What Is A Putty Knife Used For?

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Have you ever seen the scraper that we use for glazing windows? This scraper or spatula that we use to apply the putty and smoothen it, is also called the putty knife.

Now you can understand that this kind of knife is different from the normal knives that we use in our kitchens.

The main function of this knife is to scrape the surface and spread the putty evenly on it.

If you are interested in using the DIY tools in your home, you must have used the putty knife.

Well, you may or may not know about it, so let’s start from scratch and see in detail what a putty knife actually is, what it is used for, and how you can use the putty knife for DIY work around the home.

Without further ado, let’s dive in.

What is it?

A Putty knife is a versatile and specialized tool that can help you in carrying out simple construction tasks around the home.

According to the Wikipedia:

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.

Modern insulated glazing may use other ways of securing the glass to the window frame.

It is available in the market with various names, such as spackle, spatula and scrapers are the other names for the putty knives.

You can find the putty knives in a number of variations.

Some of the variations include:

  • Plastic, carbon steel, stainless steel, or brass blade
  • Stiff blade or flexible blade
  • Blade widths from 3/4″ to 6″ wide
  • Flat edged blade and chiseled edged blade
  • Straight edge and angled edge blade

And many others.

The functionality of these all variations depends on the task that you want to carry out with these knives.

However, putty knives are widely used for construction purposes.

The commonly available widths of these knives are from 1-1.5 inches.

However, you can also find the wide-bladed knives that have a width of up to 6 inches.

If you want to know that is the right putty size, read the upcoming section.

What are the putty knives used for?

A Putty knife is an essential component of every toolbox due to its diverse usage.

The knives with smaller blades are preferred for the most efficient tasks.

On the other hand, although the larger blades are readily available, they can not let you attain the level of perfection that you can easily obtain using the smaller ones.

Some uses are the following.

  • The knives with stiff blades are excellent for scraping purposes.
  • If you want to buy it to carry out the spreading tasks, you should go for flexible-blade knives that are typically 0.20” thick.
  • For removing decals and water sealing tasks that help in avoiding falls and slips, you should go for disposable ones.
  • These knives are made up of the recyclable handle and blade and you have to dispose of them after using them.
  • Traditionally, people used to opt for metallic ones.
  • But this trend has almost faded because metallic options have the electricity shock risks associated with them.
  • Now people prefer plastic models due to their safe usage.
  • Make sure to keep the plastic and disposable models away from heat areas, such as furnaces, stoves, burners, fireplaces, heaters, and other high heat resources
  • The ones with wide blades are used for sheetrocking purposes.
  • The ones can also be used for applying filler materials like wood filler, drywall taping compound, etc.

How to use it effectively

As we discussed earlier, these play a vital role in spreading and applying compounds.

The fact is the generic ones have a very wide functionality and you can use them for the application of almost any kind of compound.

Some of the most commonly applied materials that you can apply using the putty walls, including wood putty, fillers, base application drywall compounds, adhesives, and construction materials.

Nowadays, people are opting for two-in-one products that are not only made up of plastic but are also entirely disposable.

It shows that people are now not much interested in the continued use of the same putty knives and want to handle variations to carry indifferent tasks efficiently.

Another reason why people prefer plastic disposable putty knives is that they are cheap and available at affordable rates.

Its importance

Now, we have discussed disposable and plastic knife blades, there are other types of blades that people love to choose from for the putty knives.

Carbon steel blades

The first ones are the blades that are made up of polished carbon steel.

These blades are durable and efficient and help the DIY workers in carrying out all the spreading and applying tasks.

However, if you do not look after them properly, they can get rusted.

Stainless steel blades

If you are ready to spend a bit more money to get a high-quality product, then you should go for stainless steel blades.

These are the premium version of the blades and often easy to handless because of their stainless properties.

You can use these blades for long-term usage, and even one with a wooden handle and stainless steel can last a lifetime.

Well made steel blades

These are also the steel blades but their construction is quite artistic.

In this case, the structure is much different from the common putty knife.

The blade of well-made steel knives is narrower at the center while the edge at the handle and the leading edge is thicker.

Customer reviews and testimonials on various online selling platforms have revealed that this blade has helped them in modulating the pressure that you use while spreading the material.

How to use it

  • When you go to the market or visit the online stores, you will get confused to see the wide variety of angled blades that are available with some handsome variations.
  • The best option for you to carry out all the basic tasks is to go for the flat ones.
  • Do not buy disposable plastic putty knives if you want to carry out lengthy tasks, as they are weaker and less efficient.
  • Do not use too much putty while proceeding with the application processes.
  • While using the knife, hold it at a 30-degree angle above the hole.
  • While filling the gaps, make sure to add the extra layer of putty before using it.
  • Proceed with the vertical application and spreading of the putty while using the putty knives.
  • Do not forget to scrap the extra putty after you have finished your task.
  • While using it as a scraper, make sure to use the mask to avoid the sun and dirt.
  • You can also wear gloves and safety goggles if you want.
  • You should be more careful if you are dealing with the scraping of toxic materials such as lead paint.
  • If you see any kind of empty spots or openings on the surface, make sure to cover those weak areas first by applying relatively more amounts of putty.
  • Remember that if the material that you want to scrap is very hard, and you are not able to handle it on your own, you should either take professional help or go for Drywall knives.
  • These are the knives that are particularly designed for heavy scraping materials.
  • It is due to this reason the size of the Drywall knives is larger than the putty knives.


Can I use them for painting?

It is true that some artists use putty knives for painting.

You can use it to apply the paint on the canvas, just like the putty on the wall.

Which ones are better for spreading materials, flat or the angled ones?

The flat ones generally help in better spreading.

Moreover, while spreading, make sure to find the flexible blade as compared to the stiff one.

Can I use it to seal holes?

Sealing holes is one of the main reasons why you should use putty knives.

You can use a putty knife to apply any kind of substance to fill up the holes.

Final Verdict

This article must have increased your knowledge about putty knives.

Now you can understand in a better way it is a different class of knives that you do not use in the kitchen for cutting or slicing purposes.

The choice depends on how you are going to use it.

Last Updated on July 22, 2021

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My name is Andy Wang, and I'm a retired chef. I used to work at the City Vineyard restaurant in NYC. I also had a culinary degree from the Institute of Culinary Education in New York. And this blog is where I share my love for knives and cooking with people like you.