Acrylic sealants are the best type of sealants to paint over.
What do you look for when deciding on a paintable sealant?
Acrylic sealants are the obvious answer when it comes to picking out sealants for surfaces that have to be painted over. They consist mainly of water and acrylic polymers and are more elastic than silicone sealants.
Acrylic sealant is also known as decorator’s caulk or painter’s caulk. It adheres well to most building materials and is paintable. It is commonly used to seal joints and sometimes as a filler.
What is the difference between acrylic and silicone sealants?
BOSTIK manufactures a wide range of sealants using different technologies so that its customers can select the sealing products best suited to their specific projects.
For example, acrylic sealants are paintable and suitable for use both indoors and outdoors (provided a suitable high-quality paint is selected). Acrylic sealants are simple, easy to use, clean, and easily smoothed. And of all the sealant technologies, acrylic is the most environmentally friendly.
A major comparative advantage of silicone, hybrid, and polyurethane sealants is that they can handle greater differential movements between elements. Whereas an acrylic sealant can cope with 12.5% movement, silicone, hybrid, and PU can withstand 25% movement, that is, they can take twice as much differential movement.
Therefore, factors such as temperature range, joint dimensions, and substrate materials will have a significant influence on the selection of the most appropriate sealant type.
For example, acrylic sealants would be ideal for joints in a temperature-controlled indoor environment with no sunlight, and silicone would be a wise selection to seal joints on the exterior of a building where large differential movements are predicted, such as a joint between an aluminium window frame and brick wall surround that will be exposed to direct sunlight.
Acrylic sealants are typically used to seal joints in internal decorated spaces, and they are usually painted over.
If acrylic is the most appropriate sealant type for your proposed use, then you can select the best acrylic sealant to suit your requirements. Bostikis the brand you can rely on for high-quality acrylic sealants and fillers.
These Bostik products are perfect for sealing and filling jobs. They can be painted over and then forgotten about.
- A975 PREMIUM PAINTABLE is a high-quality acrylic sealant that is paintable with most water-based and synthetic paints. It is designed to minimise craze cracking and discoloration of paint that is applied over it. It can be used indoors or outdoors.
- A980 INSTANTLY PAINTABLE is a high-quality acrylic sealant that can be painted over immediately after application. It is used for sealing and filling connection joints, seams, holes, and cracks.
- A930 EASY FILLER PRO is a non-shrinking, ready-to-use, ultra-lightweight, ready-mixed filler and spackling compound. It is made for use in interior environments for filling and repairing cracks and holes in walls and ceilings.
Work with the best. High-quality sealants and fillers that are designed to be painted over.
How to use these products to seal and fill joints before painting?
The following three BOSTIK products are useful for three different scenarios: (1) when you want a high-quality product and time is not of the essence; (2) when you want a high-quality product, but you’re under time pressure; and (3) when you need to fill cracks and holes in walls and ceilings, not just joints.
High quality, interior or exterior.
A975 PREMIUM PAINTABLE
Step 1: Preparation
The temperature of both the environment and the substrates must be within the range of -15 to +35 degrees Celsius. However, we recommend a range of +15 to +25 degrees Celsius.
The temperature of the canister must be within the range of +5 to +30 degrees Celsius. However, we recommend a range of +15 to +25 degrees Celsius.
Before using it, shake the canister vigorously – at least 20 times.
Step 2: Application
Hold the canister with the valve turned upwards and affix the adaptor on the tread. We recommend a universal PU foam gun.
Turn the canister upside down and apply the foam. To regulate the flow of the foam, loosen the valve at the back of the handle. Fill the cavity to 70% of its volume. In a low-humidity environment, lightly spray the foam with water. The foam will expand to fill the rest.
Joints wider or deeper than 4 cm should be filled in multiple layers, waiting 15 to 30 minutes between applications and lightly spraying the foam with water after each application.
Step 3: Painting
Wait for 24 hours for the sealant to fully dry before applying paint. The product can be painted over with water-based and synthetic paints. Note: Before application, test the sealant’s compatibility with the paint you are going to use.
Limitations
- Not suitable for polyethylene, polypropylene, polycarbonate, polymethyl methacrylate (acrylic, Plexiglas, Perspex), Teflon, soft plastics, neoprene and bituminous substrates.
- Not suitable for permanent water load.
- Not suitable if there is insufficient moisture.
High quality, paint immediately.
A980 INSTANTLY PAINTABLE was developed for sealing connection joints that need to be painted over in internal environments. For example, joints between stairs, walls, ceilings, skirtings, window sills, wooden and metal window frames, concrete and brickwork, and/or filling cracks and screw and nail holes in walls and ceilings of wood, plaster, gypsum, brickwork, and concrete.
Step 1: Preparation
- All substrates must be solid, clean, dry, and free of grease and dust.
- Clear all loose particles from the substrate.
- Application temperature +5 to +40°C (environment and substrates).
- Absorbent substrates do not need to be absolutely dry.
Step 2: Application
- Prime very porous substrates such as gypsum, aerated concrete, or limestone with a mixture of 1 part A980 INSTANTLY PAINTABLE and 2 parts water.
- Always test adhesion before application.
- Apply A980 INSTANTLY PAINTABLE per the manufacturer’s instructions.
- Finish and smooth with water.
A joint with the correct dimensions can absorb movements between building materials. The joint depth should always be in the correct relationship to the joint width. This is the general rule: up to a joint width of 10mm, the ratio of joint depth to the width of the joint is 1:1, with a minimum of 5mm in depth. For joints wider than 10mm, the depth is the width divided by 3 plus 6mm.
Step 3: Painting
You do not have to wait for the sealant to fully dry. You can begin painting shortly after applying the A980 INSTANTLY PAINTABLE. The product can be painted over with water-based and synthetic paints. Note: Before application, test the sealant’s compatibility with the paint you are going to use.
Limitations
- Not suitable for continuous exposure to water.
- Not suitable for polyethylene, polypropylene, polycarbonate, polymethyl methacrylate (Perspex, Plexiglas, acrylic), Teflon, soft plastics, neoprene or bituminous substrates.
Fill joints, holes and cracks, interior.
A930 EASY FILLER PRO was developed for filling joints and screw holes in plasterboard walls and ceilings for interior applications. Also for filling, repairing, and smoothing of holes and cracks in concrete, plaster, brickwork, and stucco layers.
Step 1: Preparation
- All substrates must be solid, clean, dry, and free of grease and dust.
- Clear all loose particles from the substrate.
- Application temperature +5 to +40°C (environment and substrates).
- Absorbent substrates do not need to be absolutely dry.
Step 2: Application
- Prime very porous substrates such as gypsum, aerated concrete, or limestone with a mixture of 1 part A930 EASY FILLER PRO and 2 parts water.
- Always test adhesion before application.
- Apply A930 EASY FILLER PRO per the manufacturer’s instructions.
- For best results, apply the product without pressure.
- Finish and smooth with water.
Step 3: Painting
A930 EASY FILLER PRO is paintable when fully dry. (During curing, the product will undergo minimal shrinkage, which can cause paint cracking.) The product can be painted over with water-based and synthetic paints. Note: painting with highly water-based paints can create cracking. Before application, test the sealant’s compatibility with the paint you will use.
Limitations
- Not suitable for continuous exposure to water.
- Not suitable for polyethylene, polypropylene, polycarbonate, polymethyl methacrylate (Perspex, Plexiglas, acrylic), Teflon, soft plastics, neoprene or bituminous substrates.
A reminder of what benefits you get when you use the right BOSTIK sealants and paint over them.
Use these products in suitable conditions, and follow BOSTIK’s recommendations. If you do that, you will help to ensure the long-term performance of the paint applied over them.
A975 PREMIUM PAINTABLE:
- Sustainable, low VOC, and phthalate-free
- Easy to apply and clean
- Perfect adhesion without the use of primer on most, even slightly damp substrates
- Perfectly paintable with water-based and synthetic paints
- Reduces craze cracking and discoloration of the paint
A980 INSTANTLY PAINTABLE:
- Suitable for BREEAM applications
- Almost odourless
- Perfect adhesion without the use of primer on most, even slightly damp substrates
- Paintable shortly after application, with water-based and synthetic paints
- No discoloration of the paint, and minimal risk of craze cracking
A930 EASY FILLER PRO:
- Ultra-lightweight
- Almost non-shrinking
- Easy to apply
- Sandable after curing
- Perfectly paintable with water-based and synthetic paints
For peace of mind regarding the long-term performance of paint over sealants or fillers, insist on using A975 PREMIUM PAINTABLE, A980 INSTANTLY PAINTABLE, or A930 EASY FILLER PRO.
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