What is RTV Silicone

What Is RTV Silicone? – Guide to RTV Sealer and Adhesive

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There are plenty of sealing compounds on the market, with the most commonly used product being silicone. However, more people have been wondering, “what is RTV silicone?”, and how it differs from standard silicone that would usually be used in kitchens and bathrooms? RTV silicone is an interesting compound that has plenty of uses across a broad range of industries, so we will be taking an in-depth look at what it is and everything that it has to offer!



Explanation of RTV Silicone

RTV silicone might sound like a complex compound, but it is a simple product that can make life easier for us, whether used for a DIY project or commercial applications. RTV silicone is best described as a liquid compound that will cure when exposed to air at room temperature and eventually form a flexible rubber.

RTV silicone is available in different forms, including, Electronic Encapsulant Potting Compound, Molding Rubber, and an Adhesive Sealant.

Additionally, this silicone rubber is also available as a single-component product and as one that has been mixed from two components. 

History of RTV Silicone



Brief History of RTV Silicone

In the 1820s, a chemist named Charles Macintosh collaborated with an inventor named Thomas Hancock to enhance the method. They heated natural rubber sheeting along with waterproof rubber sheets after dissolving it in benzene. Later on, sulfur was introduced to the process. Nevertheless, Charles Goodyear is responsible for contemporary vulcanization as we recognize it. Goodyear’s invention sparked a new era in manufacturing, but his perseverance was not rewarded, and he died with over $200,000 in debt.

To honor his significant contribution to the business, the famous Goodyear tire firm was eventually named after him.

As previously stated, utilizing sulfur alone throughout the vulcanization process is inefficient, slow, and expensive, which is why rubber was not extensively utilized. This was the case until an American scientist named George Oenslager demonstrated in 1912 that introducing accelerators to the vulcanization cycle enhanced the curing process. He created vulcanization, which is still widely used today.



What Is RTV Silicone?

RTV is a form of liquid silicone rubber that vulcanizes at ambient temperature in addition to withstanding temperatures as high as 356℉.

Vulcanizing at room temperature indicates that the silicone hardens at room temperature.

If you are asking yourself, “what is RTV silicone?”, it is essentially a silicone product that is designed for intense conditions while maintaining cost-effectiveness, biocompatibility, durability, and stability.


The Importance of RTV Silicone in the Market

While it may seem unusual, RTV silicone has an important place in a broad spectrum of industries. Mold creation is an important procedure in many sectors, from product reproduction to casting and development. The intrinsic value of the materials utilized is one of the most significant criteria in assuring effective mold creation. The type of silicone RTV rubber utilized, in particular, can have a considerable influence on the finished product.

RTV Silicone for Mold Production



Explanation of the Term “RTV”

So, what does RTV stand for? RTV is an acronym that stands for Room-Temperature-Vulcanizing. This is used for silicone rubber that has been designed to cure at room temperature. Additionally, RTV consists of two types of silicone, which we will explain below.


Different Types of RTV Silicone

RTV silicone is primarily available in two types, RTV-1 and RTV-2. RTV-1 is a standard ready-to-use, single-component compound silicone. This material begins crosslinking once it is exposed to humidity. RTV-2 is a different type of compound that consists of two components that need to be mixed before crosslinking is achieved.



Polysiloxane, a curing agent, fillers, and additives make up the one-component RTV-1 silicone rubber. When the material is poured into the casting, it comes into proximity to air moisture and begins crosslinking.

Alcohol and other neutral byproducts might be produced during the process of curing.



RTV-2 silicone rubber is made up of two parts. The polymer and crosslinker are in one section, while the polymer, as well as a platinum catalyst, are in the other. After combining the two ingredients, it begins to vulcanize.

UV light can be used to flash vulcanize rubber grades.


Chemical Composition of RTV Silicone

RTV silicones are composed of silicone polymers, organoreactive silane catalysts, and fillers. Silicones are made up of a Si-O bond; however, they can contain a wide range of side chains. Silicone polymers are frequently produced by reacting dimethyl dichlorosilane and water.

Chemical Properties of RTV Silicone

Fillers like acetic acid have a quick cure time, but oxides and nitrides have superior heat conductivity. Tack-free times are commonly measured in minutes, while cure times are measured in hours.



Properties of RTV Silicone

One of the reasons for the popularity of RTV silicone is the amount of benefits that it has to offer with very few tradeoffs. To understand more about what this compound has to offer, we have taken a closer look at the various properties of RTV silicone.


Physical Properties

The only major restrictions of silicone adhesives and sealants are that they are unable to be painted over with water-based paint and that water vapor travels rather effortlessly through hardened silicone rubber.

Aside from that, these adhesives are extremely flexible and possess a broad operating temperature spectrum. They are impervious to extreme weather, mildew, humidity, and mold, and have good electrical properties.


Chemical Properties

RTV-1 silicone rubbers offer suitable solutions for a variety of bonding, sealing, and coating applications. Adhesion may vary from regulated to self-adhesion and the Shore A hardness may vary from 18 to 60. RTV silicone provides various material benefits due to its chemical composition.

RTV Silicone for Mold Making

It is a pourable, lightweight substance that vulcanizes at ambient temperature. The unprocessed product is rather inexpensive and it properly solidifies on the surface of glass, plastic, or other delicate materials without fracturing or melting them.


Mechanical Properties

Break elongation can range from 150% to 700%. RTV-1 silicones provide outstanding resistance because of their unique and strong chemical characteristics, allowing them to withstand severe weather and other hostile circumstances and age well, preserving their initial qualities significantly better than competing materials such as polymers and other plastics.



Applications of RTV Silicone

Since there is no need to ask, “what does RTV stand for?”, we need to understand what it is used for. Below we have provided information on the various uses of RTV silicone in industrial, construction, medical, automotive, and household settings.


In Industrial Settings

Both types of RTV silicone products have their place in different applications and RTV-2 is mostly used in an industrial and manufacturing setting as a sealer, adhesive and molding material.

This is due to its excellent ability when it comes to demolding, making it easier to manufacture different materials that have been cast into a mold.

As a result, it is extensively employed as a soft molding material in the reproduction and manufacture of cultural relics, antiques, toys, gadgets, and mechanical devices.

Industrial Uses for RTV Silicone


In Construction

There are several applications for RTV silicone sealant in construction. Among the most prevalent applications of silicone is filling cracks and gaps. This may be done inside as well as outside a building.

Uses in Construction for RTV Silicone

Waterproofing areas surrounding doors and windows can also be accomplished with silicone sealants. It may also be used to waterproof and a variety of other building and construction materials. It is also useful for creating a watertight seal surrounding pipes and other components.


In Medical Applications

RTV silicones make it simple to create elastomeric-tailored prototypes, which is extremely beneficial during the product’s initial design phase. RTV silicone can be used for a variety of products such as medical training aids, bandages, pellets, orthotic inserts, shoe insoles, prosthetics such as dentures, and so on. 

Medical Uses for RTV Silicone


In Automotive Applications

You will be surprised to find that RTV silicone has been used in the automotive industry for a long time. The most common use of this product is as a gasket maker, but it has a variety of other uses such as sealing windshields, repairing cracked bumpers, and repairing various leaks that pop up around the vehicle. However, many automotive experts would suggest using it as a temporary fix instead of a permanent one.

Automotive Uses for RTV Silicone


In Household Applications

RTV silicone binds well to typical domestic materials like tiles and wood. To prevent water from leaking into your home from the outside, a bead of RTV silicone sealant is often placed around the windows. Additionally, it is used in the bathroom around showers, sinks, toilets, and tubs. As cured RTV silicone is food safe, you can also use it to repair the seal on your oven door.

Household Uses for RTV Silicone



Advantages of RTV Silicone

Since we have been on the journey of learning about what RTV silicone is, we should discuss the numerous benefits that come with using this product. RTV silicone holds resistance to chemicals, UV light, and extreme temperatures.

Furthermore, it is also easy to use, incredibly durable, and versatile. This is the reason that it can be used in a myriad of industries.



RTV silicone remains one of the most widely used silicone rubbers in industrial and consumer applications. Not only can it be used as an adhesive, but it can easily be used as a gasket material, for various molds, as a sealer, and it can even be used for various crafts. The versatility of RTV silicone is incredible and it can take nearly any shape that you need, which makes it ideal to keep around for DIY emergencies.

RTV Silicone for Emergency Repairs


Resistance to Extreme Temperatures

As we have already discussed, RTV silicone has an incredibly high resistance to heat. This makes it ideal for applications in extreme conditions such as engine compartments, machinery, and harsh weather.

This resistance does not only apply to heat but to the cold as well. So, you will be able to get away with storing it in a cold area.


Resistance to Chemicals and UV Light

RTV silicones boast a 40-year lifetime and great elongation. They are also easy to dispense, even in freezing temperatures, along with being VOC compliant. Furthermore, RTV silicones possess outstanding UV and thermal stability features. Additionally, this product has great adhesive properties, is chemically resistant, and does not droop or shrink.


Easy to Apply and Cure

One of the biggest advantages of RTV silicone is that it is very easy to use. Application is similar to any other silicone product; however, the brand that you choose might have a different nozzle compared to the next. The curing process will usually start immediately but in some cases, the formula will take longer to cure.

RTV Silicone is Easy to Use



Disadvantages of RTV Silicone

Naturally, there are disadvantages that come with using RTV silicone. This includes poor adhesion to particular surfaces, being very difficult to remove once the silicone has cured, and not being ideal for structural applications. Below, we will discuss these issues.


Poor Adhesion to Certain Materials

In general, silicone RTV mold-forming rubber does not cling to anything and fails to stick to anything. It will, however, attach to itself, to similar silicones, glass, and silica.

This resistance to adhere to certain materials will present a series of problems if you try to use it as a general adhesive.


Can Be Difficult to Remove Once Cured

Once RTV silicone has cured it can be incredibly difficult to remove. However, it is not impossible as you will need to soften the silicone with a heat gun. Heat should ideally be applied to all parts of the silicone for no less than 30 seconds but not longer than two minutes. The silicone substance can then be tested to determine if it is soft enough to be removed.

RTV Silicone Can Be Difficult to Remove


Not Suitable for Structural Applications

Structural applications are not the cleanest and this will present a new problem when using RTV silicone. If there is any filth, oil, grease, or other foreign matter on the surfaces you are dealing with, making a strong and good adhesion will be difficult. Furthermore, RTV silicone will not adhere to concrete.


So, what is RTV silicone? This unique silicone formula is incredibly useful when it comes to creating an elastic and weatherproof seal. While it can take a while to get used to since it cures very quickly, there is no doubt that this will be a handy compound for any DIY enthusiast who requires a strong compound that will not crack, shrink, or crumble.




Frequently Asked Questions


What Is Room Temperature Vulcanizing?

RTV, or room temperature vulcanizing, refers to a process that affects rubber compounds such as silicone that allows them to harden at room temperature. RTV silicone allows companies to use a rubber compound that can adhere to strict requirements owing to the minimal shrinking associated with the rubber itself.


Is RTV Sealant Durable?

RTV sealant is incredibly durable, as it is radiation and UV-resistant, water-repellent, chemical-resistant, and fire-retardant. This makes it ideal for a variety of uses in different industries.


What Is RTV Silicone Sealant Commonly Used For?

RTV silicone sealant is commonly used for sealing high-temperature equipment, window plates, and sealing panels. This is because of its ability to constantly undergo thermal cycles without cracking or hardening.

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