FAQs about Cardboard Boats

Answers to questions we are asked the most

Do people really use cardboard boats?
How are the boats protected from water damage?
Where do I get cardboard to build a boat?
How long will it take me to build a boat?
Can I take my cardboard boat white water rafting on a river or use it in salt water?
When on the water always wear a Coast Guard approved Personal-Flotation-Device (PFD)

Do people really use cardboard boats ?

You bet they do! Annual cardboard boat regattas attract in excess of 100,000 spectators and more than 1,500 participants from around the United States.
Check out some of the many links to cardboard boats on the web.
As of this writing no one has designed an all paper corrugated-cardboard boat that is strong enough, lightweight enough, and fully water resistant to be used over and over again like the boats in The Cardboard Boat Book.
PLEASE NOTE: If you intend to participate in an organized cardboard boat race or sponsored regatta please review the boat design requirements for the event to ensure that you can enter with one of our boats. Our boats typically EXCEED the design specifications for most events.

The construction process includes covering and sealing all exposed seams of cardboard to completely seal the boat from water entering inside the cardboard layers. Once the seams are fully protected, the boat is coated with a rubberized waterproof coating material. When the sealing and coating is done properly the cardboard is protected from water damage.
We have boats that are 23 years old and are still being used!
The recommended waterproof coating is an acrylic elastomeric coating used for waterproofing roofs, concrete, and wooden structures. I have had extremely good results with products from Ames Research in Oregon, USA. I have used both their 'Block and Wall' product and their 'Maximum Stretch' product.
There are numerous products available on the market. Look for 'acrylic elastomeric coatings' when researching your options.
These coatings can be colored with coloring made for acrylic paint. Take your coating to a local paint store and have them color your coating with whatever color you desire.

Many large appliances and large pieces of furniture are shipped in 275# test, 1/4 inch thick, double-wall corrugated cardboard boxes. These boxes can be used to build a boat. Check with your local appliance and furniture outlets for these types of cardboard boxes.
New sheets of 275# test, 1/4 inch thick, double-wall corrugated cardboard can be located on the web by searching for 'cardboard sheets'.
To build one boat you will need 2-1/2 - 48" x 96" sheets, and 2 - 60" x 60" squares or 1 - 60" x 120" sheet.

With two people working together we have cut all of the pieces, constructed all of the components, and assembled a boat in one day, including taping the boat for waterproofing.
Once assembled and taped, the contact cement is allowed to cure overnight. Once the contact cement is cured the boats are coated inside and out with a minimum of three coats of the rubberized waterproofing material. If the coatings are applied in succession, one coat after another leaving time for each coat to fully cure, it is reasonable to expect that you can have a boat ready to place in the water within 7 days from the start of construction.

NO! We highly discourage this activity. Leave this activity for boats that have been specifically built for this.

We HAVE NOT tested the cardboard boats in salt water and therefore do not have any advise on this matter. We recommend that you use your boat in fresh water lakes only.