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We in contrast 14 strategies to discover the quickest manner to put together this useful gizmo.

Editor’s observe: this text initially appeared within the February 2007 concern of Popular Woodworking

Scrapers are probably the most misunderstood however helpful instruments in a woodshop. A scraper in its fundamental kind is solely a chunk of hardened metal with a small hook that’s created by urgent on the instrument’s edge with a fair tougher rod of metal. This instrument is able to making tear-out free cuts in hardwoods that no aircraft can handle.

But how to sharpen a scraper is a mysterious or complicated course of for a lot of woodworkers. One motive for the confusion is that there are lots of completely different printed methods on the market, lots of them providing conflicting recommendation.

So I compiled an inventory of 14 completely different methods for sharpening this rectangle of metal which were printed since 1875. All of the 14 methods principally agree that there are three steps to sharpening a scraper: Filing the sting of the instrument, eradicating the file marks with a sharpening stone after which creating the hook (typically referred to as the burr) with a hardened rod of metal, normally referred to as a burnisher.

But not one of the accounts agree on the main points. Should you file the sting of the scraper with the file parallel to the sting or at an angle (and in that case, what angle)? What form of file must you use? Should you stone each the sting and faces of the instrument? To what grit? And how ought to this be performed?

Do you could have to burnish the faces of the instrument earlier than turning the burr of the scraper? If you do, what angle do you employ? And how must you burnish the sting to create the hook? At what angle? Do you slide the burnisher alongside the sting as you flip the burr?

So one weekend I attempted all these methods then in contrast the outcomes. I used high-quality scrapers from Lee Valley, Bahco (previously Sandvik) and Lie-Nielsen. All of the printed methods principally labored and created a instrument that made shavings. Yet some methods have been quicker, some required fewer hand abilities to grasp and a few made a hook that basically grabbed the work.

After attempting these methods, making use of my very own coaching and speaking to an skilled on metal tooling, I believe I’ve discovered a 15th manner to sharpen the instrument that doesn’t require quite a lot of tools, and is quick and is straightforward for rookies.

Like Any Tool’s Edge

What’s necessary to perceive is {that a} scraper is like every reducing instrument and it responds to your sharpening efforts in the identical, predictable manner.

A sharp edge is the intersection of two metal surfaces (in a chisel, it’s the bevel and the face, which is typically referred to as the again of the instrument). Any innovative is at its sharpest when these two surfaces meet on the smallest level attainable.

The edge turns into extra sturdy because it will get extra polished by greater grits. Polishing removes tiny scratches within the metal, and scratches are the locations the place the sting begins to break down and grow to be boring.

A tougher metal may contribute to a extra long-lasting edge. However, whether it is too onerous it may be fragile and vulnerable to shock.

All these guidelines apply to scrapers. The reducing fringe of a scraper is 2 surfaces: the sting and the face. The extra polished these two surfaces are, the extra sturdy and sharp the sting is. So with that precept in thoughts, right here’s the considering behind my scraper-sharpening method.

Step 1: File the Edge

A everlasting marker will enable you decide if in case you have filed the sting sufficiently. Once the colour has been eliminated, you’re prepared to stone the sting of the scraper.

The fringe of the cardboard scraper must be filed sq. to the instrument’s faces (all of the sources agree on this). You ought to use a advantageous file. Look for one with single rows of parallel tooth (that is referred to as a single-cut file) and tooth which are advantageous, normally labeled “second cut” or “smooth.” Scrapers are delicate and simple to file, so a rough file will create deep scratches which are tough to take away.

Two or three passes with a file is normally all it takes. Use solely a push stroke with a file and use the fingers of each arms to maintain your submitting jig’s fence flat in opposition to the scraper.

Color the sting of the instrument with a everlasting marker. This will enable you to see the place you’re reducing. When the colour is gone, the submitting is completed.

You could make a superbly good submitting jig from a scrap of hardwood as proven right here. Cut a kerf within the block that permits the file to be held with a agency friction match.

How you maintain the file in use is in dispute. You can work with the file parallel to the sting, perpendicular to the sting or anyplace in between. All can lead to a sq. edge, however there is just one method that offers excellent outcomes each time no matter your talent with submitting: Use a jig, both business or shopmade.

After two strokes with the file, the colour is sort of gone from the sting.

Veritas makes an affordable jig that I like. You additionally can buy a classic noticed jointer, which was used to file handsaw tooth down for reshaping. Or you’ll be able to minimize a kerf in a block of wooden to maintain your file. Freehand submitting is nice if you’re expert at it. Most of us usually are not, so I like to recommend a jig.

Step 2: Stone the Tool

There are some ways to stone an edge. This “2″ x 2″ x 5″ block is what I choose. You can transfer the block as you rub the scraper in opposition to the stone, which spreads the wear and tear out in your stone. Alternately, with thick waterstones you need to use the facet of the stone and help the scraper with a block of wooden.

After submitting, you clean away these scratches with a sharpening stone or two. Some sources say you could have to stone solely the slender fringe of the scraper. Others say you stone each the sting and the faces. Because we now know {that a} good edge is the intersection of two polished surfaces, you need to stone each the sting and face.

How do you stone the sting? You can rub the instrument on edge in your stone, however this may make it tough to stability the instrument. Some printed accounts suggest sandwiching the scraper between two blocks of wooden for extra help, however you’ll normally find yourself abrading the wood blocks greater than the instrument.

Alternately, you’ll be able to bow the scraper as you rub it on the stone to unfold the sting out over extra of the floor. This works effectively with versatile scrapers however is kind of tough with the thicker ones.

Hold the ruler with one thumb or it’s going to slide. Use your different hand to stroke the sting in opposition to the stone. The wooden block improves management.

Instead, I like to hone the sting of the scraper on the sharpening stone with a single block of wooden supporting it from the facet. I’ll sharpen on the face of the stone as proven at proper. This is foolproof and permits you to unfold the wear and tear out throughout the stone’s face by transferring the block of wooden.

With the sting stoned, how do you stone the 2 faces of the instrument? Here is the place the actual trickery begins. Every different method that discusses this has you rub the face of the instrument to and fro on the stone. This works, but it surely takes some time. The face of a scraper is quite a lot of metal to take care of. Most woodworkers do what they will on the faces and quit after they get bored. And that doesn’t minimize it.

Why sharpen a bunch of metal you aren’t utilizing? So I took a web page from the playbook of David Charlesworth, a British craftsman. He sharpens the unbeveled face of a aircraft iron by propping up the again of the instrument on a skinny ruler set on the stone. This method, referred to as the ruler trick, sharpens solely the part of metal up by the innovative.

The ruler trick sharpens the scraper solely at its innovative, saving a lot effort and time.

Would this work with card scrapers, I puzzled? It does. And brilliantly. You sharpen solely the steel up by the sting. It takes far fewer strokes. And the slight  change in edge geometry has no discernible impact on the ultimate innovative. Thanks David.

The different query is what grit of stones you need to use. This is actually up to you. The extra polished the sting, the extra sturdy it is going to be in use.

I begin by marking the face with a everlasting marker. First work the instrument with a rough stone, comparable to a #1,000-grit waterstone. Then go straight to any advantageous sharpening stone, comparable to #4,000, #6,000 or #8,000 grit. Oilstones or sandpaper are advantageous choices as effectively. To enhance your grip on the instrument, you’ll be able to affix a strip of  14” x 14” x 6″ scrap to the scraper with double-stick tape. Or unfold a skinny layer of silicone rubber on the strip of wooden and let it treatment. The cured silicone makes the wooden grippy (so long as it doesn’t get moist).

Step 3: Burnish the Tool

Rub your burnisher flat in opposition to the scraper 5 – 6 occasions. This work-hardens and consolidates the fabric. And it attracts out the metal on the edge, making it simple to flip the hook.

Of the 14 scraper-sharpening methods I attempted, eight advisable burnishing the flat face of the scraper earlier than burnishing the sting to flip the hook/burr. The explanations for why you burnish the flat face of the instrument have been assorted: To soften the steel, to harden the steel, to consolidate the steel, or to warp the steel over the sting so you’ll be able to flip it right into a burr.

So I did what any mind-muddled journalist does: I referred to as an skilled. Ron Hock runs Hock Tools and sells all kinds of substitute aircraft irons.

Here’s what Hock concluded: Burnishing the flat face of a card scraper does two issues: It work-hardens the steel by compressing the crystal construction of the metal. The burnisher is tougher than the scraper. Burnishers will usually be of a Rockwell hardness (Rc) of 58 to 60. Modern scrapers are usually Rc 48 to 53. The tougher burnisher will compress the metal of the softer scraper, making the metal tougher and doubtless extra sturdy in use. Burnishing the face is very helpful with outdated scrapers, which have a Rockwell hardness that’s decrease, extra like within the mid-40s, Hock mentioned. (Scrapers have been usually made out of outdated noticed blades within the early days.)

A jig such because the Veritas Variable Burnisher permits you to flip a hook with little probability for error. If you’re having problem with burnishing freehand, this is a superb possibility.

The different factor that the burnisher does is to draw the metal off of the face of the scraper. Essentially, it strikes the steel so the metal makes a small level the place the face meets the sting. Why is that this necessary? It makes the scraper’s burr a lot simpler to flip while you burnish the sting of the instrument. You can flip the burr in fewer strokes and with out a lot downward strain on the instrument.

Hock’s factors about metal slot in completely with my expertise in the course of the 13 years I’ve sharpened card scrapers. Must you burnish the face to get a burr? No. But in the event you don’t burnish the face, the burr is tougher to flip, and you could use extra strain or extra strokes. Using extra strokes or strain can introduce error and create an irregular burr.

After three passes with the burnisher utilizing delicate downward strain, really feel the sting for a hook as proven. It ought to really feel like a tiny lip that your fingernail may nearly seize.

Point two: Burnishing the face creates (in my expertise) a burr that lasts longer. Hock means that it is because the metal has been work-hardened by the burnisher earlier than turning.

Once you burnish the face, you could have to flip the hook with the burnisher by operating the burnisher throughout the sting. Like with all issues with card scrapers, there may be debate. At what angle ought to the burnisher be held in opposition to the sting: 0°, 5°, 10°, 15°?

Should you employ mild strain? Heavy strain? How many occasions must you draw the burnisher throughout the sting? Some accounts say you burnish first at 0° after which burnish once more at a slight angle. (I’ve performed it this manner for years. It works, however so does skipping the step. See what works for you.)

I’ve all the time been stymied by the query of the ultimate hook angle, so I attempted slightly experiment and ready a scraper with 4 completely different hooks (5°, 7°, 10° and 15°) made utilizing the Veritas Variable Burnisher. Then I gave the scraper to Senior Editor Bob Lang and requested him to use it as I watched, and we then mentioned the completely different working traits of the 4 hooks.

Burnishing freehand is hard for some and a cakewalk for others. Here’s a tip: Rest one hand on the bench to management the angle of burnishing. Use the opposite hand to draw the burnisher alongside the sting of the scraper. This normally helps improve your management.

The standard knowledge is that the steeper the hook, the extra aggressive the instrument (15° is meant to be for eradicating paint; 0° is meant to be for marquetry). But the reality is, we may get wonderful outcomes with all the perimeters. You may get the wispiest shavings with a 15° hook in the event you used mild strain. In truth, the one scraper that appeared to carry out considerably completely different is one which I ready with no hook. That one took solely mild shavings.

So how a lot strain must you use when burnishing? I exploit strain that’s comparable to while you “spread butter on bread,” an apt description by woodworking writer Graham Blackburn.

Should you employ one stoke? Two strokes? More? I stroke the sting till I can really feel a burr. Then I cease. This takes two or three strokes.

I once more suggest a jig for the burnishing, particularly in the event you’re a newbie or aren’t ready to keep in follow along with your burnishing. I’d by no means used a jig till a pair years in the past, and I’d by no means had issues with freehand burnishing both (however I sharpen lots). The jig provides you pace and consistency. You don’t have to give it some thought, you simply do it. And errors are uncommon.

Most sources suggest including a drop of oil to the sting earlier than burnishing to forestall galling. What’s galling? That’s while you pressure steel components collectively (screw threads are a standard instance) and there may be a lot friction that the excessive factors warmth up and trigger tiny welds on the excessive factors that then break off, making the nook really feel tough. I’ve performed this, however I had to strive to do it to make it occur. I oil the sting as a result of it makes the burnisher slide sweetly.

Using the Scraper

To start scraping, I flex the cardboard scraper only a bit on the middle and maintain it at a angle to the work that’s normally between 60° to 65° to the floor. I modify my wrists till the scraper begins to minimize shavings. If you’re getting mud as an alternative, modify your angle first. Then test your hook to see whether it is nonetheless there. A hook seems like a lip on the sting.

Scrapers are nice for eradicating tear-out, however you do have to watch out not to create a melancholy that may present up after ending. When you’re employed a small space, it’s finest to then mix in that low spot with the world round by working the wooden round your drawback space with the scraper as effectively.

Scrapers are refined instruments and are able to a large number of duties. In truth, there are much more makes use of for a scraper than there are methods to sharpen it – and that’s saying one thing.

Suggested Supplies

Lee Valley

Veritas variable burnisher

Veritas jointer/edger

super-hard milled scrapers,

Lie-Nielsen Toolworks 

set of two scrapers

Woodcraft 

Pfeil burnisher


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