Cal Poly Students Design & Build Adaptive Paddleboard from Urethane Foam

Cal Poly San Luis Obispo requires a Senior Capstone Project that is the culmination of a student’s undergrad education.  Each year groups of 3 to 4 students pick a “real world” project sponsored by industry or the community and devote three quarters to the design, build and testing of their project.  One such group took on a “Paddle Board for all Persons” project for the Central California Adaptive Sports Center (CCASC) based at Shaver Lake, California with Professor Sarah Harding as their Advisor.  

For their project the four mechanical engineering students, Alexander Holthaus, Garrett Holmes, Garett Jones and Sean Yuch, not only built a highly adaptable outrigger pontoon system for a standard paddleboard, they also created a collapsible ramp that can be used from a beach or dock.  Volunteer Composites Consultant George Leone fills us in on this senior student project, designed using Precision Board urethane tooling foam from Coastal Enterprises.

In George’s own words…

Stand-up Paddleboarding (SUP) is a popular watersport activity, but current SUP technology is limited for persons with various disabilities.  While there are currently adaptive paddleboards on the market, they are often limited to only certain types of disabilities, feature parts that are fixed onto the board, and are priced beyond what most adaptive sports nonprofits can afford.

The student’s challenge was to design a system that could attach to any commercial stand-up paddleboard and make it extremely stable so that people with a variety of disabilities could safely use it. The system also needed to be assembled with a minimum of tools, disassembled quickly, and be easily portable.  Finally, it needed to be made of commonly available materials since the design needed to be “open source” to allow more wheelchair users to enjoy stand-up paddleboarding.


A primary design focus of the project is to make it usable by a large number of people with different disabilities and levels of mobility.   Another factor was that the system had to support a person or persons with a combined weight of over 350 pounds since an instructor often needed to be onboard with the participant.  Further, the harness system needed to accommodate a wide variety of wheel chairs so that participants could use their own chair.

The result was an adaptive SUP system that can be adjusted and modified for each user. Instead of drilling holes into the board and bolting a chair (limiting its usage and buoyancy), the students created a Velcro strap system that can connect any wheelchair to an aluminum support frame attached to a standard commercial SUP.  They also created two adjustable outrigger pontoons that connect to the SUP for stability and buoyancy.  Finally, the students also created a collapsible ramp so a wheelchair user can roll onto the SUP in their own wheelchair and be secured down with the help of another person.


Coastal Enterprises’ Precision Board High Density Urethane PBLT-6 density foam was chosen for its consistent density and flexibility for both hand and machine shaping.   The added benefit of the foam’s versatility with all resin systems during the manufacturing process was also a plus. Finally, the availability of educational on-line videos covering everything from basic shaping to gluing pieces together was definitely important to the team!

The foam needed to be light and strong not only as a final product, but also because it had to be moved many times during the build process.  Its high ‘Rapidly Renewable Resource’ content of 23.9{afbea94bd31582343c3017644f03ec8d7d8fa2386ecb82c250661e06c0c6e111} was also a factor in the Team’s decision to use Precision Board foam, and it resonated well with project sponsor Randy Coffman, Executive Director of CCASC.


After the design phase was complete, the students moved to the construction phase.  Since they knew nothing about fiberglassing, they enlisted my help (Ed note: George Leone is the recently retired Student Projects Lab Supervisor and long-time surfboard maker).  I welcomed the students and talked them through the foam shaping and fiberglassing elements of their project.

The components of the paddleboard were built in two of the shops in the Engineering College. The Mustang’ 60 shop in the Bonderson Projects Center and the Hangar Student Projects shop. A real airplane hangar. There used to be an airport on campus and a hangar big enough for a DC-3 (15,000 sq. ft.) was built in 1947.

The Team used an older ShopBot CNC router to shape the foam sheets to fit together internally, while leaving a “rough shape” on the exterior to save machine time. Since time on the university’s ShopBot is in high demand, the Team opted to do the final shaping by hand.

After they bonded the layers of foam into a single piece for each pontoon, they left the top open so they could glass the hollowed out interior using polyester resin, thus saving weight and strengthening the pontoons.  Once they bonded the top foam “cap” on each pontoon, the exterior was hand-shaped to the final contours, using “cereal-box edge” templates and bending long strips of metal to blend the larger curves.  Finally, the exterior was glassed with polyester resin.

In the testing phase they measured the buoyancy to find the height where the outrigger pontoons sat in the water. They marked the height and punched holes through the pontoons above that line,  inserted .25″ (6mm) wall 2.5″ (65mm) aluminum tubing,  then bonded the tubing to the pontoon with micro-balloons and epoxy, wrapped carbon tow around the tubing and over the top of the pontoons to reinforce the general area.

These pontoons slide on a pair of 10 ft. (3m) 2″ (50 mm) diameter aluminum tubes that bisect the SUP through the aluminum support frame. This allows the pontoons to be moved to a wider or narrower stance depending on the weight and skill level of the user.

On June 8, 2019, the Adaptive Paddleboard was tested in Morro Bay, CA and passed with flying colors.  Ten days later, on June 18,  2019, a 26 year-old woman who has spastic quadriplegia (a severe from of cerebral palsy) set out on Shaver Lake to experience a watersport that she never dreamed possible.  Here’s some photos from the CCASC Facebook Page of that day.

George Leone ran the Cal Poly Projects Shop from 2001 to 2017.  This shop includes facilities for machining, student welding, woodworking, sheet metal work, advanced composites and design space for senior projects, as well as nine engineering clubs that compete at a national level.  After retiring in July of 2017, he signed up as a volunteer again working with student teams and Senior Projects at least 1 day a week.

The College of Engineering at Cal Poly San Luis Obispo is an internationally-recognized, premier undergraduate engineering college. Its mission is to provide an excellent Learn by Doing education and to graduate in-demand, Day One-ready professionals. The College vision is to transform students into world class, innovative and collaborative engineers to meet the challenges of the 21st century.

State-of-the-art facilities and laboratories form the core of Engineering’s project-centered curriculum. Ranging from the Aircraft Design Lab to the Rotor Dynamics Laboratory, these facilities offer advanced technological systems that allow students to link theory with practice. College buildings also promote interdisciplinary project activities, including the Advanced Technology Laboratories, Bonderson Projects Center, and Engineering IV. With 19,000 square feet of space for individual and team-based projects, the Bonderson Center offers enriched opportunities for multidisciplinary projects and collaboration with industry. Engineering IV, a 104,000-square-foot building includes modern classrooms and laboratories for aerospace, mechanical, civil, environmental, industrial and manufacturing engineering programs.

At Coastal Enterprises, we like to look at the composites industry as a fully collaborative effort. Every fresh new development by an individual is really a contribution to a collective knowledge base. Like any scientific pursuit, the most potent advancements are made when information is shared freely between likeminded groups of people. For this reason, we feel obliged to do everything we can to enlighten and empower the future community of composites professionals.  That’s why we support school programs with donations of Precision Board HDU.  Click HERE to find out more about the program or give us a call with your questions at 800-845-0745.

Looking Back and Moving Forward: 2015 in Review


Cal Poly SLO Supermileage Car

As we reach the culmination of another whirlwind year here at Coastal Enterprises, it’s important not to let the holidays pass us by without taking some time for reflection. In the fast-moving world of composites, it’s too easy to move right on to the next task without meditating on the events that brought us to where we are today. Quantifying our successes, our failures, and our formative experiences from the past months is an essential part of the learning process, and allows us to better focus our efforts for the next year. It’s been a big year for the composites industry in general, and we have seen advancements in 2015 that will truly shape the face of the modern world. From the successful launch and recovery of SpaceX’s Falcon 9 rocket, to the continuing development of Boeing’s highly advanced 777X twin-engine jet, the foundations are being laid for incredible leaps and bounds in technology in the coming years. We are proud to be part of a community that is actively working toward the betterment of human kind as a whole.

Chico State University Concrete Canoe Team

The most important factor in our own growing business are the customers that believe in us, who trust our products and service enough to continue standing by us as we move forward. No matter how good our material is, we wouldn’t get anywhere without people willing to take the plunge and try it for themselves. So as the year finally comes to a close, we would like to take this opportunity to say thank you. As hard as we work to improve and perfect Precision Board, it is our customers that make it all possible. Thank you for trusting us to provide the best customer service in the business, and the ideal HDU substrate for your industrial and signage needs. We are so thankful for each and every one of you, and we are ready to start this New Year the same way we did last year: with personal, comprehensive service; dedicated to helping you get the most out of Precision Board. We wish you a merry Christmas, happy holidays, and a joyous New Year. See you in 2016!

Cal Poly SLO ASME Team

2015 was a huge year for creation, invention, and innovation. Check out some of the incredible projects accomplished by our customers this past year!

InterSign Group


Impressive Signs and Graphics

Sawatzky’s Imagination Corporation

Xpressive Graphix

What’s the Life of your Sign?

We all know Mark Roberts at InterSign Group is an avid Precision Board user, but he also works with other materials. In the June issue of Sign Builder Illustrated, he wrote an article on the process of restoring redwood signs (p16). The great thing about Precision Board HDU is that it doesn’t require the maintenance of wood and has an indefinite life span. Since it’s completely inert and doesn’t absorb moisture, it won’t crack or warp.  Precision Board also has a Life of the Sign Warranty so how can you go wrong?

You can see read the article using the link below:

Share your story, let us know how Precision Board compares to other materials you work with. Email your stories to, you could be featured in our next blog!

Request your free sample today, by simply clicking here!

For more information call us at 800-845-0745 and our friendly Technical Department will be happy to assist you.


Remember, with Precision Board Plus Creativity has NO Limits!

Our CNC Machine Finally Arrived…

Xpressive graphiX has created another stunning sign and has been chosen to be “Today’s Guest Blogger.” Tony Rose, Business Partner & Creative Director, with Xpressive graphiX writes the following

Lock 9 Pizza a new business located in Duncan Falls, Ohio, came to us because they had seen several signs of ours around town. In particular, The Olde Falls Inn, that was featured on Coastal Enterprises blog a few years ago and was a winner in the Signs of the Times Magazine 2014 contest last year.

Up until this sign, all of our 3D projects had been hand made, and only certain parts were outsourced to be machined. We finally built up enough 3D business to have a Multicam 1000 CNC installed, and this sign is the very first project we machined with it. In fact, to meet the deadline, we jumped in with both feet and started machining the parts for this sign the first day our machine was installed! Nothing like the rush of throwing a $400 sheet of material onto a machine we had never used!

Typically we hand carve Precision Board Plus which gives us a 3-4 week turnaround time. But, thanks to our new CNC, it only took 7-days (without working overtime)!  What a drastic difference it has made!

It worked flawlessly, considering I had never used Multicam or EnRoute Software before this project. I quickly understood the basics of EnRoute and by following the steps on Dan Sawatzy’s Blog I also learned other 3D techniques.


This sign measures 12” x 4’ x 8’ and is made from 2” PBLT-18 to get that awesome 3D look. We then glued SIX different sizes and shaped layers onto a steel internal frame using PB Bond 240 adhesive and finished it off with locally sourced PPG exterior latex paints and glazes, which we mixed ourselves.


We have been using Precision Board Plus for the past 3 years and love how easy it is to work with. For this project in particular, we were blown away on how effortlessly it machined along with the quality of the results and the effects Precision Board can achieve.

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Most importantly our customer was very impressed with the detail and quality of the sign! She loved the results so much that additional Precision Board signs were requested, instead of the traditional aluminum and vinyl for their parking and directional signs.

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Request your free sample today, by simply clicking here!

Or for more information call us at 800-845-0745 and one of our Sales Reps will be happy to assist you.


Precision Board Spring/Easter Challenge

Spring is here! Easter is approaching (Congratulations East-Coast you made it!) and we’re challenging you to show off your best Spring/Easter themed display designed from Precision Board Plus.

Top 3 winners will be given a FREE Companion Product Sampler Package.

Post your creations to Facebook or Twitter using #easterwithprecisionboard

Winners will be announced Friday, April 10th 2015 at 11:00 AM PST.

How about some life-sized Jelly Beans in your Easter-basket this year!

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Artist, sculptor and film director Cosimo Cavallaro created these delicious Jellybeans in.        You can read more about his creation here.