There are two methods to waterproof MDF. You can opt for using manufactured Moisture Resistant MDF, which is a little more expensive than standard MDF. Or you can paint your MDF with moisture-resistant wood sealant or varnish.
MDF can be waterproofed by adding a high-quality wood sealant, varnish or stain, or moisture-resistant paint so that your project can withstand threats of moisture and humidity. Do not use waterborne polyurethane, as it may not hold on to the MDF's surface.
Moisture resistant MDF, also known as MR MDF, contains a resin that is moisture-repellent, making it the perfect wood alternative if you're worried about humidity. This makes MR MDF the perfect option for bathrooms or kitchens, known for its durability and strength, it can handle rooms known for their humidity.
Shellac or water-based polyurethane would both work. Both can be brushed on. Water-based poly is easy to use and easy to clean up.
Moisture-resistant MDF does provide a better quality finish and the finished product will maintain its shape and appearance over time. The HDFWR MDF has a smooth surface which is easy to work with, it can be painted or laminated to give the desired look.
WaterProof MDF boards that called as HDF generally come in Green Colours woods. USE: This Product Use for modular kitchen, home & office furniture, wall panelling, ceiling solution. It can be finished using veneers, laminates or paint.
MDF is comparatively weaker than wood, and, therefore, has a shorter lifespan compared to wood. MDF sheets can crack or split under extreme stress. MDF absorbs water more quickly than wood. MDF contains VOC (volatile organic compounds), containing urea formaldehyde, that can cause irritation to the lungs and eyes.
MDF is not waterproof, but it is moisture-resistant if it is properly sealed. Plywood is moisture-resistant, but it is not waterproof.
If the MDF will be taking heavy-traffic and may be prone to scuffs, it is a good idea to preserve the finish using a final sealing finish such as Sadolin Extra Durable Clearcoat. This is optional, especially if you do not want to add an extra level of sheen to the MDF, which a gloss polyurethane can leave.
Moisture Resistant MDF, MRMDF or Moisture Resistant Medium Density Fibreboard, is a durable and versatile material that is specifically designed to withstand moisture and humidity.
Your MDF furniture should not be placed directly on wet surfaces, during the rainy season. Separate the furniture from the wet surface with placemats or other protective barriers.
Thickness sizes: 6, 9, 12, 15, 18 mm (1/4", 3/8", 1/2", 5/8", 3/4"). Width sizes: 122 cm (4'), 183 cm (6'). Length sizes: 244 cm (8'), 366 cm (12'). Standard sizes : 122x244 cm (4'x8'), 183x366 cm (6'x12').
The features associated with water-resistant MDF make it suitable for different environments such as bathrooms and kitchens where moisture content is at an all-time high. It also applied in general joinery, laundry and utility rooms, washrooms, boiler rooms, and cubicles in commercial structures.
Making MDF water-resistant
What you need is a high-quality wood varnish, sealant, or stain – Barrettine treatment is a great option as it is a wood sealer for rough, sawn, or smooth timber. It also comes in a range of colours, so you can make the MDF look more attractive while adding a layer of waterproof protection.
No, you should never use Medite MDF outside, unless the panel is explicitly for outdoor use. If you need to use MDF outdoors, choose either Medite Exterior or Medite Tricoya Extreme.
You can also create waterproof MDF by adding a high quality wood sealant, varnish or stain or moisture-resistant paint so that your project can withstand threats of moisture and humidity. Do not use waterborne polyurethane, as it may not bind readily to the MDF's surface.
Skipping the MDF sealing step – Unsealed MDF absorbs paint unevenly.
It's critical to choose a paint that can be sprayed and is appropriate for MDF. Polyurethane (PU) paint, for instance, is a popular choice due to its durability and resistance to wear and tear.
Glued-together materials made of wood, such as chipboard, MDF, and laminates, are not eaten by termites. However, they might go through these components en route to the "good stuff," like your built-in framework and timber infrastructure. Chemically treating and sealing them, however, can stop this.
Here's what you should know:
MDF and moisture do not get along. If not sealed in a humid environment, it will warp and swell. Most MDF contains urea-formaldehyde, a suspected carcinogen, and other Volatile Organic Chemicals (VOCs).
The material is often bound together with a urea formaldehyde resin, although formaldehyde-free boards are now also available. Despite rumours to the contrary MDF has not been banned in the USA (or anywhere else), nor is it likely to be.
HDF (High Density Fibreboard) is an engineered wood product made from compressed wood fibres, resin, and wax. It has a higher density and is harder than MDF. HDF is commonly used for flooring, cabinetry, furniture, and other applications where durability and strength are required.
Compared to real wood MDF will have a shorter lifespan, with around 14 to 20 years the standard.