What the Hull

What the Hull
Magazine View

Spray Foam Magazine – Spring 2021 – As spring fast approaches and more vessels launch into the water, Spray Foam Magazine takes a look at why boat builders are incorporating SPF insulation into their builds. Apart from the obvious use of flotation foam, a type of closed-cell foam, which is a lightweight material that works well as a flotation foam, why else do these ship builders use SPF?

Coastal Craft Yachts are based in Gibsons, on British Columbia’s Sunshine Coast. Many of the Gibsons locals feel at home on the water with generations coming and going from the town’s harbor. Coastal Craft Yachts have been building aluminum boats and yachts in Gibsons, BC since 1996 with vessels ranging in size from 18 feet to 65 feet and being sold throughout North America.

When Coastal Craft Yachts opened in 1996, their efforts focused on crafting reliable and efficient water taxis and crew transport boats for British Columbia’s logging industry with their hand-built aluminum hulls quickly gaining a reputation for strength and structural integrity. They later focused their attention to the pleasure craft market and are now recognized for building yachts and boats that are both beautiful and luxurious with precision and detail. The Coastal Craft Yachts still incorporate the strength, power, and dependability of the aluminum-hulled work boats that they built when they first opened.

Coastal Craft hires Blue Frog Spray Foam, also based in Gibsons, at least once a month to spray foam the hull of their boats. Owner Robert Humphries noted that, “Coastal Craft Yachts expect the best and are extremely good at what they do. They hired Blue Frog Spray Foam to help with condensation control and noise mitigation.” Humphries opened his business in 2012 and has been spraying boat hulls for six years, so is also now an expert in boat spraying.


Coastal Craft’s team of talented local craftspeople have often incorporated SPF into the design of their boats and yachts since their first vessels in 1996. Jeff Rhodes is the President of Coastal Craft Yachts, and he explained the importance of applying SPF, “Over the past 25 years we have learned that properly applied spray foam in the right areas is effective at providing a 

Blue Frog Spray Foam applies closed-cell insulation to Coastal Craft Yachts on the inside of the exterior shell plating, such as hull bottom plates, hull side plates, deck plates, both inside accommodation spaces and mechanical spaces, superstructure (cabin) sides and top.

good source of thermal and acoustical insulation in our aluminum boats.We apply foam to the inside of the exterior shell plating such as hull bottom plates, hull side plates, deck plates, both inside accommodation spaces and mechanical spaces, superstructure (cabin) sides and top. We also apply foam to our bulkheads between accommodation spaces and mechanical spaces.”

On this particular job, the Blue Frog crew used a Graco E30i to spray Genyk two-pound closed-cell foam, which is approved by the Coast Guard standards, installing three quarter inches of a set to the entire hull. Humphries was the main sprayer, and it took him between eight to 10 hours of spray time, including prep and cleanup.


Spray foam has been used in the marine industry for a number of years, most notably for the insulation of aluminum and steel vessels. Closed-cell SPF is often the foam of choice due to the material not easily absorbing water. The depth of the foam applied is really dependent on the design of the vessel and the depths of the hull and underneath the deck. These areas are prone to condensation buildup due to the large surface area and usually the first place a vessel owner will want insulated. SPF can also morph around the shape of the hull with ease and hug to the substrate, filling awkward-to-reach nooks and crannies.

Many marine vessel owners have also recognized that SPF can be applied around working parts of the vessel like the engine, to help prevent damage from condensation and therefore prolong the life of the working parts. SPF also adds a layer of soundproofing to help mask the vibrations and noises which are generated from the working parts of the vessel. In comparison to a structure on land SPF is a great thermal insulator, helping keep the structure cool in summers and warm in the cooler months.



Coastal Craft Yachts in-house production departments include aluminum and stainless-steel fabrication and welding, wood joinery and cabinet making, yacht painting and finishing, mechanical/electrical rigging and installations, service and maintenance, engineering and design and administration. Having production in-house also enables them to encompass their customers’ requests and design details into their boats.

The Coastal Craft team expects the best work and highest quality in everything they produce and therefore hired a certified spray foam professional to ensure their already high standards were constantly met.  

Spray foam morphs around the shape of the hull with ease and hugs to the substrate, filling awkward to reach nooks and crannies.

By: Spray Foam Magazine Staff on Mar 23, 2021
Categories: Thermal / Fire Barrier Coatings
Tags: spray foam magazine, contractor's corner, spring issue 2021
Issue: Spring Issue 2021