Diving into Our First Batch of Surfboard Coupons at UCSD!
Hello Composites Community! Sascha here, along with Matt. This week, we're thrilled to delve into the specifics of our first batch of surfboard coupons. Let's break it down:
1. Dimensions: The Blueprint
Our coupons are designed to mirror a standard surfboard. They measure 24” x 6” x 2.5”, with the thickness aligning with typical surfboard dimensions. On both the top and bottom layers of the coupon, we apply 4oz E-Glass. Additionally, the top layer receives an extra 6oz E-Glass reinforcement. This consistency ensures our research remains as authentic and applicable as possible.
2. The Theory: Why Multiple Coupons?
In our research, the use of multiple coupons isn't just about quantity—it's about depth and precision. By producing a range of coupons, we're able to create an envelope of expected structural properties for a standard surfboard. This multitude allows us to derive various statistical metrics, offering a more comprehensive understanding of surfboard behavior. When we introduce a new surfboard design, we can compare it to the average surfboard's properties, providing a more meaningful comparison than juxtaposing two individual coupons. This approach accounts for the inherent variations in materials, the fabrication process, and testing conditions, ensuring our analysis is both thorough and accurate.
3. The Layup Process: Crafting the Coupons
Fabricating these coupons is both an art and a science. We start with sheets of EPS foam, each ¾ inch thick, and laminate them together using an EPS spray adhesive. Once laminated, we shape the foam block with a hot wire foam cutter. But that's not all! We then bisect the foam cores and integrate a balsa wood stringer right in the center. The final touch? Laminating the coupons with E-Glass. The top layer even gets an additional reinforcement, mirroring traditional surfboard construction. We use epoxy as our resin of choice and employ a vacuum bagging procedure to ensure uniformity in our coupons.
We're excited to share this journey with all of you and look forward to your feedback and insights. Stay tuned for more updates from our end! For a visual treat, check out the pictures below that detail a few of the 16 coupons we produced, all representing the general surfboard design.
EPS Foam Layup on the Hot Wire Cutter
4oz E-Glass Preparation Process
EPS Foam Core with Balsa Wood Strings
Vacuum Bagged Coupons After Wet Layup
Final Production Coupons