A Guide To Painting Over Polyurethane Sealants
Polyurethane sealants are the go-to for many renovators and contractors due to the flexibility, durability, compatibility with various materials, and superior mechanical strength of the material it offers. In addition to being waterproof and resistant to shrinkage, polyurethanes are sandable and paintable, making them suitable for a wide range of home improvement and construction applications. As a rule of thumb, oil and latex paints are ideal for this particular type of sealant. This article provides you with a step-by-step guide on painting over polyurethane sealants.
Getting Your Supplies in Order
Before you get that paint out, you will need to gather all the required supplies and tools to make this process a safe and smooth-sailing one. We’d also recommend following the safety guidelines and instructions of the products you are using to ensure that they do not react negatively with each other. To protect yourself and prioritize your safety, work in a well-ventilated area and always have gloves and protective goggles on standby. These are the following tools and supplies we’d recommend preparing before painting:
- Oil-based paints and primer
- Protective face mask
- Mineral spirit/solvent
- Lint-free cloth
- Sanding paper
- Wood filler
Letting The Sealant Cure
You should always let your caulk cure completely before painting over them. As polyurethane sealants do not dry and will chemically cure, they will require moisture to do so. Therefore, if you live in a dry climate, chances are you will have to wait longer than those who live in a more humid environment. Generally, if you are using water-based paint, you will have to wait for at least two days, while if you are using oil-based paint, you will have to wait at least a week.
Preparing The Surface
After letting them cure for a few days, you will need to prepare the surface to remove any dirt, dust, and debris. You can do this by dipping the cloth in a mineral spirit of solvent to clean the area to achieve a cleaner and more even paint finish. If you are working on wooden furniture such as drawers, cupboards, and cabinets, remove all the additional hardware like screws, doorknobs, and fasteners. Next, add in wood filler to cover any prominent gaps and chips. Then, sand the excess polyurethane down and remove the wood dust.
Priming The Surface
To obtain the best possible results, apply a layer of oil-based primer to provide a better surface for the paint to adhere to and prevent any form of stains or wood from showing through the paint. Ideally, you should let it dry overnight before deciding if another coat is necessary. However, if the grain and texture are prominently showing through the primer, you should apply another layer to better cover and smoothen the surface. Once the primer has completely dried, you can prepare your tools and start painting.
Painting The Surface
Start painting the first layer on the surface using your preferred color of oil-based paint. Allow the first coat to dry overnight and paint on a second coat to achieve a more opaque and even finish. Once the furniture and wall surface is fully painted, allow it to air dry for at least three days before adding the hardware as required. Congratulations, you have successfully painted over your polyurethane sealants!