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Marine plywood is the go-to material when it comes to boat construction. It is suitable for any water vehicle and makes for great boat construction. It is a more durable, higher-quality product manufactured of Western Larch or Douglas-fir that hasn’t been chemically treated.
The ten best alternatives to marine plywood are:
- Fiberboard (Medium Density Fiberboard)
- Exterior Grade Plywood
- Fiber Cement Board
- Birch Plywood
- Ribbon Grain Plywood
- Wax Resin Fiberboard
- 3M Reinforced Polyurethane Foam Boards
- Thermo-Lite Board
- King StarBoard
- Weather and Boil Proof Plywood (WBP)
I will take you through each alternative I’ve listed above, giving you their pros and cons so that you can make an informed decision when buying supplies for boat construction.
1. Fiberboard (Medium Density Fiberboard)
Fiberboard is one of the best alternatives to marine plywood. It is also called a medium density board (MDF). MDF is a composite wood product usually made by breaking down softwood into wood fibers in a defibrillator.
This is then mixed with wax, using a synthetic resin binder like urea-formaldehyde resins (UF), another suitable bonding system, and creating panels under high temperature and pressure.
Due to its machinability, fine finish, strength, and consistency, fiberboard is also widely used in various home and commercial applications, like furniture, cabinetry, flooring, and even speaker boxes.
Pros
- MDF is hard to flex or crack like natural wood
- MDF is cheaper and easier to find compared to marine plywood
- MDF lacks grain or texture, which makes it easier to paint and seal
Cons
- Engineered wood is easily damaged
- MDF is heavier than solid wood, which means you’ll need more anchors and extra support.
- Engineered wood is made of wax and resin components, making it vulnerable to extreme heat.
- Compared to solid wood, the fiberboard can’t support a lot of weight.
- It is only suitable for interior use.
2. Exterior Grade Plywood
This plywood is designed for exterior use. It is moisture-tolerant and designed to survive harsh environments. It can also be used for internal purposes, although you will need to polish it more to make it visually appealing. Exterior plywood is widely utilized in the building industry because of its structural properties and low cost.
Pros
- Exterior plywood uses cross-graining, which makes it solid and durable.
- It has a high level of dimensional stability, making it ideal for base material construction.
- Exterior grade plywood is easy to procure and is affordable.
- Exterior plywood is eco-friendly since it needs less wood to produce than solid wood.
- Making exterior plywood sheets has a higher embodied energy than other timber products.
Cons
- It is not smooth
- It isn’t free of visual defects
- It needs extra smoothing whenever it’s used in interior applications.
- Compared to solid wood, exterior plywood provides less thermal insulation.
- It has relatively low breathability compared to solid wood.
- Exterior plywood glue has toxic additives such as urea-formaldehyde, which is highly harmful to the environment.
- Exterior plywood has meager fire resistance.
3. Fiber Cement Board
Fiber cement board or siding is a low-maintenance, long-lasting material that is often used to cover the exteriors of homes and, in some cases, commercial structures. It’s made of cellulose fibers, cement, and sand, and it’s exceptionally long and sturdy.
The fiber cement board, like fiberboard, is made of tiny wood fibers. Instead of glue or resin, cement joins the wood fibers together.
Pros
- Fiber cement board is highly durable, so it doesn’t deteriorate or require frequent repainting.
- It’s fireproof, insect-resistant, and works well in the event of a natural disaster.
- Fiber cement board is low-maintenance.
- It is energy-efficient and can help insulate your house.
- Fiber cement board is visually pleasing.
Cons
- FCB is heavier compared to other types of wood.
- It is brittle so it chips easily.
- Fiber cement board is very dusty when cut.
- It costs more to buy and install fiber cement board compared to other types of siding.
4. Birch Plywood
Birch plywood is created from Northern European birch trees of the highest B/BB grade. The plywood trees thrive in cold regions and have very close growth rings, making them highly sturdy and long-lasting.
Birch Plywood is one of the most economical substitutes for marine plywood.
When they are exposed to moisture regularly, the durability of birch plywood deteriorates. As a result, they are well-suited to create boats’ interiors and furniture rather than exterior furnishings. Since birch plywood is both strong and aesthetic, it’s commonly used for shelving, doors, and paneling.
Pros
- Birch plywood is aesthetically appealing because of its smooth, rich appearance.
- Three or more layers of Birch are joined to form a single sheet of plywood, which makes it more durable.
- Besides being a versatile product, birch plywood is also easily accessible and frequently available at low pricing compared to other plywood.
- Birch plywood has very few knots and little to no rough edges, making it safe for building children’s toys and furniture.
- Birch plywood has a low environmental impact because the trees are an abundant and fast-growing species.
Cons
- Birchwood is highly perishable and decays fast when exposed to warm weather.
- Birch plywood is susceptible to bug infestation if not treated well.
- Birch cuts easily with woodworking machinery, but the interlocked patterns moderate blunting on blades.
- Because birch wood is hygroscopic, it can easily deform and break in a dry climate
5. Ribbon Grain Plywood
Ribbon grain plywood is named after its remarkable design because it contains grain patterns that resemble ribbons. If you buy ribbon grain sheets, you’ll notice grain stripes along the length of the wood.
This plywood has an excellent level of sleekness. After installing it, you don’t need to polish and paint it to smoothen its surface further. Since some construction processes are already removed, this saves a lot of time, money, and effort during the construction process.
Ribbon grain plywood is one of the best alternatives to marine plywood because of its robust nature.
Pros
- It is exceptionally smooth, which removes the need to paint and finish during the construction process.
- Ribbon grain plywood is highly durable and doesn’t crack easily.
- Ribbon grain plywood is beautiful.
- It is an economical option for boat construction.
Cons
- Ribbon grain wood is not as strong or durable as marine plywood.
6. Wax Resin Fiberboard
Wax-resin fiberboard is made in a similar way to other types of fiberboard. It is not entirely constructed of wood. Wax-resin is excellent for extra fiberglass strength. So, you’ll need to combine your softwood fibers with wax resin to make a wax-resin fiberboard.
The coupled wood is then sliced into sheets and heated to high pressure. As a result, the wooden sheets are far more durable, solid, and resistant to moisture.
Hydrogen bonding is used in some processes. Hydrogen mixes the softwood fibers as an alternative to resin.
Wax resin fiberboard is an excellent substitute for marine plywood because it is lightweight yet strong and durable.
Pros
- It is suitable for many construction applications, including boat construction.
- It is highly available at low prices.
- It is lightweight and highly durable.
- It’s moisture resistant.
Cons
- It is susceptible to extreme heat damage due to the wax and resin.
7. 3M Reinforced Polyurethane Foam Boards
The 3M Reinforced Polyurethane Foam Board is specialized for boat construction. It is suitable for semi-structural and structural applications.
Fiberglass is useful for strengthening the form boards to make them suitable for marine use (by layering as a sandwich). Compared to traditional plywood, this material offers weight savings ranging from 30% to 60%.
You won’t have to deal with uneven surfaces while working with artificial material.
Foam boards are therefore helpful because they are smooth and level. There is no chipping or warping of the material.
Working with foam boards is easy. It’s simple to install both inside and outside of the boat.
Pros
- It is rot-resistant.
- It is lightweight material making it easy to transport.
- It is available in five densities ranging from 15 to 26 pounds per cubic foot.
- It has no risk of warping.
- Unlike plywood, they don’t chip or pop loose during construction.
Cons
- It contains polyurethane, a hygroscopic substance that absorbs water and disintegrates with time, losing support and quality.
- It is toxic to the environment, especially when burnt.
8. Thermo-Lite Board
These boards include all of the features and benefits that all types of builders are looking for. It is rot-free, light, and sturdy and provides excellent long-term performance.
Thermo-Lite board is ideal for those DIY people looking for the best ways to restore, remodel, or repair their boats, homes, or motorhomes. It is lightweight and can be used for interior design, ceilings, and walls.
Thermo-Lite is made of a non-absorbent material. As a result, it improves the material’s stability, increasing its strength and endurance. It absorbs high impacts well and does not degrade in harsh temperatures.
Thermo-Lite boards may be the correct choice if you need to replace or update your construction material. You can use it to design your motor homes and your boats too.
Pros
- It has a non-absorbent composition which boosts durability and stability.
- It is rot-free.
- It is lightweight and strong, offering a lifelong performance.
Cons
- It has a plastic-like finish that doesn’t look or feel like natural wood.
- If scratched and exposed to water, it starts to degrade.
9. King StarBoard
King StarBoard is industrial-grade plywood made using high-density polyethylene. It is cheaper than marine plywood and very efficient, making it an excellent alternative for construction projects. It results from a patented production method known as K-Stran, the most advanced manufacturing procedure for improved flatness and uniformity.
King StarBoard has a matte gloss finish on both sides of the sheet. As a result, there’s no need to polish or laminate the material after installation.
The material is extremely durable and resistant to discoloration. It also doesn’t rot, and its lamination doesn’t peel off with use so this marine plywood alternative will save you time, money, and effort.
Pros
- King StarBoard is highly affordable.
- It is strong and doesn’t discolor with time.
- It is rot-resistant.
- Its lamination doesn’t peel off, saving time and money used to laminate again.
- No need to polish after installation.
Cons
- It is plastic material and will not give you the wood finish if that is what you are seeking.
- The material can sag when exposed to high temperatures.
- It can bend if it’s not supported properly.
- You can’t paint it.
- It is challenging to glue.
10. Weather and Boil Proof Plywood (WBP)
Weather and Boil Proof plywood is one of the most durable plywood. It uses melamine or phenolic resin as glue. The best WBP plywood should be made with phenolic glue. WBP plywood is best designed for exterior use in house buildings, food, shelter, and concrete shuttering.
WBP plywood is glued using high-quality melamine adhesive. As a result, it effectively combats high temperatures. The sheets can withstand up to 20 hours in boiling water.
Pros
- It is perfect for applications with long-term exposure to water and moisture.
- It is more affordable than marine plywood.
- It is waterproof.
- It is lightweight.
- It is crack-free and knot-free.
Cons
- Due to the extra benefits, it is costly compared to most types of plywood.
Frequently Asked Questions
Some of the commonly asked questions about cheap alternatives to marine plywood include:
Can I Use Regular Plywood, Do I Really Need Marine Plywood?
Depending on the intended use, regular plywood may serve you well. However, when using plywood to make boats, especially parts submerged in water, we recommend you go for marine plywood.
Regular plywood has only three layers, while marine plywood has five or more layers joined with a waterproof adhesive to support greater loads and keep moisture out of the core. This makes it more durable and stronger than regular plywood.
Can I Make Plywood Waterproof?
You can spray liquid latex or clear-colored polyurethane varnish on your regular plywood to make it waterproof. You can also coat it with epoxy sealant or hard-drying oil to seal it and make it impervious to water. The epoxy sealant is the most effective and widely used material for waterproofing plywood sheets.
What Is the Difference Between Marine Plywood and Treated Plywood?
Marine plywood is specially made for marine use because of its assembled gap and void-free layers. Waterproof glue tightly holds the layers together making it water-resistant. On the other hand, treated plywood is regular plywood that has been pressure-treated with chemicals. The pressure treatment prevents the wood from decaying and rotting but doesn’t make it waterproof.
Sources
- The Spruce: What Is Marine-Grade Plywood?
- Wikipedia: Medium-density fibreboard
- Timber Blogger: MDF vs. Plywood: Everything you should know about MDF and plywood
- The Spruce: Fiber Cement Board Siding Basics
- Business Wire: 3M™ Reinforced Polyurethane Foam Offers Lightweight Alternative to Plywood
- Hunker: The Disadvantages of Polyurethane
- homestead: What is WBP Plywood?
- ContractorBhai.com: What is BWP and BWR grade Plywood?
- Wikipedia: Embodied energy
- Your Home: Embodied Energy
- Composite Panel: Medium Density Fiberboard (MDF)