What Is RTV Silicone? – Room Temperature Vulcanizing Silicone

This post may contain affiliate links. We may earn a small commission from purchases made through them, at no additional cost to you. You help to support resin-expert.com

For years, there have been new adhesives entering the market, offering exciting and innovative characteristics. One of the first adhesives that was widely used in a number of industries is silicone. Silicone comes in many varieties, with one of the most popular silicone types being RTV silicone. What is RTV silicone, though? Let’s have a look at what RTV silicon is, what it is used for, how it is made, and how you can use silicone type in your everyday life.

What is RTV Silicone



What Is RTV Silicone?

RTV silicone has all of the same characteristics as regular silicone, with a few exceptions. If you’re wondering what the RTV stands for, its an acronym for “room temperature vulcanizing”, which means that (as the name suggests) this silicone undergoes and vulcanizing process at room temperature, effectively making it a type of rubbery substance once this process has been completed. RTV silicone is pretty versatile too, considering that it can be used for a number of things.

Since RTV silicone is sticky when wet, it can be used as an adhesive in order to join two or more surfaces together, or it can be used as a sealer since it becomes quite rubbery once it has had the chance to dry out and cure completely.

As you can see RTV silicone can be used in a number of professions and industries, from construction to crafting, and even production lines. This is one of the many reasons that RTV silicone is so popular, in addition to the fact that this silicone tends to last for a relatively long time and can be found in pretty much any hardware or home improvement store in the US.

RTV Silicone Guide

There are many ways to dispense and use RTV silicone, and as a result, manufacturers have designed different application devices that you can use to apply the perfect amount of RTV silicone to the surface of your workpiece, in just the right shape. You could think of RTV silicone as a more robust and gelatinous superglue, as it shares a similar level of popularity and versatility.



Types of RTV Silicone

Most people who know about RTV silicone don’t know that there are actually two types available. Like some other heavy-duty adhesive substances, RTV silicone is available in a single-part version and a two-part version, both of which are equally as effective.

Single-part silicone tends to cost a bit more because it’s a bit more convenient to use, but it’s no better than its two-part counterpart.

Here are some things to keep in mind about the single-part and two-part RTV silicone variants.


One-Part RTV Silicone

Single-part RTV silicone works pretty much the same way that regular crazy glue does. One-part RTV dries and cures using the moisture available in its immediate environment. Humidity causes the silicone to harden, and the higher the temperature of the immediate environment the faster the silicone will dry out, a neat trick to remember if you ever find yourself in a hurry.

RTV Silicone Emergency Repair

Even though it’s only in one part, this type of silicone still functions exactly the same as the two-part variant, featuring a hard vulcanized rubber texture when dried, being wet and gelatinous when wet, and being able to act as both an adhesive and a sealer.

Single-part RTV silicone is best used for time-sensitive projects and or as an emergency repair tool.


Two-Part RTV Silicone

Two-part RTV silicone is effectively the same as one-part RTV silicone, with the only real difference being that while one-part RTV uses moisture in the air to catalyze, two-part RTV uses moisture in its second part to do so.

Once the two parts are combined in the ration instructed by the manufacturer they will cure and eventually vulcanize into the same durable silicone as the one-part version.

Two-part RTV sometimes makes use of additives to make the reaction and adhesion more consistent or increase the bonds between molecular links. This does depend on what the RTV will be used for, and as you might suspect, these versions of RTV silicone can be a lot more expensive when compared to the run-of-the-mill variety.



Chemical Composition of RTV Silicone

For such a versatile material, RTV silicone has a pretty simple chemical composition. What’s in the stuff then? RTV silicone consists of silicone polymers, organoreactive silane catalysts, and fillers which form a Si-O bond capable of having many variations attached to the primary structure. This is part of what makes RTV silicone so versatile and easy to use.

This is also what allows it to be a room-temperature vulcanizing material thanks to the way it reacts with ambient humidity in its immediate vicinity.

Pretty cool right? The actual component that creates the silicone we all know and love is called dimethyl dichlorosilane, which is the part that reacts with airborne moisture or even liquid water.

Chemistry of RTV Silicone


Physical Properties of RTV Sealant

RTV silicone has the properties of, well, silicone. It’s relatively dense with a gelatinous consistency while wet, which turns into a rubbery consistency once dry.

RTV sealant does not absorb moisture well, in fact, it repels moisture which is what makes this material such a good sealer and adhesive compared to others in its class.

RTV silicone sealant is easy to work with and can easily fit in a number of containers. This is part of the reason that it can either be applied manually or it can be squeezed out of a long tube using a silicone applicator. RTV silicone sealant also has a distinct almost pungent smell that makes it easily identifiable in virtually any environment.


Chemical Properties of RTV Sealant

The chemical properties of RTV sealant are pretty much the same as we mentioned previously. RTV is pretty durable when put up against everyday forces, it isn’t super viscous, doesn’t absorb moisture when dry, and isn’t really reactive with any other chemicals. Again, this makes it the ideal adhesive and sealant.

Characteristics of RTV Silicone

When it comes to putting up with exterior forces like impact, abrasion, tension, and torsion, RTV silicone simply snaps back into place, being decidedly challenging to even leave a mark on. Even forces like heat and extreme cold don’t make much of a difference to this material, and it is capable of dissipating excess heat and simply thawing out naturally if frozen.


Mechanical Properties of RTV Sealant

RTV silicone isn’t very dense or particularly strong, but it is pretty robust and is capable of taking quite a bit of punishment. This is because of its rubberized nature which allows the substance to distribute force quite well, whether it be impact and/or abrasion. RTV sealant has a number of other properties that make it sought after as well.

RTV sealant has a decent shore hardness, an average tensile strength, isn’t very easy to tear or penetrate, and can be used on a wide variety of materials.

The adhesive qualities of RTV silicone are pretty good too, allowing this type of silicone to hold workpieces of varying materials together indefinitely in some cases.



Applications of RTV Silicone

Now that you know what some of the important properties of RTV silicone are, let’s have a look at some of the many applications you can find silicone being used in today. Because silicone is so versatile and robust, you’d be surprised as to just how many industries and professions make use of this sticky, rubbery substance.


Industrial Settings

RTV silicone is commonplace in industrial settings. It can be used for a number of applications, including the lubrication of machine parts, the gluing together of product components, the adhesion of signage to surfaces, and even as a sealant for machine parts or any other application in which a firm, custom-made seal may be needed.

Industrial RTV Silicone


Construction Settings

While there are many other adhesives available today, silicone is still one of the most commonly used products in the construction industry. What is RTV silicone used for in the construction industry? Well, it can be used to bond materials like metal, glass, wood, ceramic stone, and even composite materials to other surfaces or to each other.

Construction RTV Silicone


Medical Settings

If there were one industry in which silicone was indispensable, it would have to be the medical industry. Silicone isn’t only used to augment one’s physical appearance, it can also be used to aid in absorption and reduce the risk of bacterial infections by being easy to sanitize. Silicone can also be used to create molds and parts of prostheses.

Medical RTV Silicone


Automotive Settings

When automobiles first came about, virtually all the materials used were made of crude, ferrous metals. As time went on lighter materials like aluminum and carbon fiber were introduced, leading to durability and longevity for our vehicles. Silicone is another material that contributes to this by acting as a high-quality sealer, adhesive, and filler for engine mounting points. RTV silicone is an ideal supplemental sealer for installing new gaskets.

Automotive RTV Silicone


Household Settings

It might be challenging to imagine but silicone is all over the modern home. Whether it’s the cutlery in your kitchen drawers, the cups in your cupboards, or the organizers holding your home’s wiring together, the chances are that at least one of them is made of RTV silicone. Many internal components of appliances and things that are in plain sight are made of this material. If your oven is suffering heat loss, you can use RTV silicone to apply a new heat-proof seal on its door.

RTV Silicone Household Uses



Advantages of RTV Silicone

Like any other material on the face of the planet, RTV silicone has some pros and cons associated with it. Let’s have a look at some of the advantages and disadvantages of using RTV silicone so you can establish whether or not this substance is what you would like to use the next time you need something to be adhered to or sealed.



RTV silicone is one of the most versatile adhesives and sealers on the market. It can be used as a building sealer, an industrial adhesive, an engine mount press fitting, to create medical implements, and even to create cutlery.

There are very few substances that are quite as versatile as silicone, aside from epoxy resin and crazy glue.


Resistance to Extreme Temperatures

RTV silicone is well known for its temperature-resistant characteristics. What is the temperature range of RTV silicone you ask? Well, according to certain studies, RTV silicone is able to withstand temperatures in the range of -80 degrees Fahrenheit to 400 degrees Fahrenheit, ensuring that your workpiece and the surface it’s adhered to are safe no matter how extreme the weather.

RTV Silicone for Extreme Conditions


Resistance to Chemicals and UV Light

If you thought the safe temperature range of the RTV silicone was impressive, you’re going to love finding out that not only is it also resistant to the effects of corrosive chemicals but RTV silicone is also resistant to the effects of UV light. This means that it can be easily cleaned, and your workpiece can be left in direct sunlight without you having to worry about damage.


Highly Durable

Aside from being resistant to the effects of chemicals and UV light, RTV silicone is also pretty tough. Being resistant to the effects of impact and abrasion, many materials are coated with RTV silicone to increase their ability to absorb large amounts of force without compromising their structural integrity.

RTV silicon is also really easy to clean when it gets scuffed.


Easy to Apply and Cure

Compared to other adhesives that share some of its characteristics, silicone is very easy to use and it cures quite quickly. Whether you are using the two-part or one-part RTV silicone, all you need to do is follow the instructions which usually only takes a few minutes, and you’re done. Virtually no surface preparation is necessary!

RTV Silicone is Easy to Apply



Disadvantages of RTV Silicone

As we mentioned previously there is no such thing as the perfect material, and RTV silicone is no exception to the rule. With that being said, RTV silicone isn’t perfect for every occasion, so let’s have a look at some instances where you might want to have a look around and see what other adhesives and/or sealers are available to you.


Poor Adhesion to Certain Materials

Even when a pressure-sensitive adhesive is involved it can be difficult for RTV silicone to adhere to certain surfaces. RTV silicone will stick to glass, plastic, wood, metal, and even rubber.

Keep in mind that any material outside of the aforementioned list will have some trouble allowing RTV to adhere to it, at least without some thorough elbow grease and preparation.


Difficult to Remove Once Cured

Another thing that might rub you the wrong way about RTV silicone is the fact that it can be challenging to remove. This shouldn’t be a surprise considering that it’s resistant to impact, abrasion, UV light, heat, moisture, and chemicals. Silicone often needs to be removed by force, so be prepared for a light workout if you ever want to get rid of some.

RTV Silicone is Difficult to Remove


Shouldn’t Be Used for Structural Applications

While RTV silicone can be used in home renovation you should never use it for structural or load-bearing applications. While sealing the underside of countertops or sealing bathroom tiles is all well and good, your RTV silicone simply does not have the tensile and/or adhesive strength for structural and/or load-bearing applications.


Now that you know what RTV silicon is, what it is used for, what different types are available to you, and some of the pros and cons of using this adhesive, why not try some for yourself? Silicone is versatile and inexpensive, which means you can safely experiment with its uses and won’t have to worry about it breaking the bank.




Frequently Asked Questions


What Does RTV Stand For?

Have you ever found yourself wondering about RTV silicone? After all, what does RTV stand for to begin with? RTV stands for room temperature vulcanizing and perfectly encapsulates how this silicone product transforms once it begins to interact with moisture.


Is RTV Silicone Any Good?

RTV silicone is versatile, easy to use, readily available, and inexpensive, and you can pretty much use it on all common surfaces. RTV silicone has many uses, and you’d be hard-pressed to find any industry that doesn’t rely on this material in one way or another.


Is RTV Silicone Food Safe?

Yes! One-part RTV silicone sealant has been approved as food-safe by the FDA when completely dry and cured. This means that this type of silicone can be used to seal food packaging or as a sealer on oven doors without causing harm to the health of consumers.