an oil-based or water-based topcoat, even when they put them right on the wood.
• The surprise: Paste wax is a fine lubricant on plane soles and machine tables, but it didn't offer much rust protection. Camellia and jojoba oil were marginal, and Boeshield T-9 didn't make the top seven.

Now, to be fair to the oils: Lie-Nielsen tells its customers to keep iron tools lightly oiled or waxed and recommends jojoba, and they say it won't interfere with finishes or gluing. And a ship's carpenter writing in Fine Woodworking took camellia oil and several other rust preventers along for nine months on a tall ship, with salt spray and sweaty hands working on his tools, and camellia oil beat them all. Here's how I square it: a thin wipe of natural oil is fine on a tool you pick up every day. A tool that's going to sit in a damp garage for a month gets something that passed the test.

Materials

• A rust preventer that passed the test: CRC Industrial 3-36 for machine tops and idle tools, Moovit for hand tools
• Jojoba or camellia oil for the daily wipe-down, if you like a natural oil
• Paste wax for plane soles and saw tables (to make the wood slide, not to stop rust)
• Clean cotton or microfiber rags
• Rechargeable silica-gel desiccant canisters, or VCI emitters, for the tool chest and drawers
• Evapo-Rust (or a similar water-based soak) for tools that already have rust on them
• A fine abrasive handblock (rubberized abrasive) for light surface rust

Tools

• A digital hygrometer (one in the shop, a cheap one in the tool chest)
• An infrared thermometer to check the iron itself
• A dehumidifier sized for the shop
• A tool chest, till or cabinet with a lid that closes tight

Steps: keep the water off the iron

1. Hang a hygrometer and read it. Know the humidity before you leave for the night. If the shop sits above 50% for days at a time, that's your first job, before any spray can.
2. Close the shop up and dry the air. Shut the doors and windows on muggy days and run the dehumidifier. Empty it regularly, or plumb it to a drain. Fine Woodworking also suggests masonry waterproofing paint on basement walls and sealing garage floors, so moisture can't come up through the concrete.
3. Watch the morning swing. The worst time is a cold night followed by a mild, damp day. Don't throw the garage door open to let the warm air in while the iron's still cold. Shoot the plane sole with the infrared thermometer. If it reads at or below the dew point, keep the tools covered or in the chest until they warm up. Same goes for cranking a heater in a cold shop: the air warms up long before the cast iron does.
4. Wipe every tool before it goes away. Your fingers leave salt and moisture on the steel. A quick wipe with a clean rag takes the prints and the sawdust off. Vic Tesolin points out in Fine Woodworking that dust soaks up moisture and holds it against the steel, which is why old tool chests had a dust seal.
5. Dry it all the way after the waterstones. Sharpening on waterstones (the 10/17 tip) leaves water on the blade, the chipbreaker and the screw. Dry it completely, then oil it. Oil over a wet blade just traps the water.
6. Coat it thin. Hand tools you use every day: a few drops of jojoba or camellia oil, or Moovit, on a rag, wiped on and wiped back off. Cast-iron tops and tools that will sit: a spray that passed the test, like CRC 3-36. Wax on top of that only if you want the wood to slide.
7. Store it closed, with a dry pack. Put a desiccant canister or a VCI emitter in the chest or drawer and keep the lid shut. Fine Woodworking explains that both are made for enclosed spaces: a desiccant fills up and has to be dried out with heat (only some kinds can be), and a VCI gives off a vapor that coats the metal, lasts anywhere from six months to five years depending on the product, and leaks away if the drawer stays open. None of the sprays protect the inside of a power tool, either, so the cases need a dry pack too.
8. Catch it early. A little orange bloom comes off with a fine abrasive handblock; Lie-Nielsen says it uses one in its own shop. Anything heavier goes in an Evapo-Rust bath: the maker says 30 minutes for light rust, up to overnight for heavy. Then rinse with water; the maker calls that step especially important. Let it dry, then coat it.

On the dory: The boat sits where the fog rolls in off the harbor, and the shop sees every swing between a raw November night and a soft, damp morning. So the chisels and the block plane I use every day get a wipe and a few drops of oil when I put them down. The jointer, the bandsaw table and the planes that only come out for the next boat get a coat of something that passed the test. The bronze screws in the planking don't need any of it. And everything that matters lives in a lidded till with a desiccant canister, not out on the bench where the next fog bank can find it.

MOAM's shop note: The most common mistake I see is the guy who waxes his plane soles faithfully and thinks that's rust protection. Wax makes the plane glide; in Fine Woodworking's test it didn't do much to stop rust. The second is the guy who cranks a heater in a freezing garage for a Saturday project. The warm, moist air hits forty-degree cast iron before the iron can catch up, and by Monday the table saw has a rash. Keep the temperature steady if you can, keep the humidity under 50%, and wipe the salt off your tools before you coat them. And if you're near the water, remember: a dry-feeling shop isn't dry enough if there's salt on the steel.

The numbers here come from Fine Woodworking's rust-preventer test, CoatingsPro, the Journal of The Electrochemical Society, the National Weather Service, Woodworker's Journal, and Lie-Nielsen's and Evapo-Rust's own instructions. The dew-point example is my own arithmetic. Read the label on whatever you buy, and test it on a scrap of steel before you trust your good tools to it.

Sources: Fine Woodworking, Thomas McKenna, Got Rust? (July/August 2012); Camellia Oil Outscores Other Rust Preventers; Wax Keeps Rust Off Hand Tools; Vic Tesolin, Keep It Comfortable for You and Your Tools. CoatingsPro (AMPP), How (and Why) to Protect Metallic Surfaces (2012). Schindelholz, Risteen and Kelly, Effect of Relative Humidity on Corrosion of Steel under Sea Salt Aerosol Proxies, Journal of The Electrochemical Society (2014). National Weather Service, Dew Point vs. Humidity. Woodworker's Journal, How Will Cold Air Affect Tool Rusting? Lie-Nielsen, Jojoba Oil and Bench Planes instructions. Evapo-Rust, Four Easy Steps to Rust-Free Tools.

MOAM Out.

How to Sharpen a Plane Iron on Waterstones: Camber vs Straight

This is catching the MOAM's attention today….. a plane that skates, chatters or leaves little ridges across the board almost always has an edge problem, not a plane problem. I've got cedar and white oak to plane for the dory this fall, so today it's the whole routine for a bench-plane iron on waterstones, plus the question that starts an argument in every shop on the North Shore: do you put a curve on the edge, or keep it dead straight? Short answer: it depends on the plane.

Why it matters: A sharp edge is just two polished surfaces meeting, the bevel and the back. Lee Valley and Lie-Nielsen both start there. Skip the back and you get a row of tiny saw teeth that dull in a few strokes. The shape of the edge matters just as much. A smoothing plane with a square iron digs its corners into any board wider than the blade and leaves ridges Chris Gochnour (Fine Woodworking) calls tracks. A rabbet or shoulder plane with a curved iron can't cut a clean, square corner. Smoothing a wide oak plank for the dory, I want the first one curved. Cleaning up a rabbet in the stem, I want the second one straight.

Materials

• Waterstones: a 1,000 grit to raise a burr and an 8,000 to polish, with a 4,000 in between if you like. Christopher Schwarz runs 1,000/4,000/8,000; Lie-Nielsen teaches 1,000 and 8,000–10,000. A 1,000/6,000 combination stone is a fine way to start.
• Wet/dry sandpaper, 100–220 grit, on something flat (granite, a machine bed, ½-in. float glass), or a coarse diamond lapping plate, to flatten the stones
• A thin steel ruler, about 0.020 in. (0.5 mm) thick or less, for the ruler trick
• A pencil, for the flattening check
• Rust protection: light oil (Lie-Nielsen uses jojoba), Boeshield T-9 or paste wax (Lee Valley)
• A scrap board wider than the iron, for test cuts

Tools

• A side-clamp honing guide. A narrow single-roller (Eclipse-style) guide rocks easily, which helps when you're cambering (Gochnour).
• A protractor, or a stop board, to set 25° and 30° the same way every time
• A combination or engineer's square, and a feeler gauge (the same one you gap spark plugs with) to read the camber
• A straightedge for checking the stones
• A strong light, and a loupe if your eyes are like mine

Steps

1. Flatten the stones first. Draw a pencil cross-hatch on the face, then rub the stone on wet/dry paper (100–220 grit) stuck to a flat surface, or on a diamond lapping plate, until the lines are gone. Lie-Nielsen says that's about 15–20 strokes; turn the stone 180° now and then. Check it with a straightedge. Waterstones wear fast, and a dished stone will curve your edge whether you asked for it or not, so flatten again at the end of every session. David Charlesworth keeps his coarse stones in a tray of water (stored dry, they want about a five-minute soak) and just sprays the 4,000 and finer. Glass-backed Shaptons get a spritz, never a soak (Lie-Nielsen's Deneb Puchalski, FWW).
2. Get the back flat where it counts. On a plane iron, the back only has to be flat and smooth near the edge. Lee Valley laps it on an 800 or 1,000 stone, then polishes on a 4,000 or 8,000. Puchalski's goal is a flat back with no heavy milling marks running out to the edge, about 5 to 10 minutes on sandpaper. Don't spend an afternoon polishing the whole thing.
3. Use the ruler trick on the back. This is David Charlesworth's. Lay the thin ruler along one long edge of the 8,000 stone. Lay the iron bevel up across the stone, back resting on the ruler, edge on the stone. That tips the back up less than 1°; Charlesworth figures his 0.5 mm ruler gives about two-thirds of a degree. Stroke on and off the end of the stone, and don't bring the edge more than ½ in. onto it (Lie-Nielsen). Stop when you see an even mirror band about 1/32 in. wide, corner to corner (Puchalski). This is for plane irons only. Never do it to a chisel; a chisel needs a flat back (Lie-Nielsen).
4. Hone a 30° secondary bevel on the 1,000, and feel for the burr. Most bench-plane irons come ground at about 25° (Lee Valley, Lie-Nielsen). Set the guide for 30°. Puchalski: "For the most common primary bevel of 25°, a secondary bevel of 30° works well." Paul Sellers hones his at 30° too. Lie-Nielsen's own basic method goes to 35°, a 10° secondary, and Lee Valley lists 30°–35° for hardwood with pin knots. Four or five passes should raise a burr, a wire edge you can see and feel on the back. The burr test: slide a fingertip across the back and off the edge (never along the edge). You want a faint catch the whole width of the iron. If one corner has no burr, the bevel hasn't reached the edge there yet. Keep going.
5. Smoothing plane? Camber it with finger pressure. Still on the 1,000, press down hard at one corner for a set of strokes, then the other corner, then partway in from each corner, then a few in the center. Schwarz does 10 strokes at each corner, 7 at each in-between spot, and a few in the middle. Lie-Nielsen does 6, 4 and 2. More strokes at the edges than the middle takes more steel off the corners and leaves a gentle arc. Hold the iron against a square: you should see a little light at each corner. How much? Not much. Gochnour says 0.001 to 0.002 in. on a smoother; Lie-Nielsen's routine gives .002 to .005 in.; Schwarz measured .006 in. at the corners of his favorite No. 4 with a feeler gauge.
6. Jack or fore plane? A lot more camber. These are the planes that take the heavy cuts. Schwarz puts an 8-in. radius on his fore plane, and says 8 to 10 in. is typical on a jack. By my math, on a 2-in. iron that's roughly 1/20 to 1/16 in. of sweep back at the corners. That's grinder or coarse-stone work (Schwarz grinds his), then you hone it the same way. It's how you hog a cupped cedar plank down without the corners digging in.
7. Shoulder, rabbet and block planes: straight and square. Lee Valley is blunt about it: joinery planes like rabbet planes are never cambered or given rounded corners, and the edge has to stay square to the sides of the blade. Lie-Nielsen says shoulder planes need a straight edge too. Schwarz lumps block planes in with chisels: sharpened straight across. Even pressure across the guide, and check it with the square. Jointer planes are your call: Lie-Nielsen keeps theirs straight, and some guys add a hair of camber to help square up an edge.
8. Polish on the 4,000 and 8,000, then kill the burr. Same pressure pattern if you're cambering. Puchalski takes four or five passes on the 8,000 and stops when he sees a clean, bright line of even width right at the tip. If it's wider at one corner, your pressure was uneven; a few extra strokes on the narrow side fixes it. Then go back to the ruler trick on the 8,000, about 10 passes on and off, to take the burr off the back (Lie-Nielsen). Put it in the plane, set a light cut and look for see-through shavings.
9. Dry it, oil it, and know when to regrind. Water and steel don't mix, and Marblehead salt air doesn't help. Wipe the iron dry the minute you're done and oil it. Over time the 30° bevel gets wider; when you're taking 20 to 30 passes on the 8,000 to get an edge, Puchalski says it's time to regrind the 25° primary. Lie-Nielsen leaves about 1/64 in. of the old secondary so the square edge stays defined.

MOAM's shop note: The most common mistake I see is too much camber on the smoother. You get a skinny little shaving out of the middle of the mouth and spend all day making passes. Gochnour's rule: if the shaving's narrow, put more strokes in the center; if you still see tracks, put more on the corners. A good smoother shaving is nearly full width and fades to nothing at the edges. Sneak up on it. It's a lot easier to add camber than take it out. That's my own practice, not a number from a book. And pro trick for a New England shop: Charlesworth keeps his coarse stones soaking in a tray, but if your shop freezes at night, don't store them in water. He says they'll shatter. Come November in Marblehead, mine come in out of the cold.

Sources: Lie-Nielsen Toolworks, Sharpening Instructions (rev. 08/2023) and Shoulder Plane instructions; Deneb Puchalski, "Get Sharp—Fast," Fine Woodworking #213; David Charlesworth, "A User's Guide to Waterstones," Fine Woodworking #169, and his "Ruler Trick" video; Thomas Lie-Nielsen, "Sharpening a Plane Iron that has a Pitted Back," Fine Woodworking; Chris Gochnour, "Camber: The Secret to Perfect Planing," Fine Woodworking; Christopher Schwarz, "Camber With a Honing Guide," "Coarse, Medium & Fine," "Yes, You Need a Jointer and a Jack" and "Super-specific Smoothing Plane Specs," Popular Woodworking; Lee Valley/Veritas, Sharpening System instructions, "Getting Started With Your Jack Rabbet Plane" and "Getting Started With Your Veritas Bevel-Up Bench Plane"; Paul Sellers, "One System Fits All" and "Setting your plane after sharpening."

MOAM Out.

Tools for this tip

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• King KDS 1000/6000 combination waterstone: a 1,000 side to raise the burr and shape the camber, a 6,000 side to polish
• DMT Dia-Flat diamond lapping plate (4 x 10 in.) for flattening waterstones: keeps the waterstones dead flat so they don't put a curve in your edge you didn't ask for
• Starrett 12-inch combination square (11H-12-4R): holding the iron to the blade to check the camber, or that a rabbet iron is straight and square
• iGaging 6-inch digital caliper: checking your ruler-trick ruler is about 0.020 in. thick
• The Complete Guide to Sharpening by Leonard Lee (book): the standard reference on sharpening

Use whatever you already have in the shop; these are just the ones that fit this job.

How to Hone a Chisel Micro-Bevel for a Tougher Edge

Not for nuthin'…. But….. if you're honing the whole bevel every time your chisel goes dull, you're working way too hard. A micro-bevel is a skinny second bevel, a few degrees steeper, right at the cutting edge. It takes a couple of minutes, it gives you a tougher edge, and it means touch-ups take a handful of strokes instead of half an afternoon on the stones.

Why it matters: Only the very edge of a chisel does any cutting. Bob Smalser, a boatbuilder who wrote "All About Chisels" for Fine Woodworking, puts it this way: since only a few thousandths of an inch actually cuts, why hone the entire bevel every time? Building the Chamberlain Marblehead gunning dory, a chisel spends its day paring hardwood and cleaning up around glue-ups, and a thin edge rolls or chips fast in that work. A slightly steeper angle right at the tip holds up better, and you get there with less steel coming off. Same story on the GC side: hinge mortises, door hardware and trim scribes all go quicker with a chisel you can get sharp in two minutes.

Materials

• Sharpening stones, coarse to fine. Lie-Nielsen's method uses a 1,000-grit stone to hone, a medium 3,000 for chisel backs, and an 8,000–10,000 finishing stone. Oil stones work too: Lie-Nielsen lists soft, hard and black hard Arkansas as the coarse, medium and fine equivalents.
• Wet/dry sandpaper (120–220 grit) on a flat surface, or a lapping plate, to flatten the stones
• A scrap of plywood and a stop block to build an angle-setting jig (Lie-Nielsen publishes plans)
• Light oil to wipe the chisel down after (Lie-Nielsen recommends jojoba oil)
• A scrap of softwood to test the edge

Tools

• A side-clamp or roller honing guide (Lie-Nielsen, Veritas Mk.II, or an Eclipse-style guide)
• A protractor or angle gauge to set the guide the first time
• A bench grinder or coarse abrasive, only if you're putting a fresh primary bevel on a beat-up edge
• A strong light to read the bevels, and a magnifier if your eyes are like mine

Steps

1. Flatten and polish the back, once. The back of a chisel is a reference surface. It has to be flat for the last inch or so behind the edge and polished as fine as the bevel. Lie-Nielsen works it on the honing stone, then the 3,000, then the finishing stone, sliding the blade on and off the end of the stone so you don't round over the tip. After that first job, the back only ever sees the finishing stone. And unlike a plane iron, never use the "ruler trick" back bevel on a chisel. Lie-Nielsen says it flat out: chisel work needs a flat back.
2. Set the primary bevel at 25°. That's a solid all-around bench-chisel grind. Lie-Nielsen grinds its fishtail chisels at 25°, and "grind at 25°, hone at 30°" is the old rule you'll hear in every shop. (Lie-Nielsen's bevel-edge chisels come ground at 30°, so if you own those, the same 5° bump puts you at 35°.) Hone or grind until the bevel runs all the way to the edge and a burr forms across the whole width. Veritas says the primary bevel should extend at least ⅛″ back from the edge.
3. Raise the angle about 5° for the micro-bevel. Lie-Nielsen recommends an extra 5° on its chisels, and Fine Woodworking's Smalser says raise the handle 2° to 5°. For a stop-block jig with a Lie-Nielsen guide, the company's chart says to shorten the blade's projection from about 1½″ (25°) to about 1⁵⁄₃₂″ (30°). Those distances are approximate and only for Lie-Nielsen's guide. Set other guides with a protractor and make your own stop block. The Veritas Mk.II has a built-in cam: knob at 12 o'clock for the primary, 6 o'clock adds a 1° to 2° micro-bevel. That's less than 5°, but it still does the job.
4. Hone the micro-bevel. On the 1,000 stone, take a few strokes until you can feel a fine burr (wire edge) all the way across the back. Then go to the finishing stone for a few more. Done right, you'll see a thin, bright strip at the very edge. Keep it skinny. It only needs to be a hair wide, roughly ¹⁄₆₄″ to ¹⁄₃₂″, and the narrower it is, the faster it polishes.
5. Kill the burr on the back. Lay the back dead flat on the finishing stone and take a few passes, on and off the end of the stone. Don't lift the handle even a hair. Fine Woodworking warns that lifting the blade while it's moving puts a micro-bevel on the back, and that wrecks the reference surface you just worked for.
6. Test it. Pare across the end grain of a piece of pine. A sharp edge leaves a clean, shiny cut. A dull one crushes and tears the fibers. Then wipe the steel with oil, because a New England shop in October is a rust factory.
7. Touch up fast, regrind once in a while. When the edge dulls, Lie-Nielsen says a quick polish on the finishing stone may be all it takes. To raise a new wire edge, go back to the honing stone first. Every honing makes the micro-bevel a little wider, so Smalser goes back and restores the main bevel every third or fourth honing. Lie-Nielsen says to leave about ¹⁄₆₄″ of the old secondary bevel when you regrind so the square edge stays defined. Then start over at step 3.

Picking your angles: Fine Woodworking's Smalser gives 15°–20° for paring chisels that never see a mallet, 20°–30° for general bench chisels, and 30°–40° for mortise chisels that take a pounding. Lie-Nielsen adds that on very hard woods like oak, hard maple or exotics, you should take lighter cuts and use a higher secondary bevel. My numbers below are a starting point. If an edge chips, go steeper. If it pushes hard and won't take a fine shaving, go lower.

MOAM's shop note: Don't take your good paring chisel to hard epoxy. WEST SYSTEM says to remove or shape squeeze-out as soon as the joint is clamped, while the epoxy is still wet, using a mixing stick with one end sanded to a chisel edge. Once it kicks, it goes through a rubbery "green" stage where you can dent it with a thumbnail, then cures hard enough to sand. So clean it up wet with a stick, and you won't be chopping it off cured with a chisel. When you do have to pare cured squeeze-out, my own trick is to keep a beater chisel with a steeper micro-bevel, around 35°, just for that job. That's my practice, not a number from a book. The most common mistake I see is a micro-bevel that's gotten fat because nobody ever regrinds. When honing starts taking forever, that's your sign.

Sources: Lie-Nielsen Toolworks, Sharpening Instructions (rev. 08/2023), Bevel Edge Chisels and Fishtail Chisels instructions; Bob Smalser, "All About Chisels," Fine Woodworking Tools & Shops 2006; Fine Woodworking, "How to Sharpen a Chisel Freehand"; Lee Valley/Veritas, Mk.II Honing Guide instructions and "Setting Up the MK II Honing Guide"; WEST SYSTEM User Manual and "Epoxy Chemistry Basics."

MOAM Out.

Tools for this tip

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• DMT D8EE Dia-Sharp extra-extra-fine diamond plate: fine diamond plate for the micro-bevel
• Narex Premium bevel-edge chisel set (4 pc): good chisels worth sharpening
• The Complete Guide to Sharpening by Leonard Lee (book): the standard reference on sharpening

Use whatever you already have in the shop; these are just the ones that fit this job.

How to Sharpen a Card Scraper and Roll a Burr That Makes Shavings

This is catching the MOAM's attention today….. a ten-dollar rectangle of steel that will out-smooth your random-orbit sander on curly mahogany. That is, if you sharpen it right. Most folks crank a big fat hook on it, get a cloud of dust, decide scrapers are overrated and hang it back on the wall. Here's how to tune a card scraper so it peels shavings off like a good smoothing plane.

Why it matters: A scraper takes tearout out of wild grain that no plane will touch, and it leaves no sanding scratches to show up under varnish later. On a boat that's half the brightwork. WoodenBoat's varnishing guide suggests a cabinet scraper for smoothing big bare-wood surfaces like transoms and cabinsides before the sealer coat, and says to scrape a sag out of a cured buildup coat before you sand. Mahogany and white oak trim with interlocked or reversing grain are exactly where a plane tears out and a scraper doesn't. And it's the best tool going for cured epoxy squeeze-out, drips and runs on a hull. Gougeon's people point out that scraping epoxy, especially green epoxy, keeps it from going airborne the way sanding dust does. The catch is that a scraper is only as good as its hook, and the hook is only as good as the square, polished edge under it.

Materials

• A card scraper. Common stock runs from .016″ to .042″ thick (0.4 to 1 mm). Lee Valley sells .016″ and .024″ for fine finishing and .032″ and .042″ for heavier work and paint. Lie-Nielsen's pair is .020″ (supple, good for short, complex surfaces) and .032″ (stiffer, takes a heavier cut on bigger surfaces). If you only own one, make it something in the .020″ to .032″ range.
• A few drops of light oil for burnishing. Lee Valley's instructions note that a fingertip rubbed behind your ear carries just about the right amount.
• A permanent marker
• A hardwood scrap 1¾″ × 1¾″ × 8″ for a filing block
• Duct tape or fine-line painter's tape, for the epoxy-drip trick below

Tools

• A 10″ single-cut mill file. Bob Van Dyke uses a mill bastard. Christopher Schwarz prefers a finer second-cut or smooth file because a coarse one leaves deep scratches in soft scraper steel.
• Sharpening stones or plates: a 1000 waterstone plus a 4000 to 8000 polishing stone, diamond plates, or wet-or-dry paper on glass from 180 or 320 up to 600
• A burnisher: a hardened, polished steel or carbide rod. Ron Hock (quoted by Schwarz) puts burnishers around Rc 58 to 60. Plain spring-steel scrapers run about Rc 38 to 42 and the premium ones Rc 48 to 53 (Lie-Nielsen's are 49 to 51), so the burnisher always wins. Paul Sellers gets by fine with the back of a chisel or a nail set. If freehand angles give you fits, the Veritas Variable Burnisher dials in anything from 0° to 15°.
• A bench vise
• A flat refrigerator magnet. Matthew Teague sticks one on the scraper as a thumb heat shield, and on a long session your thumbs will thank you.

Steps

1. Make a filing block. This one's Brian Boggs's idea, via Fine Woodworking's Michael Pekovich. Bandsaw a 7″ kerf down the length of that 1¾″ × 8″ hardwood block. Slip the scraper in so its edge stands barely proud of the wood (no more than 1/64″) and clamp the block in the vise. Now the file rides the block and can't go out of square.
2. Joint the edge square. Color the edge with marker. Lay the single-cut mill file flat across the block and take long, full-length push strokes. Files cut on the push. On a used scraper the file will skate over the work-hardened steel at first. Keep going until it cuts steadily and the ink is gone. Do both long edges.
3. Hone the faces and the edge. Faces first. You only need the first ½″ or so next to the edge, not the whole card. Go from a 1000 stone to a 4000 to 8000, or from 180 or 320 paper up to 600. Then hone the edge with the scraper held square against a wood block standing on the stone. Move the scraper, not the block, and wander over the whole stone so you don't wear a groove in it. Alternate face and edge until the filing burr is gone and the corner is crisp and polished. Don't mistake that filing burr for a hook. It'll cut, but it leaves a rough surface and dulls fast.
4. Draw the faces. Lay the scraper flat near the edge of the bench and put a drop of oil on it. Hold the burnisher flat on the face, or tipped a degree or two toward the edge, and take firm strokes along the full length, with the burnisher skewed a bit. Schwarz uses five or six strokes. Paul Sellers bears down hard and takes 20 or 30. Do both faces at each edge. This work-hardens the steel and draws a hair of it out past the edge, so the hook turns easily.
5. Turn the hook. Clamp the scraper upright. Lee Valley leaves about 1½″ above the jaws, and Sellers sets it about ⅛″ above his holder block. Lay the burnisher across the edge, square to the faces, then tip it a few degrees. About 5° is a good place to start, and the sources are all over the map here. Tage Frid held his at 85° to the face, which is 5°. Van Dyke goes 3° to 4°, Pekovich just 1° to 2°, and Teague says anything from 1° to 15° works. Lee Valley says most scraping falls in the 3° to 10° range. Schwarz tried 5°, 7°, 10° and 15° hooks side by side and got excellent shavings from all of them. Take two or three light strokes. Tage Frid put it at about 4 oz of pressure, and Schwarz calls it the pressure you'd use to spread butter on bread. Then tip the burnisher the other way for the second corner. A good hook feels like a tiny lip your fingernail can almost catch.
6. Hold it, flex it, lean it. Fingers on the short ends, thumbs together in the middle of the back about ½″ above the edge, and push just enough to put a slight bow in it. More bow gives a narrower, deeper cut. Lean the top forward in the direction of the push. Schwarz works between about 60° and 65° to the surface. Teague starts beginners around 60° and adjusts until the hook bites. Tage Frid started vertical and tipped it until it bit, at about 70°. The lower your hook angle, the more upright you can stand the scraper. Push to chase tearout. Pull, with your fingertips behind the edge, to flatten the slight dish a push stroke leaves. Feather your work out around a bad spot so you don't scoop a divot that shows under varnish.
7. Read the chips. Fluffy, curly shavings mean you're sharp. Dust means you're not. Change your angle first, then check that the hook is still there. Van Dyke figures five to ten minutes of steady scraping before the shavings fall off. Don't push on into dust, because scraping dull rounds over the jointed edge and leaves you nothing to turn a new hook from.
8. Re-turn it before you refile. When the shavings quit, re-draw the faces and re-turn the hook. No filing. Lie-Nielsen says you can usually do that a few times. Teague gets four to six burnishings, and Van Dyke and Tage Frid five or six, before the steel gets work-hardened and brittle. Pekovich says the hook actually lasts longer the second and third time. When it won't take a clean hook anymore, back to the file and start over.

MOAM's shop note: The common mistake is too much pressure and too much angle. You get a big, fragile hook that's hard to control, and Pekovich warns that heavy burnishing can crimp the steel so badly you have to file it off and start over. Go light and stop as soon as you can feel the hook. Pro trick for the boat shop, from Gougeon's Tom Pawlak at Epoxyworks: for a cured epoxy drip about ½″ wide, tape off the scraper's edge everywhere but the center inch. Lean it forward and push along the drip with the blade square to it. Each pass peels a ribbon, and the tape stops the cut right at the fair surface, leaving the drip only a few thousandths proud. Knock that down with a small hard block and wet-or-dry paper. No sanding swirls on your topsides and no epoxy dust in the air. Here in Marblehead we call that a fair trade.

Sources: Bob Van Dyke, "Learn a fast, reliable way to sharpen a card scraper," Matthew Teague, "Mastering the card scraper," and Michael Pekovich, "The right way to sharpen your scraper" (Fine Woodworking); Tage Frid, "The Scraper" (Fine Woodworking #6); Christopher Schwarz, "A Better Way to Sharpen Scrapers" (Popular Woodworking); Lie-Nielsen Toolworks hand scraper instructions; Lee Valley/Veritas Variable Burnisher instructions and scraper specs; Paul Sellers; Tom Pawlak, "Scrapers: Versatile Tools for Working with Epoxy" (Epoxyworks/WEST SYSTEM); Matthew P. Murphy, "Varnishing Basics" (WoodenBoat); Chesapeake Light Craft, "Cabinet Scrapers for Boatbuilding."

MOAM Out.

Tools for this tip

As an Amazon Associate I earn from qualifying purchases.

• Bahco 474 card/cabinet scraper (2-pack): the scraper itself
• Nicholson 8-inch mill bastard file: jointing the edge square
• DMT D8EE Dia-Sharp extra-extra-fine diamond plate: honing the edge before burnishing
• Crown 377C cabinet scraper burnisher: rolling the hook

Use whatever you already have in the shop; these are just the ones that fit this job.