Skip to main content
Home › Guides › Roofing tools › Putty knives and scrapers
Guide · Scraping and prep · Putty knives, scrapers, razor scrapers and drywall knives

Is a putty knife a scraper, and what do you use instead of one? Putty knives vs scrapers vs taping knives, flexible and stiff blades, razor scrapers and single-edge blades, carbide scrapers, scraping paint and roofing adhesive, and sharpening

A putty knife is a narrow (1-1/4 to 4 inch) flexible or stiff blade for applying and smoothing filler; a scraper is the same shape with a stiff, usually beveled blade for removing material; the trade sells both under both names and a stiff putty knife is a scraper. A wide putty knife (6 inches and up) is a taping knife or joint knife and is for drywall mud; a drywall knife is the same thing. For removing paint, glue, roofing adhesive and gasket material the real tools are a long-handled floor scraper with a replaceable 4 or 8 inch blade, a razor scraper with single-edge blades for glass and smooth surfaces, and a carbide scraper for paint on wood. Instead of a putty knife, a flexible scraper, a plastic spreader, a margin trowel or an old credit card spreads filler; a stiff putty knife, a razor scraper or a 5-in-1 tool removes it.

Bayshore Safety. Industrial safety, roofing tools and jobsite supplies since 2017. · Current as of November 2026 · the C&R blade and knife product data on this site (CR-113 heavy-duty scraper with 4 in blade and 12 in handle; 4 in scraper blades in 10 count tubes and 100 count boxes; 8 in scraper blades 0.035 in thick 3 per tube; heavy-duty razor scraper; single-edge razor blades 100 count; economy drywall knife; flexible scraper; hobby knife blades); the putty knife and taping knife widths and stiffness grades as the hand-tool trade labels them (stiff and flexible, 1-1/4 to 6 in putty knives, 6 to 14 in taping knives)
Scrapers, blades and knives we stockAll roofing tools
C&R CR-113 Heavy Duty Scraper, 4 inC&R CR-113 Heavy Duty Scraper, 4 inThe product data lists the CR-113 as a heavy-duty scraper with a 4 in blade and a 12 in handle
$98.56See the product

Sorting the knives. There is a putty knife on every truck and it is used for everything, which is why people ask whether it is a scraper, what the wide one is called, what to use instead, and how to get the dried spackle and rust off it. The honest division is by blade stiffness and width: flexible blades spread, stiff blades scrape, narrow blades fill, wide blades tape. Past the putty knife are the tools built to remove things: razor scrapers with disposable single-edge blades, floor and roof scrapers with replaceable heavy blades, carbide pull scrapers, and the 5-in-1 painter’s tool. The cards below take the questions as they are asked, including the roofing uses (old adhesive, butyl, mastic and coating on metal and membrane).

Putty knives and scrapers, question by question

Blade sizes and counts are from the product data on this site; the stiff vs flexible and width conventions are the trade’s.

Is a putty knife a scraper, and what is the difference?A stiff putty knife is a scraper; a flexible one is a spreader. Both are a square-ended steel blade in a handle, 1-1/4 to 4 inches wide. The putty knife as sold has a thinner, springier blade for working filler into a hole and leaving it flush; the scraper has a thicker blade, often with a ground bevel on the leading edge and a hammer-capable end on the handle, for lifting paint, caulk, gasket and adhesive. Most crews carry one of each in 1-1/2 and 3 inch. The 5-in-1 (or 6-in-1) painter’s tool is a stiff scraper with a curved roller-cleaning edge, a point for opening cracks and a nail-pulling notch.
What is a wide putty knife called, and is a taping knife the same as a drywall knife?A wide putty knife (6 to 14 inches) is a taping knife, joint knife, drywall knife or broad knife; the names are interchangeable and all mean the flexible wide blade used to spread and feather drywall joint compound. Widths: 6 inch for the first coat over tape, 8 to 10 for the second, 12 to 14 for the finish coat, and the curved (bowed) blades are made so the center lays mud slightly proud while the edges feather, which is why drywall knives are curved. A drywall knife also means the trowel-handled drywall knife; our DRYK is the economy drywall knife.
What size knife to tape drywall, and what is the purpose of a taping knife?A 6 inch knife lays the tape into the first coat of mud and squeezes it out; an 8 or 10 inch covers the tape and the fasteners; a 12 inch feathers the final coat so the joint disappears. The taping knife’s purpose is to spread compound in a controlled thickness and feather its edges; its flexibility is what makes the feather. Can you cut through drywall with a knife? With a utility knife, yes: score the paper face, snap the board, cut the back paper. A drywall knife does not cut drywall; a drywall saw and a utility knife do.
What can I use instead of a putty knife, and instead of a paint scraper?To spread filler: a flexible plastic spreader, a margin trowel, a plastic putty knife, a 3 inch taping knife or a stiff card. To scrape: a stiff putty knife, a razor scraper, a 5-in-1 tool, a wood chisel held bevel up (for small areas), a carbide pull scraper, or a floor scraper on a long handle for anything bigger than a windowsill. For paint on wood the tools are a carbide scraper (a tungsten carbide blade pulled toward you, sharpened rarely), a heat gun with a stiff scraper, or a random-orbit sander for the last of it; a power paint scraper (oscillating) is fast on flat trim and gouges on anything else.
What is a scraper blade used for, and what is a heavy-duty scraper?The 4 and 8 inch scraper blades (ours in 4 inch 10-count tubes and 100-count boxes, 8 inch three to a tube at 0.035 inch thick) fit the long-handled floor and roof scrapers: lifting old tile adhesive, roofing adhesive, membrane residue, mastic, dried roof coating on metal, ice from a deck, paint from a slab, and gum. The heavy-duty scraper (CR-113, 4 inch blade on a 12 inch handle) is the hand version for parapet caps, flashings, gutters and anywhere a long handle will not swing. The blade is turned when one edge dulls and replaced when both are gone; the blades are consumables by the box.
What is a razor scraper, and what are single-edge razor blades for?A razor scraper holds a single-edge razor blade (1-1/2 inches wide, 0.009 inch thick, with a folded steel back) in a handle with a retractable or fixed blade, and takes paint, labels, overspray, sealant haze and adhesive off glass, tile, laminate and smooth metal without scratching, because the blade is thin and sharp enough to lift the film rather than gouge the surface. Our heavy-duty razor scraper and single-edge blades by the 100 are that pair. Rules: a new blade for glass (a nicked blade scratches), wet the surface, low angle, never on tempered glass with a dirty blade, and never on anti-reflective coated glass or plastic glazing. Hobby knife blades are the small #11-style blades for a hobby knife and go in a different handle.
How do I use a paint scraper, and what is the scraper for wood?Pull scrapers (carbide and the old cabinet scraper) are drawn toward you with two hands at a low angle, blade square to the grain where possible, taking the paint off in curls; push scrapers (the putty-knife type) go under a lifted edge of paint with a shallow angle. Heat first on thick paint, and a sharp edge always: a dull scraper skates and the user leans on it, which is how trim gets gouged. For wood the carbide scraper is the one that keeps its edge; a razor scraper tears wood fibers. For scraping wood itself (smoothing), a cabinet scraper with a burnished hook is the tool. The scraper used in a kitchen (bench scraper) is a different thing and is called a bench knife or dough scraper.
How do you clean a putty knife, get dried spackle off it, and remove rust?Clean it wet: scrape the blade against the rim of the bucket, wipe it on a rag, and rinse before the compound sets; mud and spackle that have dried come off with a soak in warm water and the edge of another putty knife, or by flexing the blade so the filler cracks off. Rust: a scrub with steel wool or a wire brush, then fine sandpaper, then a wipe of light oil; a vinegar soak overnight lifts heavy rust. Stainless blades do not rust and are worth the difference for anyone who works wet. Solvent-based adhesives and roof cement come off the blade with mineral spirits or the citrus remover in the roof cement guide linked below.
How to sharpen a putty knife or scraper, and why use a carbide scraper?A spreader is not sharpened; it is kept square and clean by a few strokes of a mill file across the edge. A scraper is sharpened like a chisel: file or stone the bevel (about 45 degrees for a push scraper, 70 to 80 degrees for a pull scraper) and knock the burr off the flat side. Carbide scrapers hold an edge ten to twenty times longer than steel and are sharpened on a diamond stone, which is why painters use them on exterior wood; they chip if dropped and are not used on metal.

Scrapers in plain words

  • Flexible blade spreads; stiff blade scrapes. A stiff putty knife is a scraper.
  • Narrow (1-1/4 to 4 in) fills; wide (6 to 14 in) tapes. The wide one is a taping, joint, drywall or broad knife.
  • Drywall knives are curved so the center lays mud proud and the edges feather.
  • Floor and roof scrapers take 4 and 8 inch replaceable blades for adhesive, mastic, coating and ice.
  • Razor scraper and single-edge blades for glass, tile and smooth metal; new blade for glass, wet, low angle.
  • Carbide pull scraper for paint on wood; heat gun first on thick paint.
  • Clean blades wet, flex off dried mud, steel-wool the rust, oil the steel.
  • Sharpen scrapers like a chisel on the bevel; square a spreader with a file.

Questions people ask

What is a good paint scraper for wood?

A carbide pull scraper, drawn toward you at a low angle after a heat gun on thick paint; it holds an edge far longer than steel.

What can I use instead of a putty knife?

A plastic spreader, margin trowel, taping knife or stiff card to spread; a razor scraper, 5-in-1 tool or chisel to scrape.

Is a putty knife a scraper?

A stiff one is; a flexible one is a spreader. The trade sells both under both names.

What is a wide putty knife called?

A taping knife, joint knife, drywall knife or broad knife.

How do I use a paint scraper?

Heat thick paint, keep the edge sharp, pull a carbide scraper toward you at a low angle, push a putty-knife scraper under a lifted edge.

What can you use instead of a paint scraper?

A stiff putty knife, a 5-in-1 tool, a razor scraper on smooth surfaces, a heat gun and chisel, or a sander.

What is the purpose of a taping knife in drywall?

To spread joint compound in a controlled thickness and feather its edges; 6, 10 and 12 inch for the three coats.

How do you wash a putty knife?

Scrape it on the bucket rim, wipe, rinse before the compound sets; soak dried mud in warm water.

How to get dried spackle off a putty knife?

Soak it in warm water, flex the blade so the spackle cracks, and scrape it with another knife.

How to remove rust from a putty knife?

Steel wool or a wire brush, fine sandpaper, a wipe of light oil; a vinegar soak for heavy rust.

What is the standard putty knife width?

1-1/2 inch is the common filler knife; 3 inch the general scraper; 6 inch and up are taping knives.

How to sharpen a putty knife?

Square a spreader with a file; sharpen a scraper on its bevel like a chisel and remove the burr.

Why are drywall knives curved?

So the center lays compound slightly proud while the edges feather to nothing.

What is a scraper blade used for?

Lifting adhesive, mastic, coating, paint and ice with a long-handled floor or roof scraper.

What size knife to tape drywall?

6 inch to bed the tape, 8 to 10 to cover it, 12 to feather the finish.

Is a taping knife the same as a drywall knife?

Yes; both names mean the wide flexible blade for joint compound.

Can you cut through drywall with a knife?

With a utility knife, by scoring and snapping; not with a drywall or putty knife.

What is a scraper used for in the kitchen?

That is a bench scraper or dough scraper, a different tool from the paint and floor scrapers here.

Why use a carbide scraper?

It holds an edge ten to twenty times longer than steel on paint and wood.

What is the difference between a drywall knife and a putty knife?

Width and flex: a drywall knife is 6 inches and wider and flexible for feathering mud; a putty knife is 1-1/4 to 4 inches for filling and scraping.

Related guides

Hook blades and utility bladesWhich blade cuts shingles, felt and membraneRoof cement, sealant and primerASTM D4586 and D41, and removing tarTrowelsMargin, pointing, notched and roofing trowelsHex keys, wire brushes and locking pliersSizes, bristles and clampsOSHA safety glasses requirementsWhat 1910.133 says

The ratings, test results and standards shown here are the manufacturers' published values, reproduced as published. Nothing on this page is a recommendation by Bayshore Safety that any product is suitable for a particular task, hazard or workplace. Selecting safety products and protective equipment is the responsibility of the end user and the employer, based on their own hazard assessment and the regulations that apply to their work. Confirm every value on the manufacturer's own documentation before use.

Setting up a roofing crew or a shop?Call (925) 215-7337 or email us the trades, the crew size and the quantities and we will quote tools and supplies by the case, with the part numbers listed. We sell nationwide.
All roofing tools
!
How to buyCard, purchase order or invoice terms; quotes on request; agencies and institutions welcome.
Live Service & SupportReal people who know the products, Monday to Friday 7:30am to 4pm Pacific. 925-215-7337
We DeliverWe ship nationwide. Parcel and LTL freight to job sites and businesses across the U.S.