Putty Knife: Your Ultimate Guide to Handle Construction & More

by Joost Nusselder | Updated on:  June 11, 2022
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A putty knife is a specialized tool used when glazing single glazed windows, to work putty around the edges of each pane of glass. An experienced glazer will apply the putty by hand, and then smooth it with the knife.

In this article, I’ll discuss everything you need to know about putty knives and how to use them safely. I’ll also share some of the most common types. Let’s get to it! Content can be found in the next section.

What is a putty knife

Putty Knife Types and Their Uses

When it comes to putty knives (best ones reviewed here), there are a number of different types and versions available on the market. Depending on your needs and the nature of your work, you may find that one type of putty knife is better suited to your needs than another. In this section, we’ll take a closer look at some of the most common putty knife types and their uses.

Straight Blade Putty Knives

Straight blade putty knives are the most commonly used type of putty knife. They come in a variety of widths, typically ranging from 1 to 4 inches. The flat, straight blade is useful for spreading and scraping materials on flat surfaces. They are great for scraping off old paint, removing wallpaper (here’s how to), and spreading putty or spackle. They are also lightweight and easy to handle, making them a popular choice for both professional and DIY use.

Plastic Putty Knives

Plastic putty knives are a cheaper and lighter alternative to metal putty knives. They are commonly used for applying and spreading putty or spackle, but are not recommended for scraping or removing materials. They come in a variety of shapes and sizes, and are a good choice for those who need a basic tool for occasional use.

Carbon Steel Putty Knives

Carbon steel putty knives are a higher-end option for those who need a more durable and long-lasting tool. They are typically more expensive than plastic putty knives, but are also more effective at scraping and removing materials. Carbon steel putty knives come in a variety of sizes and shapes, and are a good choice for those who frequently work with wet or heavy materials.

Wood Handle Putty Knives

Wood handle putty knives are a classic choice for those who prefer the feel of a traditional tool. They are typically made with a carbon steel blade and a wooden handle, and come in a range of sizes and widths. Wood handle putty knives are a good choice for those who want a professional-grade tool that is both functional and aesthetically pleasing.

Handle Construction: Choosing the Right Handle for Your Putty Knife

When it comes to putty knives, the handle is just as important as the blade. Here are some things to consider when choosing a handle material:

  • Weight: A heavier handle can provide more control, but it can also make the tool more difficult to use for longer periods of time.
  • Comfort: Look for handles that are cushioned or contoured to reduce stress on your thumb and hands.
  • Strength: Handles made from polypropylene or carbon provide extra strength and durability.
  • Grip: Handles made from plastic or rubber provide a good grip, even when working with wet or slippery surfaces.
  • Color: While color may not matter to everyone, it can help you quickly identify your putty knife in a crowded toolbox.

Size and Shape: Finding the Right Fit

The size and shape of your putty knife handle can make a big difference in how easy it is to use. Here are some things to consider:

  • Length: Longer handles provide more control, while shorter handles are easier to maneuver in tight areas.
  • Width: A wider handle can be more comfortable to grip, but it can also make the tool more difficult to control.
  • Shape: Look for handles with a broader shape to accommodate larger hands, or a more advanced design for professionals who require extra control.

Safety Features: What to Look For

While safety features may not be the first thing you think of when purchasing a putty knife, they can make a big difference in preventing injury. Here are some options to consider:

  • Partial tang: This refers to a blade that does not extend the full length of the handle, which can reduce the risk of breakage.
  • Screw-on blade: Some putty knives come with a screw-on blade, which makes it easier to replace a damaged blade without having to purchase a whole new tool.
  • Contoured handle: A contoured handle can reduce stress on your thumb and hands during extended periods of use.

The Pros and Cons of Different Handle Materials

There is a great variety of putty knives available on the market, and each type of handle material has its own pros and cons. Here are some things to know:

  • Stainless steel: Provides a high level of strength and durability, but can be stiff and difficult to control.
  • Plastic: Provides a good grip and is generally lightweight, but may not be as durable as other materials.
  • Polypropylene: Provides extra strength and durability, but may be heavier than other materials.
  • Carbon: Provides extra strength and durability, but can be heavier than other materials.
  • Cushioned: Provides extra comfort during extended periods of use, but may add extra weight to the tool.

When looking for the ideal putty knife handle, it’s important to determine what you need and what you want. By considering the material, size and shape, and safety features, you can make sure you choose a handle that will make your work easier and more efficient.

Spreading and Applying Compounds with Your Putty Knife

When it comes to spreading and applying compounds, the type of putty knife you use can make a big difference. Different knives have different blade shapes, sizes, and materials that can affect how well they work with certain materials. For example:

  • A flexible steel blade is great for spreading wood filler (best stainable ones here) or other soft materials.
  • A rigid steel blade is perfect for scraping and removing excess compound.
  • A double-edged blade is useful for scraping and applying compound at the same time.

Choosing the Right Size and Shape

The size and shape of your putty knife can also play a role in how well it works for spreading and applying compounds. Consider the following factors when choosing a knife:

  • A large blade is good for covering a large surface area quickly.
  • A narrow blade is perfect for getting into tight spaces.
  • A rounded edge is great for smoothing out compound and creating a perfect finish.
  • A pointed end is useful for getting into corners and other hard-to-reach areas.

Using Proper Technique

No matter what type of knife you choose, proper technique is key to getting the job done right. Here are some tips to keep in mind:

  • Use a smooth, even motion to spread the compound.
  • Apply enough pressure to ensure the compound sticks to the surface.
  • Use the edge of the knife to scrape away excess compound.
  • Fold the excess compound back into the can to save money and reduce waste.
  • Keep your knife clean and dry to prevent rust and other damage.

Exploring Different Features

If you’re in the market for a new putty knife, consider some of the following features that can make the job even easier:

  • A pocket on the handle for storing extra blades.
  • A comfortable grip for easy handling.
  • A solid construction for added durability.
  • Attached blades that can be replaced easily.
  • Different styles and shapes for a range of applications.

Scraping with a Putty Knife: A Delicate Art

When it comes to scraping with a putty knife, the blade is everything. The steel used in the blade is typically harder than the material being scraped, allowing for effective removal of residue. The edges of the blade can be chiseled or ground to different angles, depending on the application. Experienced users may prefer an angled edge for scraping in tight areas, while a fully flat edge is better for spreading and smoothing thicker materials.

Handle and Metal

The handle of a putty knife can be made of plastic or metal, with metal being the more durable option. A specialty feature of some putty knives is a brass striking cap on the handle, which allows the user to run a hammer lightly over the blade to coax it through tougher materials. The metal used in the blade can also vary, with stiffer blades being better for removing dried residues and softer blades being better for spreading and smoothing volatile materials.

Removing Residue

Scraping with a putty knife is often used for removing residue from delicate areas, such as single glazed windows. When working with these areas, it’s important to use a specialized putty knife with a flat, stiff blade. This will help to avoid damaging the glass or the surrounding material. Modern insulated glazing may use other ways of securing the glass to the window frame, but a putty knife can still be useful for removing dried residues from the edges.

Spreading and Smoothing

In addition to removing residue, a putty knife can also be used for spreading and smoothing thicker materials. When working with these applications, it’s important to choose a putty knife with a softer blade, which allows for more flexibility and control. The blade should also be fully flat, allowing for even spreading and smoothing of the material.

Choosing the Perfect Putty Knife: What You Need to Know

When it comes to putty knives, the blade is the most important part of the tool. You want to choose a knife with a strong, durable blade that can handle tough materials without breaking. Steel blades are the most common and are suitable for most jobs, but if you’re working with sensitive materials like wood or art compounds, a nylon blade may be a better choice. You should also consider the blade design, whether it’s straight or angled, as this can affect the scraping performance.

Check the Handle Construction

The handle of a putty knife is also important, as it affects how comfortable and convenient the tool is to use. Look for a handle that is solid and easy to grasp, with a comfortable grip that won’t cause your hand to tire during long periods of work. A double handle is an excellent alternative for those who worry about their grip, and it’s also convenient for those who need to apply more pressure when scraping.

Look for a Quality Edge

The edge of a putty knife is what allows you to achieve a smooth, clean finish when scraping or spreading materials. Look for a knife with a sharp, high-quality edge that won’t break or wear down easily. A chiseled edge is an excellent choice, as it includes little teeth on the bottom that help it dig into paint and other surface compounds.

Consider the Price and Lifetime

Putty knives are available at a variety of price points, from fairly cheap to quite expensive. While it’s tempting to choose a cheaper option, keep in mind that a higher-priced knife may last longer and perform better in the long run. Look for a knife with a lifetime guarantee, as this indicates that the company stands behind its products and is confident in their quality.


So there you have it- all you need to know about putty knives. 

They’re great for a variety of tasks, from painting to drywall and even carpentry, so it’s worth having one around the house. 

So, what are you waiting for? Go get yourself a putty knife and get to work!

I'm Joost Nusselder, the founder of Tools Doctor, content marketer, and dad. I love trying out new equipment, and together with my team I've been creating in-depth blog articles since 2016 to help loyal readers with tools & crafting tips.