Rehabilitating Old Chisels
by Bob Smalser
This article first appeared as a thread on theWoodenBoat Forum. It was compiled and reproduced here for easier public consumption. All Text and Images are the property of Bob Smalser.
I was in the market for a large framing chisel on Ebay and wound up with a package deal for 30 bucks.an old Stanley 5C Type 16.the Lakeside 2" Framing Chisel I wanted.a beater chisel with a mangled socket.and an old cooper's shaping chisel:
This article will deal with the two framing chisels.the cooper's chisel was usable as is with some cleaning and sharpening, and the plane I'll cover in another article, although I'll rehabilitate them together. These will be put back to work as users, like all my tools.restoration of collector items is another subject.
For this article, I'll purposely use only the minimum tools and techniques necessary for a first-class job.and all the work done in a crude, temporary 12' by 12' shop. My intent is to provide a model for newcomers to the craft who will benefit greatly from acquiring older but high-quality tools in need of a hug for very little money.and putting them back into service without a lot of machines and fancy gizmos you don't have yet. Moreover, with enough practice rehabbing old tools, making new ones like in other articles I've written, and doing traditional joinery for your workbenches and other shop necessities.by the time you create for yourself a nice workshop, you may find you no longer feel a need for all the trendy doodads being shilled at you weekly. I'm not saying that all those expensive tools and jigs aren't useful or don't have a place, I'm merely trying to provide you something to help set those priorities.
I use a large, 8" gunsmith's pedestal buffer-grinder for most of my grinding and polishing chores, but a smaller 6" bench grinder will also work fine. I'da used a smaller bench grinder for the pics.but I don't own one.
I use a soft steel wire wheel to clean all metal parts thoroughly.the cooper's tool has been cleaned in the shot above.
Then I treat them with a phosphoric acid solution (above) available at home improvement chains to kill any remaining rust. This is the functional equivalent of using an electrolysis solution for those not so inclined. The phosphoric acid is allowed to sit over night to work. The next day, the black oxide rust residue is removed with the wire wheel in preparation for buffing and finish later.we need to do some rough grinding and make and mount the handles, first.
The treasure of the lot is the one in the worst shape; of course.a Robert Duke Diamond Brand firmer-style chisel of lovely, glass-like cast steel. It had lost its handle ages ago and probably served to cut the heads off nails with a large, ball peen hammer in its old age. The socket tang was badly mangled with the remnants of the old handle remaining in the void. The tang was returned to its original form by drilling and filing the socket mortise, and grinding off the metal extruded on the outside. Fortunately, there was enough socket mortise remaining to use or I would have required the services of a neighbor I trade work with.and his TIG welder.to build it up. Using heat-sink paste and wet rags, I might have been able to build up the socket with my torch welding setup without ruining the blade's temper, but it would have been riskier, and I'm not near the welder my professional neighbor is.
As the blade was badly chipped and had lost its bevel, grinding was required. While I have a jig for this, I rarely use it any more and freehand the 25-degree bevel using lots of water.turn that blade edge 600-degree blue and it has lost its temper and all the blue must be ground away.and I use a square and protractor to check my progress. You should use a 6" bench grinder with all the guards and a proper tool rest for this..and wear glasses, of course.
As the other blades are in better shape, and I don't prefer to leave the bevels of heavy chisels and slicks with a hollow grind (although not important.merely personal preference), I finish the grinding stage for my 25-degree bevels on the belt sander chucked in the Workmate. I use 60, 80, 100 and 150 grits lubed with WD-40 and lots of water, checking my bevel angle and edge with protractor and square as I go.
Final honing of 25-degree bevel and 30-degree secondary bevel will come later.
Next I rough out my handle stock. There are better choices for handles that occasionally will be struck, but I have some Honduras Mahogany left over from a boat project and will use that. I rip a 2" turning square of it on the table saw, 8-side it on the same saw, and cut two handles to length.the finished length of each handle to equal the length of blade and tang. I then 16-side them using a couple rehabbed old smoothing planes set for coarse and fine cuts. And except for the hanging hole in the 5C above, the Stanley 3C and 4C in the picture were in worse shape when I acquired them to replace the family's old beech smoothers.the ones I used exclusively for 20 years.I was getting tired of renewing mouths and soles on those.
Then I move to the shaving horse and shape them into cylinders using two spokeshaves set for coarse and fine cuts just like the planes.
Next I'll fit the ferrules on the striking ends of the handles. These are simple sections of 1 ¼" brass pipe salvaged from an old plumbing fixture with hacksaw and buffer-grinder. The centers are laid out, an interior line penciled.
.and the actual ferrule and masking tape used to lay out the cut line for the saw. The dovetail saw is marked with a piece of masking tape functioning as a depth gage, the ferrule shoulder circumference cut to depth, the waste pared away with gouge and chisel, and final fitting for a tight, drive fit done with the patternmaker's rasp. I don't want the ferrule to slide on easily without crushing wood, so I fit it so the ferrule has to be heated a bit to fit.coat the wood tenon with a bit of thickened and dyed epoxy.with care in making an epoxy bed at the shoulder so the ferrule won't act as a riving knife and split the wood when struck.and drive on the hot ferrule.
I'll also epoxy the chisel sockets later. Why glue them on? Well, thickened epoxy provides a microscopically perfect fit and rock-hard surface, so when the handle is struck thousands of times during its life there will be minimum wood crushing and the resulting camming action that will eventually wear it out. And when it has to be replaced eventually, it is a simple matter to heat the metal to the 110 degrees required to break the epoxy bond. This isn't traditional construction, but it is unlikely that I or even my sons will have to replace these handles again in our lifetimes.
I do similar to fit the chisel sockets. But as these are tapered, I find it convenient to use the sanding disk on the buffer-grinder, driving on the socket occasionally to mark high spots on the wood. You can see the high spots that have to be reduced where the fibers have been crushed shiny by the drive fit.but you can also use sooty smoke from an alcohol lamp burning mineral spirits, Prussian Blue machinist layout paste, or Mama's lipstick to perform the same function.
Next I want to lay out the shape of these 2" diameter handles. As my favorite handle shape is one I used for turning cherry handles for Grandpa's old drawknife a couple decades ago, I simply eyeball the proportions for the new handles and lay out my guidelines using masking tape that I will simply slice through during shaping.
The sockets are also driven on with thickened epoxy.
After the epoxy cures, I rough out the shape using coarse spokeshave.
.and coarse rasp. Note the selection of finer rasps and various old machinist files on the bench. The better you become at cross and draw filing and the better your selection of file grades, the less sanding you will have to do. And smile knowingly but ignore pundits who claim only cutting blades should ever touch fine wood. Like those folks who claim planes should always be left on their sides instead of their soles when laid down, these practices are hardly universal among master craftsmen.or even important, for that matter. I've seen it done both ways in a dozen or more shops I've worked in and observed.and I've seen it done both ways well. In fact, all the master stock makers I know always reach for the rasps when working thousand-dollar blanks of figured walnut for wealthy and discriminating clients.no risk of tear out in swirled grain that is impossible to read, let alone slice cleanly.
If you are confident using successive grades of abrasive paper, you should be just as confident with rasps. The work looks ugly, but the ugliness only extends to the depth of the teeth, and is removed with successively finer rasps with finer teeth.just like sandpaper. Rasps are really precision instruments. And those large old 3-dollar machinist files in flea markets do yeoman service on hardwood long after they are too worn to cut steel. Learn to use them, and you will never need or even be inclined to use a power sander on a sculpted surface like these.finish sanding becomes a snap.
Also note all the different file handles on the bench.some are nicely shaped.some are as ugly as toads. Like you rehabbing your own tools, they were all lathe practice from 30 years ago. And it's good to have your reject work around in the shop to look at every day.the stuff that makes your teeth itch every time you look at it.helps keep your ego where it belongs.
I finish sand the shaped handle in minutes with successive grits of 80-220. The 600 grit shown is merely used to polish occasionally as I go to reveal sanding scratches I missed. I also dampen the wood with water between each grit.it reveals scratches I missed, but more importantly, it swells the fibers in those scratches so they can be removed with little hollowing of the surface. It will also prevent the grain from raising beneath your finish when the tool gets wet for the first time. Another stock maker's trick.
With one handle completed for a model, the second and any subsequent handles can be made much faster, as there is a lot less trial-and-error eyeballing of your shaping progress. The first handle took 45 minutes to shape and sand, the second one will take 25 minutes. Don't try to go fast, take your time, and learn as you go and enjoy yourself. I'm just pointing out that with practice, this level of work can be done by hand at a decent pace.
As the Lakeside chisel in the vise is a paring-style rather than a thicker firmer chisel, I won't ever use it for striking and can make the shape of its handle a little finer. This will also serve as a tactile aid as I reach for them during work without looking.
One nice-to-have tool for this work is a file with a "safe" or untoothed edge to mold those epoxied shoulders nicely.
The finishing materials I'll use on the handles are Brownell's "English Red" diatomaceous earth oil-based stock stain and filler and Birchwood Casey Truoil, a linseed-based soft exterior varnish.
After buffing the new handles with a paint store tack rag and readying a holder for them, I thoroughly mix the stain-filler.
.and apply the material thickly and allow a few hours for it to set up to a hard paste.but not rock-hard.consistency. Then I buff across the grain with a coarse rag, removing the surface paste but also rubbing it deep into the mahogany's open pores. I then set the work back in the holder to dry overnight.
The next day I buff with a soft rag and coat with Truoil varnish mixed with a couple drops of art store Cobalt Drier is applied. The heavy metal drier is useful because the new finish has to amalgamate chemically with the stain-filler.makes drying time a whole lot quicker. Truoil is a proprietary linseed product and more a soft exterior varnish than an oil finish.I like it for a finish on hard-used wood because it is renewable. It's soft and wears off, but there's never a need to destroy that lovely age patina with strippers.merely buffing with fine steel wool and more coats renews the finish. And for those who prefer only oil finishes on tool handles, try this material - has the same blister-free feel as oil with more body and depth and without the dirt accumulation.
Were this mahogany a high-end job to be finished with Tung or Behlen's Bartop Varnish, I would add an additional step after grain filling I omitted here.gentle machine polishing on a loose muslin wheel with Tripoli followed by White Rouge polishing compounds.adds a depth to the work that approaches priceless age patina. As these handles will get a lot of handling and hard use in short order, I don't really need to create artificial patina for them.
I put on 4 coats of Truoil in a day, heating the handles with the heat gun to hasten drying. Each coat is rubbed with 0000 wool all the way back to the wood surface to insure the grain is fully filled and the finish surface is perfectly smooth.
While the last coat of finish is curing, I buff the steel with Knifemaker's Green and the brass with Tripoli polish. The steel is degreased with TCE and three coats of Brownell's Oxpho Blue are applied.this steel stains stubbornly and I buff between coats with degreased steel wool.and buff the final coat with a coarse brown paper towel.
My last task with metal is to finish hone the blades. It doesn't matter whether you use sandpaper/glass, waterstones, Arkansas stones or carborundum stones.... all can be made to work well and easily.... I see more need to practice rather than to spend big bucks on "systems".
I use the set of 4 Arkansas stones because I have them...but were I starting from scratch, I'd merely have my glass shop make up a half dozen thick glass plates and I'd use plain old alum oxide wet-or-dry paper mounted with spray adhesive (cleaned with razor-blade scraper) and lubed with WD-40. That's what I do for plane bottoms to overcome the stone's lack of width.
You can buy a honing guide or simply memorize your angles using your kid's plastic protractor to set them. Clamping your sharpening media to a bench set at belt height or just below will facilitate maintaining your bevels without putting some rocker in them when freehanding.although a little rocker in your bevels is no big deal and you will undo it in future sharpenings as you gain practice.
I begin by flattening the lower inch of the blade's back rather thoroughly through all four of my stones.then I hone the 25-degree main bevel using my coarse stones, followed by tipping the blade up to 30 degrees (softwoods) or 35 degrees (hardwoods) to put in a small secondary bevel using all four stones. Does it matter whether you use 30 or 35 degrees? Not much.shallower angles dull quicker on tough wood. But as your stones should live clamped to a corner of the bench when working, you will touch these blades up daily, anyway. Do that, and you will always have sharp tools and will soon toss your jigs in a drawer permanently.
The result should shave hair painlessly.
The final step is to rub out the cured finish. For a high-end piece and a semi-gloss finish, I would allow it to cure for 30 days while in use before rubbing out with pumice and rottenstone slurries on hard felt pads. But on these user tools, I will rub out immediately using 0000 steel wool lubed in Kiwi Clear Shoe Polish, a high-quality hard carnauba wax.and buff when dry.
The final result looks good along side their big brother, the slick. Can you tell these handles were made with eyeball and rasp rather than a wood lathe? If you know what to look for, and hold them up silhouetted against a backlight.you can.but it will take you a couple minutes.and for fun, I'll be glad to artificially age them and give even money over whether the Roadshow Twins can.
"When we build, let us think that we build forever. Let it not be for present delight nor for present use alone. Let it be such work as our descendants will thank us for; and let us think...that a time is to come when those (heirlooms) will be held sacred because our hands have touched them, and that men will say, as they look upon the labor and wrought substance of them, 'See! This our father did for us.' " --John Ruskin. Audels Carpenters and Builders Guide, 1923 Theo Audel & CO. New York.
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