Hand Plane Rehab

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This article is from Issue 39 of Woodcraft Magazine.

A plain and simple prescription plan for old and new planes

It’s common knowledge that an old hand plane usually needs some TLC to get it into top working form. But you may not realize the same is true for most new planes. Regardless of a tool’s age, the trick to tuning it up is determining whether it needs a bit of preening or a complete overhaul. Tearing a plane apart isn’t terribly difficult, but unless the tool is a basket case, a full renovation is the woodworking equivalent of performing a heart transplant to treat a hangnail. A soup-to-nuts treatment can be expensive and time consuming. There’s also a risk that overwork might diminish a tool’s value or even damage it. Why take the chance if you don’t need to?

As a card-carrying member of the “If it ain’t broke, don’t fix it” society, I’ve combined techniques gleaned from other stories, conversations with tool collectors, and my own experience to develop a three-level tuning strategy. The advantage to my approach is that it can be used not only to revive old planes, but also to fine-tune newer ones that aren’t living up to their full potential. With the following instructions and a little practice, you’ll be able to quickly diagnose and treat those tools that require only a little first-aid, or decide whether or not a plane warrants heroic measures.

Pick a plane, any plane (almost)

To figure out how planes work, it’s best to start with one that's been around the block a few times. In addition to Stanley Baileys and Bedrocks, you may find decent planes bearing names including Sergeant, Miller’s Fall, Victor, or Winchester. (Consult woodworking hand tool forums online for information and opinions on plane pedigrees.)

If you’re lucky, you can snag a respectable tool for under $20. However, because bargain planes often suffer from missing parts or defects, consider investing a few more bucks. When you come across an attractively-priced candidate, remember to factor in the cost of a replacement blade. For example, a $60 No. 3 might sound like a steal, but if the plane needs a new $40-100 blade, it’s not such a great deal compared to a brand new WoodRiver No. 3 at $120.

Start with a careful cleaning

As shown in Figure 1, there aren’t many parts to a bench plane, but for smooth adjustments and clean cuts, everything should be in good working order.

Start by cleaning the tool. This will give you an opportunity to learn how the parts fit together, and to look for any fatal flaws such as cracked castings or missing parts, before you invest too much time or money.

Before knocking off any rust, remove the knob and tote. Light rust can usually be erased with Sandflex blocks, or mineral spirits and steel wool. For heavy rust, I’ll use a chemical remover like Top Coat, or place the parts in a plastic tray and treat them using a process known as “electrolysis.” To prevent rust from blooming the instant you put the tool on the shelf, apply a light coat of oil or wax to all metal surfaces.

Date to Remember 

Like many old-tool users, I’ve found that pre-war planes (1941 or earlier) require less work than post-war planes. The Web is crawling with plane-dating flow charts, but to quickly ballpark a plane’s age, check the frog and tote. Most pre-war planes, like this No. 3, have flat-faced frogs and varnished totes; post-war versions, like this No. 41⁄2, have raised-faced frogs and painted totes.

Initial diagnosis

After cleaning a plane, it’s wise to establish a performance baseline before doing further work. To do an initial test, sharpen the blade (See “Sharpening made simple,” page 31), and check or replace the chipbreaker. Now make a few test shavings. 

There’s a slim chance that the plane was well cared for. If it produces silky shavings of consistent thickness, you can consider yourself lucky that your job is done. In most cases, the repair work is just beginning.

As shown at right above, rehab work falls into three levels. The approach you choose depends not just on the cost and condition of the tool, but also on how you plan to put it to work. For example, jack, fore, and jointers—planes used primarily for rough work—rarely require more than a mid-level tune-up. Smoothing planes deserve more attention in order to produce the wispy shavings necessary for refined work.

Dress the edge to close up a blade/breaker gap. Site on the screw hole to set the grinding angle.

Level 1

Check the chipbreaker

Positioned about 1⁄16" behind the cutting edge of the blade, the chipbreaker forces the approaching shaving backwards, “breaking it up” before it can start tearing away from the surface. It also helps direct shavings through the plane’s throat. To work like it should, the edge of the breaker must contact the blade perfectly, or else shavings can jam in the gap and choke your plane. Most secondhand planes suffer from this ailment.

To close the gap, hone the underside of the leading edge on fine-grit sandpaper until it’s straight and flat. To establish a consistent angle, move the chipbreaker as shown in Photo A, keeping the screw hole aligned with the edge of your honing platform.

While you’re at it, polish the top of the chipbreaker to minimize friction against the approaching shavings.

Flatten the sole

For a plane to work properly, the sole must be flat and smooth. Its flatness ensures that it will create flat surfaces. Smoothness contributes to an easy gliding operation and prevents any deep scratches from marring a workpiece.

Flattening a sole isn’t difficult, but it’s typically the most time-consuming step in the plane-tuning process. You’ll need a few packs of sandpaper in successively finer grits ranging from 80 to 400. You’ll also need a dead-flat reference surface on which to work. Here, I used a piece of 3⁄4"-thick float glass on top of a piece of 1"-thick MDF, but you can work on a tablesaw or jointer table instead.

Because cast iron is slightly flexible, you want to inspect and lap the body under normal working tension. Install the blade, chip breaker and lever cap, but retract the blade into the body. Next, use a permanent marker to draw reference lines across the sole. Rub the plane back and forth across a strip of 220-grit paper a few times then check your progress. This is your starting point.

Put on your favorite CD, and start flattening. To keep the sanding consistent, I prefer running the plane over the sandpaper in one direction, then the other, as shown in Photos B and C, below. In a perfect world, the entire sole should be dead flat. Realistically, a few minor hollows aren’t likely to compromise accuracy in use. (Compare the “Before” and “After,” below). It’s sufficient to flatten most of the sole, focusing primarily on the toe and heel areas and the section in front of the mouth. The latter is particularly important, because its job is to hold down the wood fibers to prevent tear-out as the blade tries to lift them.

Flattening will produce knife-sharp corners. To protect your work (and your fingers) lightly ease the edges with a fine mill file. Once you’ve done the preliminary flattening, it’s time to smooth the sole. I dry-sand it using 400-grit non-loading stearated paper, but you could use 400-grit wet/dry paper, lubricating it with mineral spirits.

With the blade retracted, scrub the sole, applying the same pressure as you would use to plane a board.
Rotating the plane ensures that the sanding is even across the sole.

Grit Guidance

If a sole doesn’t yield to 220 grit after some concerted work, downshift to coarser paper. When the sole exhibits a consistent scratch pattern, move up to the next finest grit and continue the process through subsequently finer grits, finishing up at 400 grit.

Use an accurate square to gauge how much material to remove to correct imperfections in a mouth, or to widen it to accept a replacement blade.
For better visibility when filing, apply tape adjacent to your gauge line. Tape the underside of the file to protect the back edge of the mouth.

Level 2

File the mouth

If the front edge of the mouth is chipped, out of square to the plane sides, or too narrow for a blade, you’ll need to correct things with a file. While filing the mouth isn’t particularly difficult, it’s important that it remains straight and perpendicular to the sides of the plane. Otherwise, it won’t reliably hold wood fibers down directly in front of the blade, leading to possible tear-out.

To work on the mouth, clamp the lower section of the body in a vise without squeezing against the tall sides. Using an accurate square and a scratch awl, gauge the amount to file away from the front edge of the mouth, as shown in Photo D. Aim to remove as little material as possible to correct a chipped or out-of-square edge. Then use a bastard file to work to your line (Photo E), filing the throat back a few degrees to improve chip clearance.

Opening the mouth wider is necessary for many replacement blades. (See, “Buy A Better Blade?” below.) In this case, you’ll need to file away about 1⁄16".

Buy A Better Blade?

There’s no shame in sticking with a vintage blade (especially those bearing the Stanley Sweetheart logo), but if the blade has a pitted back, or is too short from repeated sharpenings, you’ll need to buy a replacement.

The blade you choose will not only affect the plane’s performance, but will also determine how much work you’ll need to do to make it fit. As shown at right, older planes employed relatively thin (.080") blades. Nowadays, thick is in. Stanley replacement blades, available from several different manufacturers, will fit most planes with little to no adjustment. The Pinnacle/IBC blade will require you to open up the mouth.

Is it worth it? It depends. Many woodworkers find that a thinner blade will work fine provided that the rest of the plane is properly tuned. Thicker .095"-thick blades are a price-conscious solution to improving a plane’s performance. For smoothers, such as the No. 41⁄2 shown in this story, I found that the thicker blade resisted chatter better than the thinner ones.

I suggest working with what you’ve got before making an upgrade. Much like stepping up to titanium golf clubs or parabolic skis, you need to experience the “before” of a vintage high-carbon blade in order to appreciate the benefits of an upgrade.

Level 3

Fine-tune the frog

In order to secure the blade to the body, the frog must be in solid contact with both parts. Some tune-up articles lead off with frog tune-up, but I recommend doing this step last for two reasons. First, too much tuning can ruin a good plane. Second, most frogs don’t need any work. If the contact points are painted, dinged up, or clearly mis-mated, read on; if not, skip this section until you’ve made some shavings.

First, clean up the frog’s wider rear contact points. To do this, affix a strip of 220-grit sandpaper to a flat reference surface and rub the frog from side to side (Photo F). Don’t oversand; as long as the surface is flat and clean, minor mill marks are perfectly acceptable.

Next, clean the lower contact points. This can be done freehand, but I use a simple jig that provides a wider bearing surface for a sanding block (Photo G). To gauge your progress, color the contact points with a permanent marker, and stop when most of the ink is gone.

To dress the contact points on the body, attach 220-grit self-adhesive sandpaper to the sanded surfaces on the frog as shown in Photo H. Set the the frog in place and rub it about, as shown in Photo I. Again, easy does it.

Finally, check the flatness of the frog face using a permanent marker, sandpaper, and a reference surface. A minor hollow isn’t a concern, but a humped area near the bottom can cause the plane to chatter in use. Use 220-grit paper to remove any high spots.

Lightly dress the rear contact points by running the frog against 220-grit sandpaper.

Clean up the bottom contact points with a sanding block. The jig provides a wider bearing surface.

Apply sandpaper to the frog’s front and rear contact points.

Rub the frog in all directions to clean and dress the contact points on the body.

Setting the frog

Reattach the frog, tightening the screws just enough to hold an adjustment without it slipping around. Next, install the blade and chipbreaker assembly and lever cap. Adjust the frog to create an even 1⁄16" gap between the blade and the front of the mouth. (You’ll want to close it up more when planing tear-out-prone woods.) Finally, remove the lever cap and blade assembly, tighten the frog-holding screws, then reassemble.

Ready, Set, Shave

Setting up a plane is a little confusing at first, but with practice it will become second nature. Secure the chipbreaker to the flat (back) face of the blade and then carefully install the assembly onto the frog. Snap the lever cap in place, and then retract the blade into the body.

Secure a test board on your bench, and run the plane across the wood. Slowly rotate the depth adjustment knob until the blade begins to bite into the wood. Adjust the lateral adjustment lever to center the shaving on the blade. Your plane is now ready to shave.

If you retract the blade during the adjustment process, spin the knob until it reseats against the yoke to remove any backlash.

When polishing the back face, a taped-on block offers grip and evens out downward pressure.

Sharpening made simple

A sharp blade is crucial to both plane assessment and proper post-op use. Following is a stone-simple procedure that costs less than $45 for supplies. (Adding an 8000-grit for the two-stone simple treatment will set you back another $60.)

First, hone the back of the blade to flatten and polish it. I prefer to do this on sandpaper spray-adhered to a granite stone (Photo J). As when flattening a plane sole, start with 220-grit paper, moving to a coarser grit if a concerted effort doesn’t start removing mill marks, rust and other defects. Progress to finer grits of sandpaper as soon as you have established a consistent scratch pattern. Work through 320-, 400-, and 600-grit paper, wipe off any loose grit, and then finish honing the back with your waterstone(s) until you get a near-mirror finish.

Paired with an inexpensive honing guide, this two-stone station makes the sharpening process quick and consistent.

Now work the bevel. Set a honing guide to establish a 25° bevel. You can adjust the blade in the guide so that the bevel rests completely on the stone, but to keep things consistent, I screwed a stop to the edge of the sharpening station (see Photo K). Wheel the guide back and forth across your 1000-grit stone until you feel a wire edge on the back edge of the blade. 

To speed up the sharpening process, I prefer to hone only a portion of the primary bevel, creating a slight “secondary bevel.” To do this, I use a 1⁄8"-thick spacer and slide the blade back in the honing guide. Roll the blade over the 6000-grit stone a few times and, if you have one, the 8000. Now turn the blade over and check your progress. The resulting edge will appear as a thin band, as shown in the blade photo, above.

Draw the back of the blade over your finest waterstone, then the front, until the wire edge falls off.

As a final step, draw the back of the blade on the stone, as shown in Photo L, and then flip the blade and again hone the bevelled edge until the wire edge falls off. Now remove the blade from the jig, and wipe it down with oil to prevent rust.

After several honings, the 27.5° bevel will begin to get as wide as the primary 25° bevel. When that happens, you have a choice. You can regrind the primary angle, or to save time, you can use the 27.5° as your primary angle and use the second stop to hone a new 30° secondary bevel. Because of the way the blade is oriented in the plane, a few extra degrees do not affect the plane’s performance.


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