What do you seal RV windows with? (5 types of seals)

In this article, we will answer the following question: What do you seal RV windows with? Learning how to RV seal windows is not difficult and can help you improve the temperature in your home. Here you will find the essential information so you can start sealing and get the most out of your RV windows.

What do you seal RV windows with?

To seal RV windows you will need a good sealant gun and a high-quality sealant. Generally, sealants can be acrylic latex, silicone latex, silicone, or polyurethane.

  • Acrylic sealer is water-based, which means it is easier to clean. Despite not being very resistant to weather or temperature, it is possible to paint over the acrylic sealer or buy it already tinted to complement colour compositions, making it a good option for interior sealing.
  • Silicone sealant is similar to acrylic sealant but contains silane, a characteristic of silicone. It has many of the properties of acrylic sealant, but has greater resistance to weathering and creates a more durable adhesion. This makes silicone a very good option for exterior window sealing.

Silicone sealant is very resistant to temperatures and can have high resistance to mould, making it a great option for use in the kitchen and bathroom, and in ventilation and air conditioning appliances. The silicone sealant can be neutral or acetic. 

  • Acetic or acidic silicone works very well for non-porous materials like glass. Neutral silicone works great with wood, metal, or plastic, as well as materials like vinyl siding. Silicone is very resistant to water, which makes it work well with pipes and sinks.
  • Polyurethane sealant has a different reactive base, so it has other properties. It can be a bit more complex to work with than a silicone sealant. Polyurethane sealants work very well for fixing most household materials but can deteriorate over time when exposed to UV radiation.
  • Silane modified polymers are excellent adhesives for use on most substrates, combining the properties of silicone and polyurethane. For a strong and elastic bond to clear window frames to the wall and to be resistant to weather, pollution, UV radiation and dust, use an elastic sealant such as Pattex SP101. 

It is a Flextec polymer with a high immediate grip, with excellent elastic recovery. Remember that it is always better to carry out a previous application to check the adhesion with the surface on which you are going to work.

Sealing RV windows is an important step in keeping your motorhome well-insulated and energy-efficient. Sealing the windows will prevent air leaks and protect yourself from humidity, significantly reducing the use of heating or air conditioning to heat or cool your RV. 

Having the right tools to seal your RV windows is a very important step. A good sealant gun is essential in any home repair kit. Sealing guns can be found at any hardware store and are used to apply the sealing cartridges.

 Look for one with a smooth stem and a good drip system that has a spring-loaded mechanism for easy pressure application. This avoids the excess of sealant and ensures a homogeneous and consistent seal in its application.

How to fix a broken RV window seal?

Window sealing rubbers tend to break or leak at their contact points, where one section meets another: where the windows meet the frame, or where the frame meets the wall.

Start by scraping off any old sealant or old coating agent. Use a sealant remover if necessary. If applying silicone remover, let it sit for a few hours. Once the sealer has softened, remove it with a specialized tool or putty knife.

 Clean surface debris as much as possible to apply the new coat and achieve a strong adhesion. Otherwise, the seal may not be as effective. Be aware that some sealer removers require specific chemical treatments to remove residue. Consult the product instructions if you have any questions.

You may have to put up the window. Spread it over the base of the window to create a more compact seal. Paint what you consider necessary and let it dry following the instructions on the product.

Apply the new sealer once the work area is clean and dry. Load the sealant cartridge into the gun and open the tube. If you need a versatile sealer for many types of surfaces and that also has great adhesion, is resistant to weather and with a powerful sealing force.

Apply the sealer to the surface with constant pressure in one motion. Use a wet finger or a damp cloth to spread the sealer well. You can use masking tape before applying the sealer to trace the path you will take with the gun, in addition to protecting the areas where you do not want the sealer.

Once applied, allow the seal to sit dry for 24 hours. After this time, your window should be hermetically sealed.

A tip when setting your windows: if you are not sure where the air is seeping into your window, put a lit candle around the frame. If you see the flame move, you’ve found the leak!

How to seal an RV broken window frame

To seal a window frame you will need to follow the same steps that you used to secure your window, but it requires a little more care to make sure your window is still in excellent condition.

For an interior window frame, use an acrylic sealer. Pattex Cracks and Fissures is a quality acrylic sealer for increased durability and adhesion. Sets quickly, but it is recommended to wait 24 hours before painting over. 

It is a perfect sealer for gaps between frames, sills and trim. And it provides superior adhesion on wood, concrete, cement, plaster, plaster, brick, tiles, stone, and porous materials in general. For its application in other types of materials, it is recommended to test before in another area to verify the setting.

How to seal RV window frames and sills

To seal RV exterior frames and sills, you will need a product that will withstand harsh weather conditions. Your best option is the SL650 from Pattex, as it permanently seals with great resistance to weather and water in most spaces and exterior joints. 

It is durable, flexible, and resistant to UV radiation. It is ideal for sealing windows and for surfaces such as concrete, porous substrates in general, glass, anodized or lacquered aluminium, iron, steel, methacrylate and rigid PVC.

FAQ on What do you seal RV windows with?

What is used to seal windows?

To properly seal the window, it is convenient to make a silicone bead (preferably neutral and the same colour as the carpentry) both at the junction of the window frame with the wall, and at the union of the frame with the glass (at least, in the outer face, in contact with the street)

How to clean window seals?

To clean window seals, prepare in a small basin hot water mixed with white vinegar (70% water and 30% vinegar). Use a sponge, soak in this solution and rub the joints until the stains disappear! Then rinse with clean water and dry the whole with a clean cloth.

How to renovate a rubber seal?

To maintain the seals of your car, we recommend that you use WD-40 Specialist Silicone Lubricant. Its formula does not attract dirt and provides insulation against moisture. It is compatible with rubber, so it is perfect for car gaskets!


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