Coosa Board is high-density polyurethane foam with reinforced layers of fiberglass. It is truly the premier decking & transom material in the marine industry. There is a reason boat builders put "Certified Coosa Board" decals on their transom! » Read More
It's a no-rot composite sheet material primarily used for coring and decking applications. It’s composed of high-density polyurethane foam reinforced with layers of woven roving and continuous strand fiberglass. It’s structurally superior, doesn’t absorb water, and weighs 30-40% less than marine plywood.
Advantages of Coosa Board
30%-40% lighter than plywood
No water rot or insect infestation
Less than 1% water absorption
Mold, mildew & algae resistant
No special maintenance required
Sanded for easy lamination
Easily fabricated with standard woodworking tools
Coosa board being used to replace the transom in a 1978 Alumacraft bass boat.
Limitations of Coosa Board
Coosa is ideal as a coring material but does have a few limitations. It’s not UV stabilized and will discolor if exposed to direct sunlight; it won’t deteriorate structurally but will become chalky and washed out. Read More
Additionally, it contains fiberglass which can be rough on bare skin. Therefore, we recommend covering or coating in virtually all applications. Some popular ways to cover Coosa are glassing over it, carpeting, or coating it with latex or enamel-based paints.
Finally, due to its foam composition, Coosa Board has less screw retention than plywood and should be thru-bolted or secured using special fasteners like stainless steel t-nuts.
What Are Popular Uses?
Coosa is great for structural applications such as:
With 11 CNC Routers and a design team at the ready, all you need is to send a drawing with dimensions or template for your project to Boat Outfitters and let us take the lead. If you’re more of a do-it-yourselfer Coosa composite board is easy to work with using common woodworking tools and can be ordered in third, half, and full sheets.
Our full sheet size is 48” x 96” which is large enough for most projects. If your project is bigger than 96”, like an oversized transom, don’t worry - we can use a puzzle joint to connect two panels for your exact size needs.
Contact Us
If you’re having trouble finding the exact part you're looking for, the best first step is to take a picture and give us a call.
Our customer service team is here Mon-Fri 8am - 5pm and would love to help you track down the exact hardware you need.
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Commonly Asked Questions About Coosa
When replacing plywood decking, what thickness should I use? (show/hide)
A good rule of thumb is “same thickness, installed the same way”. Bluewater 26 Coosa Board can be used as an exact replacement for any plywood decking as long as the thickness and installation are the same (i.e. if your plywood was glassed over, so should your Coosa).
Install the Coosa panel as you would plywood or the material being replaced. We suggest not changing the lamination structure and method used by the original equipment manufacturer on your particular project when replacing plywood with a Coosa panel - install the panel as you would plywood or the material being replaced.
Do I have to encapsulate the Coosa in fiberglass and resin? (show/hide)
No, as would typically be the case with plywood, to prevent water absorption - Does add stiffness and strength. However, if the OEM encapsulated the plywood you’re replacing for structural reasons, you’ll want to do the same.
What types of resins are compatible with Coosa? (show/hide)
Most marine-grade resins work well with Coosa including epoxy, vinyl-ester, and polyester resins.
What thickness and sizes are available? (show/hide)
We offer thicknesses from 1/2 inch up to 1 ½ inch - panels can be laminated together if your project needs thicker material. Boat Outfitters provides Coosa in full sheets (48” x 96”) half sheets (48” x 48”), and third sheets (48” x 31.5”).
Coosa is easy to cut using standard woodworking tools. If you have a larger project, Carbide-tipped cutting tools are recommended as the material can be tough on blades.
No, Coosa Board cannot be bent. It is very rigid and not very flexible, so if you try to bend it you may damage the panels.
Can Coosa Board be shaved down or shaped? (show/hide)
No, it is not recommended to shave down or shape the panels. If you try to shave down Coosa Board you can cut through the woven roving weakening it structurally.
