What is a cabinet/card/hand/wood scraper?
Cabinet scraper, also named card scraper, hand scraper and wood scraper is one of the simplest and most useful cutting tools in existence. It is a rectangular or curved piece of thin steel plate used to cut, clean and smooth surfaces. From now on in this article, I’ll refer to this tool as a cabinet scraper.
What is the purpose of the cabinet scraper?
It is used to shape, clean and finish the surfaces by cutting delicately small amounts of material. A scraper is a contradictory term, cabinet scrapers don’t scrape when set-up properly – they cut. It is a superior tool in tricky grain woods where even high pitched planes produce tear out. It is one type of plane even in its most simple card shape form. The scraper and the hands holding it form the functional plane.
What is a cabinet scraper made of?
Cabinet scraper is made from thin, flat piece of moderately hardened high carbon steel, hard enough to hold the edge, but malleable enough to create and turn the hook. Cabinet scrapers are available in various thicknesses, sizes, and shapes. The most common shape is about 3×6” rectangle. Another common shape is the gooseneck scraper, with a french curve shape which is useful for shaping and smoothing curved surfaces. Thicker scrapers are for wider surfaces and more aggressive stock removal and thinner are popular with more delicate tasks such as musical instrument making.
Cabinet scrapers are one of the cheapest tools around, even premium brand scrapers are dirt cheap.
Scraper plane called Cabinet Scraper
There is also a hand plane called cabinet scraper that is one type of scraper plane. It consists of a card scraper mounted in a frame that resembles a spokeshave. The blade is held in position by a pair of set screws and the fine adjustment of the scraper blade is made with the thumbscrew.
How does the cabinet scraper work?
Scrapers and scraping action can seem mysterious for a first timer. Many questions are raised, is that small flat piece of steel really a functional cutting tool to produce shavings like a plane? Why would anyone scrape wood? Why the scraper is angled forward and bend slightly? How does it work?
Demonstrating a well-sharpened cabinet scraper is an eye opener for many. The ease of cutting beautiful gossamer shavings from even the most hard-to-place wood will convert any skeptic.
The answer is in the minuscule burr or the hook that is rolled on the well-honed edges of the scraper with a burnisher. In the microscopic scale, the cutting geometry of the scraper blade resembles a bench plane with a well-set cap iron. The cutting action of a cabinet/card scraper is similar to high-angle smoothing plane with an angle of 60°. The scraper face immediately behind the burr acts like a very finely set chip breaker, fracturing the severed wood fibers before they can tear out. This abrupt failing of the shaving is the secret of tear-out free cut, wood fibers don’t have a chance to lever and tear up in front of the cutting edge.
When learning to use hand planes, I researched the literature on the subject. Dr. Chutarro Kato´s studies about cap irons/chip breakers was an eye-opener for me. His findings, that the closer the cap iron is to the edge the less tear out is bound to happen and when the shaving is sufficiently thin then the tear-out is altogether diminished. When I looked his drawings about the blade/cap iron assembly with the microscopic distances from the edge to the cap-iron, one thing came to my mind instantly, it resembled the scraper edge with a turned burr! The geometry of the cut and the chip displacement is almost the same. So practically you can set the ordinary plane cut like a scraper if you want to!
Cabinet scrapers can be tuned to cut differently
How to tune the cabinet scraper for a rough cut?
For a really fast rough work, a scraper is better set up by simply filing the edges and skipping the honing procedure altogether. The burr left by filing is kept and after filing the edges square, the burr is burnished out flat, and then pulled it back again. This type of serrated edge cuts aggressively and fast but don’t last long. A surface is left with microscopic marks which need to be cleaned out with the scraper set to finer cut or sanding with fine grade abrasives.
How to tune the cabinet scraper for finishing cut?
File and hone the edges and faces precisely. Aim for perfect surfaces with no scratches. Draw the burr with light pressure. Adjusting the cutting angle of the burr defines the aggressiveness of the cut, steeper the angle the more aggressive the cut. Use the burnisher at an angle of 1° to 15° to adjust the burr. For very fine cut very shallow angle is needed.
Smoothing plane vs cabinet scraper
The scraper is touted as the king of smoothing the tear-out prone woods and a great substitute for sandpaper. Shouldn’t I use it for everything if it so good and ditch my hand planes completely?
Not really. I consider them as a great team of great tools that when used together can produce superior results in every situation you are going to face.
The hand plane is still my tool of choice whenever I am sizing straight-grained and well-behaving woods, which still are the majority of work I do. The ergonomics of hand plane are really superior over the card scraper, handles are comfy and you can hog relatively large amounts of wood in a short time. A scraper is not really meant to size the wood but to finish the surfaces.
When the grain goes wild and curly then the scraper comes to rescue. Good strategy when working with a wild, curly or interlocking grain wood is to size and to flatten the surface by planing with the bench plane across the grain and finish by smoothing the surface with well-sharpened cabinet scraper with the grain. This is a fast way to create a beautiful surface.
Cabinet scraper vs sanding
Sanding is not my favorite task. Scrapers are great for replacing the sanding partially or completely. Well-sharpened scraper produces a cleaner surface than sanding. The pores of the wood are not clogged with dust, and the fibers are cut cleanly without tear-out or fuzz.
Never use cutting tools after sandpaper. If needed, sanding is to be used in the last step
Strengths of the abrasives
Using the abrasives is easy to learn. With a very little practice, you can achieve very consistent surfaces relatively fast with using power sanders and working through the grits. Sanding technique is relatively easy to learn.
Weaknesses of the abrasives
Sanding produces lots of dust. This is the most serious occupational hazard for any woodworker. Even the occasional hobbyist should take measures to limit the exposure to wood dust by using dust collection, air purifier, and good quality respirator. Airborne dust can linger hours in the air and contaminate your lungs even after you are long done with sanding. Wood dust can cause many serious health problems including lung cancer
Abrasives are disposable, you can’t reuse or sharpen them when they are worn out. Abrasives are expensive if you look at the durability and the variety of grits needed. For the best result, you need 3-5 different grits and every piece cost money.
Wood is not a homogenous material. Hardness and density between late and early grains of wood can vary a good deal, causing the sanding to remove more wood from softer areas and therefore producing an uneven surface. Carefully scraping the same wood with sharp scraper brings about level, even surface.
Strengths of the cabinet scraper when compared to sanding
The comfort of the use. Sharpened scraper makes shavings, not dust which makes it a pleasure to use. No need to use respirators or roaring dust-collection systems. Another huge plus is practicality, you don’t need to go through 3-5 consecutive grits to get a good quality surface.
With scrapers, you can easily produce flat even surface even if the wood density varies from soft to hard along the surface. But remember though that the champ of the surface flatness is still a bench plane.
Veneered surfaces are best prepared with a cabinet scrapers. 1/42” (0,6mm) veneers that are commonly used sand easily through with power sanders. The finesse and accuracy in which you can work with scrapers make it well suited for thin veneer work and inlay.
Weaknesses of the cabinet scraper when compared to sanding
The scraper is one of the hardest tools to sharpen and use properly. Learning it can be frustrating, but I promise that it is worth it!
Scrapers tend to heat up a lot due to the cutting friction and can cause blisters if used vigorously. There is a couple of ways around the problem. One is to use fridge magnet as a heat shield between the thumbs and scraper, another is to use thumbs from old leather gloves to protect the thumbs, and third is most radical, use a couple scrapers and cycle through them when the scraper gets too hot.
Using the cabinet scraper by hand does demand considerable stamina and it becomes an issue if the surface to be scraped is huge or numerous.
What are the cabinet/card scrapers used for?
Planing and smoothing tricky woods
A well-sharpened scraper is an unbeatable champ when smoothing burls, curly and figured woods, around the knots, interlocked grain woods such as sapele mahogany, leaving glass smooth blemish free surface ready for finish.
Leveling and cleaning inlays, rosettes and purfling
Delicate inlays and marquetry with countless of small pieces of various wood species and grain running in every direction and even end-grain pieces are almost impossible to clean and level with any other cutting tool than the scraper. When doing rosette inlays and purflings for a guitar I have found the card scraper to be the best and most precise tool of choice.
Cleaning glue squeeze-out
The absence of the glue squeeze out in finished furniture or musical instrument is considered as a mark of very high mastery of the skill. I have found the variously shaped small scrapers to be indispensable when building guitars. With scrapers, you can easily scrape the partially cured glue away from the joint junctions and maintain clean looks of the work.
Cleaning machine and layout marks, dirt and any defects
Shallow machine marks, layout marks by pencils, dirt and finger smears and any defects are removed in a breeze with a sharp scraper. Keep sharp scraper always on a workbench for a quick touch up work.
Removing finish or smoothing lacquers between coats,
Use the scraper with no burr when leveling lacquer or varnish between coats. Prepare the scraper as usual by filing and honing faces and edges but do not use the burnisher to turn the hook. Sharp 90° degree corner is all that is needed for leveling the lacquer. For very small defects, you can use a razor blade as a small scraper. I have found it useful to use masking tape to shield the corners of the scraper/razor to prevent them accidentally leaving marks to lacquered or varnished surface.
The best cabinet scraper?
It is hard to define the best cabinet/card/hand scraper. It is so simple tool that there is really no difference other than the steel used and the quality of edges when new. Cheapest scrapers are cut with a die and the edge is thus deformed and left for end-user to file away when first time setting it up. By spending a couple bucks more you get a scraper with ground edges which are faster to file and hone to perfection. Brands such as Veritas, Lie Nielsen, Clifton, Bahco are considered to be made with good quality steel and come with ground edges. My opinion though is that almost any flat piece of steel can be transformed to scraper by proper filing, honing and burnishing.
The best scraper is sharp and well cutting tool that is close at hand when needed.
How to use the cabinet scraper
There are a couple ways to use a scraper in hand. Generally, scrapers are held with both hands and you either push the scraper away from you or pull it towards you. The more powerful and aggressive cut is possible when pushing away and when needing more fine cut pulling motion is preferred.
Two-thumbs behind the blade grip
A common way to use scraper is to use both thumbs behind the blade to bow it. Tilt the scraper forward about 60 degrees, bow the scraper lightly with thumbs and try to make the first cut. Start to adjust the angle of cut slightly by lifting it slowly back to vertical and when the scraper starts to produce shavings that is the right angle of cut. This angle depends of the angle of the burr.
For the aggressive cuts, the thumbs are placed down just behind the cutting edge. The more you bend the scraper, the more deeply it will cut. More bend also reduces the width of the cut, and can easily produce shallow trenches if you don’t be careful. The cut is made by pushing away.
For finer cuts, move your thumbs upward toward the upper edge and don’t flex the scraper much. Let the scraper cut with an almost whole width of the blade. Cut by pushing away. With sharp scraper and fine burr, this grip is capable of making a beautiful glistening surface.
Heel-of-the-hand behind the blade grip
Very powerful way to use the scraper is to grip it in your dominant hand by placing the heel of the hand behind the scraper (in the place where you place the thumbs in Two-thumbs grip) and bending it around the heel by both hand fingers. By this grip, you can effectively cover a big area, keep couple scrapers at hand to cycle through them when they get too hot.
Cabinet scraper holder
Lee Valley Veritas have designed handy scraper holder for cabinet scrapers. It offers improved ergonomics over mere cabinet scraper by shielding the fingers from heat and bending the scraper blade with a set screw. You can work longer periods of time without burning and spraining your thumbs.
Learn more about scrapers: Cabinet scraper tips – get the most out of the card scraper