Glazing Silicone vs Putty: Selecting The Right Material For Installation Processes

In the manufacturing industry, many experts and companies are faced with some tough choices. You want to make sure that whatever you make is of the best quality and can easily serve the purpose for which you’ve created it, and that means having and working with the right materials across the board. 

Today, the debate between whether to use putty caulk vs silicone for windows is raging seriously. Some believe that silicone window glazing is the best, while others think that putty just might be the most underrated product out there. 

In this article, we’ll look into the differences between both options to help you make a decision. 

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Glazing Silicone vs Putty: Material Overview

A Look Into Glazing Silicone 

Glazing silicone has pretty much become one of the most popular sealants for construction and building projects. While its major applications are for acting as a window sealing caulk or for sealing doors, the material is incredibly versatile in application. Glazing silicone is known for its durability as well, offering a weather-resistant seal that allows you to create an airtight and watertight barrier along the edges of doors and windows. 

Glazing Silicone & Its Composition 

In general, a window pane sealant made out of glazing silicone will usually come with the following components: 

Silicone Polymer

As expected, this is the primary ingredient used in making the window glazing tube. Here, you have a polymer that is made from an intricate mix of silicon, oxygen, hydrogen, and carbon. 

With the primary silicone base, you get material that is weather-resistant, durable, and very long-lasting.


Manufacturers add fillers to the primary silicone formulation in order to optimize its overall properties. In some cases, you can also have sealants that improve the material’s general texture and color. 

We at legendary tend to use silica as the primary filler, thanks to its ability to mix well with silicone and improve its strength.

Cross-Linking Agents

In the general creation of the sealant’s elastic properties, you’d need to throw in some cross-linking agents. These agents make it easy for the polymer chains to form strong and lasting bonds, while also providing that flexible texture that you get. 

Generally, platinum-catalyzed cross-linking is the most common method used for this manufacturing process. 

Adhesion Promoters

You can also find formulations of glazing silicone that come with adhesion promoters. Like the cross-linking agents, these components help to improve the bond between the primary silicone material and the add-ons that you have in the formulation process. 


Mostly in the form of metal salts, these components are added to improve the speed and efficiency of the cross-linking reaction – which, by extension, starts with the exposure of the silicone formulation to heat (heat-curing) or air (moisture-curing).


A plasticizer is added to optimize the silicone sealant’s workability and flexibility. This makes it possible for the material to take in switches in temperature without losing its ability to incorporate a seal. 

UV Stabilizers

If your silicone window glazing material is to be used outdoors, then you can incorporate UV stabilizers to help protect the material and its properties from the effects of the sun’s ultraviolet rays. 

As expected, this helps to generally improve the characteristics of the product over time. 


A general pigment is added to improve the color of the sealant. For aesthetic purposes, this is critical. And, in cases where you need transparency, you can incorporate a clear formulation to improve aesthetic appeal.

In general, the specific formulation of the glazing silicone can vary between product lines and manufacturers. Just as well, the specific applications and desired properties of the product will play a considerable role in determining what you have in your final mix. 

With its intricate build, glazing silicone provides several interesting features, including the following:

  • Weather Resistance: The material is generally designed to withstand exposure to several weather conditions. These include sunlight, rain, and switches in temperature. For outdoor applications, glazing silicone is more than appropriate.
  • Operational Flexibility: Once cured, you get an incredible level of flexibility from glazing silicone. It accommodates slight movements and settling for building components, while ensuring that it doesn’t crack.
  • Waterproofing: Glazing silicone creates a solid waterproof barrier that prevents water from coming into your gaps – doors, windows, etc. 
  • Air Sealing: Just as it does with water, glazing silicone also holds your structure from infiltration by air. As such, it cuts off draft and heat loss and improves overall energy efficiency for your building. 
  • Adhesion: You get an impressive level of adhesion to different surfaces with glazing silicone. Whether it’s wood or metal or glass – or even plastics – the material sticks pretty well. 
  • Paintability: There are glazing silicone variants that allow you to easily paint over them, thus improving the aesthetic appeal of your building. 

Types & Formulations Available 

Just as it is with the primary silicone material itself, glazing silicone comes in different variants and forms – all of which accommodate different requirements and applications. Some of the most prominent of these include: 

Neutral-Cure Silicone

This glazing silicone variant is known to be non-corrosive and non-acidic. It is primarily used for applications where you need to sealant not to corrode or damage specific materials as they come in contact with it. For both indoor and outdoor applications, the component is reliable.

Acetoxy-Cure Silicone

Seen by some as the major acidic glazing silicone variant, acetoxy-cure releases dangerous acetic acid during the curing process. To be fair, acetoxy-cure silicone is very effective. However, it can be corrosive to specific materials and might not work for all glazing tasks. 

Structural Silicone Sealants

These sealants are known for their immense strength and are built for structural applications. They hold massive loads and can be used for everything from wall systems to facades. 

Low Modulus Silicone

The low-modulus silicone sealant comes with optimal flexibility. It is especially useful in applications where you expect considerable expansion and movement – window frames, expansion joints, etc. 

High Modulus Silicone

The opposite of the option above, this variant isn’t as flexible as you might want. However, its impressive strength makes it perfect for  structural glazing applications. In cases where you need quick sealing and fixing, high-modulus silicone sealants are perfect.

Fast-Curing Silicone

You can find some silicone sealants that cure with great speed – cutting down the time needed for overall installation. They are also great for situations where quick fixing and sealing are needed.

UV-Resistant Silicone

As the name suggests, this sealant option is perfect for situations where you require exposure to the sun and its ultraviolet rays – essentially, outdoor applications.  

Translucent and Clear Silicone

When you need to maintain the appearance of a substrate, you choose clear glazing silicone. For glass-related applications, this variant is easily applied. 

You want to choose the right formulation and type for your sealant applications. And, to do that, consider the requirements of the project and your desired aesthetic features.

What is Putty?

Next, we look at caulk putty and what makes it such a popular option among many building constructors. 

Putty is a material that usually consists of a combination of different ingredients – all of which combine to create a moldable and adhesive substance that can be very effective at sealing gaps. 

Generally, formulation requirements for window sealing putty tend to vary based on the intended use for the material. However, you can find some of the following common putty types being made with the following constituent elements: 

Glazing Putty

Also known as window putty, glazing putty is used mostly for helping to repair broken window panes and to seal glass into frames. Traditionally, glazing putty is made from a mixture of chalk, linseed oil, and white lead. However, with modern manufacturing techniques now moving towards more eco-friendly trends, the use of calcium carbonate is now starting to overshadow lead. 

Wood Putty

As the name suggests, this is a putty variant that is mostly used for woodworking projects. Whether it’s filling cracks or helping to cover up any possible imperfections available in wood surfaces, you can find this putty variant being used for its operational flexibility. And for it to effectively operate, itis usually made from several materials – mostly the following:

  • Sawdust and Binder: Most of the formulations you see wil come with sawdust and wood fibers. However, resin and other binding agents can also be used to keep the particles together. 
  • Vinyl or Latex Compounds: A few other variations can also come with latex or vinyl compounds that can be shaped and stuck directly to the wood surfaces. 

Metal Putty

Like wood putty, the metal putty variant is specialized. It works mostly to tweak metal surfaces, and it is usually formulated with a base material like polyester resin that is combined with metal powder.

This intricate mix provides optimal durability and strength, allowing the putty to easily operate with metal surfaces.

Plumber’s Putty

With its use in plumbing services, this variant is known to be soft and very malleable. To achieve this unique texture, it is made with a combination of mineral fibers such as clay and limestone. This combination is further added to synthetic materials, thus creating the right feeling and texture. 

Wall Putty

Wall putty is one of the most popular putty variants available. Used in construction, it is made with white cement, ground marble, and powder. Additives can be thrown into that mix to improve the material’s physical properties as well, of course.

Epoxy Putty

This is a dual-sided adhesive putty that is made of a resin and a hardener. This combination provides a strong bond that makes the putty suitable for different applications – whether bonding, sealing, or fixing. 

Duct Putty

Also known to some as HVAC putty, duct putty optimizes ventilation, heating, and air conditioning systems, creating the perfect seal around vents and ducts. 

Putty’s Different Variations

Just as you get with glazing silicone, you can also find different variations of putty – all of which will differ based on your specific required properties and applications. 

Glazing Putty 

Applied primarily in the construction space, this is most likely the putty variant that you see the most in marketplaces. Its job is to help provide tight seals in window frames and glass.

Wood Putty

Carpenters make use of this putty formulation to fill defects that they find on the surfaces of wood products. 

Metal Putty

Here, you have a putty formulation that combines with metal surfaces, regardless of the product. It is known for its strength and bonding formulations, as well as its resistance to temperature swings.

Plumber’s Putty

This is a putty formulation that helps to create tight seals in different plumbing fixtures – pipes, sewer drains, and more. 

Wall Putty

Also used in the construction space, wall putty is used to fill any defects and imperfections that are found in walls – especially before painting. 

Auto Body Putty

Automotive body filler, as it is sometimes called, helps in the automotive industry to repair scratches and defects in body panels. It’s mostly a two-part product that contains a filler and a hardener, and it is mostly based on an epoxy or a polyester resin.

Duct Putty

Also known to some as mastic putty, this variant is used in HVAC systems to create the perfect seals around things like vents, ductwork, and other air transportation components. 

Marine Putty

The name pretty much says it all. This putty variant works perfectly if you need something to operate in underwater applications, meaning that it provides resistance to corrosion and general water entry. 

Concrete Putty

If you have a hole in a concrete surface, then this is one putty variant you want to choose. Its formulation allows it to offer impeccable adhesion to concrete, while also holding on to any strong loads that you might place on its frame. 

Glazing Silicone vs Putty: How Are They Made?

When looking into the window glazing putty vs caulk glazing silicone, one of the major differences to be spotted will be in how they are made. So, let’s dive into the intricate process: 

Glazing Silicone Manufacturing Process

At Legenday, we generally go through the following processes to make glazing silicone: 

Ingredient Preparation

First, we get all of the ingredients into the mix to ensure that we’re set to go. Remember – these ingredients include the silicone itself, possible fillers, cross-linking agents, and more. 

Mixing and Blending

Next, we take the prepared ingredients and blend them thoroughly to ensure that they are properly distributed and can achieve the right levels of consistency across the board.

Extrusion and Packaging

The blended formulation then goes through an extrusion process that shapes it into the right format – it could be a silicone pipe, a cartridge, or even a silicone tube

Quality Control

We then take samples from each batch and conduct the right quality control tests to ensure that the overall sealant is in line with your performance specifications. In most cases, these tests include measuring factors such as curing time and viscosity

Curing and Packaging

Once a material passes the necessary quality control steps, we store it in a controlled environment until it is ready to be shipped.

However, some sealants are also made to undergo the moisture-curing process, where they are exposed to atmospheric moisture and allowed to optimize their own properties.


With all prior steps completed, we push the final product out for distribution.

The Process Of Making Putty 

Generally, the process of making putty tends to be a bit more complex than glazing silicone. As you’d imagine, the best window glazing putty will be the one that perfectly fits into your desired functionality. However, the manufacturing process is usually something like this: 

Ingredients and Materials Preparation

First, you begin by selecting the ingredients that will go into the putty product. As we explained earlier, ingredients tend to vary based on what you’re looking to achieve and the required product parameters and functions. 

Once you have your raw materials, go ahead to properly mix them based on your formulation and recipe. This process is done in a mixing vessel, and it is critical if you hope to ensure an even distribution of ingredients as well as a homogenous product at the end of the day. 

Processing and Formulation

Depending on the putty type, you might need to add a few chemical additives into the overall mix. For instance, an epoxy-based putty will need additional hardeners and an epoxy resin. Just as well, water-based utilizes will need stabilizers and emulsifying agents. 

Quality Control

Now, take batches of the caulk for window glazing and move on to the quality control process. Generally, the appropriate tests will require measuring appropriate metrics and ensuring that the material fits with the window glazing dry time


Once a material passes the quality control steps, fill it into containers that are perfect for the required market – these can be cans, tubes, or any other containers. 

Storage and Curing

Remember that some types of putty will need either a drying or curing process that allows them to enter the required state. For instance, you have epoxy resin, which will cure over time thanks to the reaction between the hardener and the resin. 

Then, store the material appropriately and hold it in an environment where it will maintain its stability as you focus on distribution. 

Glazing Silicone vs Putty: Comparing Their Physical Properties

When determining caulk vs putty, you need to understand which of them will work better for your required functionalities. For this, an understanding of their physical properties and how they compare wil be immensely beneficial:

Physical Property  Glazing Silicone  Putty 
Overall Material Composition  Primary polymer (silicone), additives (fillers, adhesion promoters, cross-linkers, etc.)  Generally a mixture of binders, fillers, and additives. Varies based on the type you’re working with 
Form  Available in liquid,although you can get caulking tubes or cartridges Generally in solid or paste 
Curing Time  The moisture-curing variant can cure in hours, while some other variants will need up to a single day.  Generally varies based on the types, although it can take anything from minutes to hours.
Operational Flexibility  Highly flexible, with elasticity being maintained over time. Varies by type – some can be flexible, others can be rigid after curing.
Adhesion  Impeccable adhesion to different materials and substrates.  Vries based on type; some have impressive adhesion, while others don’t.
Weather Resistance  Perfect for outdoor use since it resists the weather, UV radiation, and changes in temperature. Also varies based on the type – some options are perfect for outdoor use, while others aren’t necessarily so. 
Weatherproofing Effective waterproofing properties, meaning that water is not allowed to infiltrate  Will vary based on the type and formulation you’re dealing with. 
Paintability  Some variants can be painted over, although curing is required. Some options are also paintable, allowing you to optimize color matching with nearby surfaces. 
Application Temperature  Generally ranges between -40°C (-40°F) and 204°C (400°F) in application. Varies by type, although it ranges from room temperature to higher pegs for heat-curing applications.
Toxicity Generally low, especially once it is cured. Some variations contain dangerous components, so you generally want to follow safety precautions.


Of course, it is important that you keep in mind that the properties for window glazing putty vs caulk will also depend on factors such as the manufacturer and the intended use.

Glazing Silicone vs Putty: Which Option Lasts Longer?

For your application, you generally need a product that can last long and which will be able to stand the test of time. With that in mind, you want to choose an option that easily has enough longevity to keep up. 

Here are some factors to keep in mind here: 

Operational Longevity 

Generally, glazing silicone does well on the longevity front, with its impressive durability and ability to last long. This is especially true for glazing applications, where the material maintains its properties for years. 

Putty’s longevity, on the other hand, will most likely vary based on the type you’re using. Epoxy-based putty is especially durable, while others might not be able to handle harsh conditions. 

Weather Resistance

We already pointed this out. Glazing silicone resists water easily, as well as other factors like temperature changes and UV radiation. 

On the other hand, putty doesn’t necessarily have the same level of weather resistance. While this once again varies based on the formulation you’re working with, you might not necessarily get the same level you’d have gotten with glazing silicone. 


Over time, glazing silicone will remain flexible. So, if you’re asking, “Can I use silicone instead of window putty over time?” you can rest assured that this is possible. 


Like the original silicone material, glazing silicone does well when you need to prevent the entry of water. When you need to maintain the integrity of your frame or window, this is more than critical. 

If you need a putty option that resists water, you might need to choose epoxy-based putty. This is really only the option that works here. 


Thanks to its ability to adhere to different substrates, glazing silicone is able to provide one of the most reliable bonds. The same is applicable to putty, so both options are relatively solid on this front. 

In summary, it is pretty evident that silicone comes out on top here. However, you shouldn’t necessarily underrate putty as well. The material can have its pros, making it an ideal choice as well.

Glazing Silicone vs Putty: Choosing The Cheaper Option

With manufacturers looking to save money at every turn, it is beyond important to ensure that you choose an option that helps you to save money when making the com[parison between glazing silicone and putty. 

So, which option takes the cake? 

Glazing Silicone

Generally, glazing silicone is sold in tubes, cartridges, and other forms that are developed based on the applications you’re working with. And, the price will depend on this formulation – as well as factors such as the quality, brand, and more. 

You also need to remember that factors such as UV resistance and weatherproofing will make your glazing silicone more expensive. Some brands can incorporate competitive pricing at the end of the day, so you might find reasonable pricing at the end of the day. 


On the whole, putty tends to be more inexpensive than glazing silicone. This is especially true for the ones operating applications such as small repairs and wood filling. 

Availability comes in different quantities, and you can find cost savings by making a bulk purchase instead. 

All in all, there are several factors that can come into play here. Basic putties tend to be less expensive than glazing silicone, but this might come at the expense of the quality. So, watch out for the option you choose overall. 

Glazing Silicone vs Putty: Material Advantages and Disadvantages

So, we’ve seen pretty much everything there is to understand about the products. Now, let’s take a recap to understand the benefits and drawbacks of the two of them:

Advantages of Glazing Silicone

  • Durability: Generally, glazing silicone is notable for its ability to last quite long. You can see it maintain its properties for years, do you won’t have any challenges with its staying long.
  • Weather Resistance: With its resistance to weather and climatic conditions, glazing silicone is perfect for outdoor use. In outdoor applications, the material works well.
  • Flexibility: This benefit means that the material will be able to hold its flexibility over time – it accommodates different building movements without showing any signs of cracking.
  • Waterproofing: This material does especially well in applications that might see water entry threatening quality.

Disadvantages of Glazing Silicone

  • Curing Time: With some types of glazing silicone, curing times might be considerably longer. So, when installing, please be patient.
  • Price: You will most likely have to make more of an investment in high-quality glazing silicone; especially compared to putty.
  • Cleanliness: The general application process of this material can be a bit messy overall. 

Advantages of Putty

  • Versatility: You can find putty in different formulations, so applicational versatility is easily one of the biggest benefits. 
  • Cost: As you can imagine, putty tends to be more affordable than glazing silicone. 
  • Ease of Use: Considering that the material doesn’t necessarily need any special tools to be worked with, ease of use is an added benefit here. 
  • Quick Curing: Most putty variants cure quickly, allowing you to complete your task in short order. 

Disadvantages of Putty

  • Durability: Varying longevity means that you might not necessarily get the type of long-term application you need from putty. 
  • Weather Resistance: The same factor comes in when you consider weather resistance. Some putties work for outdoor use, while others don’t

At the end of the day, both products have their pros and cons. An understanding of what you’re trying to achieve is therefore important as you hope to make a decision. 

Glazing Silicone vs Putty: How Do I Choose?

When making a choice between glazing silicone and putty, you want to put several factors into consideration for your project. As such, keep an eye on some of these factors generally: 


As expected, your primary purpose for choosing a material should come first. Whether you’re looking to seal glass into a window frame or repair a metal surface, you can make a decision from there. 

Material Requirements

Once you know what you’re trying to do, it becomes generally easier to understand the specific properties you need from the material itself. And, whoever material fits into that bill should definitely be your choice.

Environmental Factors

We recommend that you keep an eye on the environmental conditions that your chosen material will be exposed to as well. This plays a major role in determining its longevity. 

Budget Constraints

Consider your budget to determine just how much you’re willing to spend, and select a material that fits into this. Remember – quality always trumps price. 

Ease of Use

You also need to consider your level of comfort with the material as well as any additional tools that might be required to process your application. 

Material Options

As we already pointed out, glazing silicone and putty come in different material variants and formulations. So, look through the available options to see which works best for you. 

Seek Professional Advice

If you need any additional counsel, feel free to reach out to us at Legenday. We already provide the highest quality materials, and we can go even one step further by offering the right counsel to you as you make a decision. 


Choosing between glazing silicone and putty for your window glazing caulk is one challenging decision. However, a cursory examination of the metrics should help you to make a better decision. 

Whatever you choose, rest assured that we at Legenday are here to ensure that you get the right material input when you need it. Give us a call today, and let us know what you need. 

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