Epoxy Curing For Building Boats and Other Water Craft

Boat Building Epoxy

To many people, summer means time on the lake or in the ocean boating or jet skiing. Have you ever considered how boats and other water craft are built? High-tech water vessels of today use some form of fiber construction and boat building epoxy.

boat building epoxy

Epoxy Construction on Water Vessels

Unless you’re out enjoying the water in an older, traditional wooden or aluminum boat, you are likely sitting in a piece of modern engineering–the type that involves high-quality plastics, glass fibers (sometimes referred to as glass-reinforced plastics – aka: fiberglass), and on some occasion, even carbon fiber. Today, most boat and jet ski construction uses composite materials, and this also requires heavy-duty resins.

Boat Building Composites

High-grade epoxy resins bind composites, such as fiberglass and carbon fiber. These resins both bind and coat the material in a hard, nearly impervious shell—making for very strong construction. For those familiar with epoxy curing, it is apparent that the primary challenge is temperature. Most epoxies cure well above room temperature, and when the construction project is as big as boats, the endeavor becomes all the more difficult.

Gold Coast Yachts and Improved Epoxy Curing

Gold Coast Yachts manufactures high-end, carbon-fiber watercraft.  In June 2014 President Richard A. Difede grew increasingly concerned about the cost and time it took for their post-curing of large carbon-fiber joints on the yachts. The epoxy joints needed to cure at 145° F for an extended period of time, and the procedure Gold Coast used took too much time and money.

Building an Oven

Gold Coast had to design, build, and utilize large custom ovens for each section of yacht frame that needed high-temperature exposure. In other words, they were building a large shed around each and every frame. Workers used two-by-fours and sheet rock and created a sealed unit to pump heat into. The process took a good deal of time and manpower, not to mention the extra costs for equipment.

Building the makeshift oven was only half the battle. Once they completed building the unit, someone had to man the oven for the duration of the cure to regulate the temperature. To prevent a compromised process and time delays, they could not allow the temperature to fall below 145° F or climb too high above it.

Even while pumping the constructed oven with ample heat, they were still having trouble penetrating through all the layers of carbon fiber. If the right amount of heat didn’t penetrate through all layers, the cure wouldn’t set completely.  This long, costly, and inefficient process began to eat into the company’s valuable time. 

Powerblanket and Boat Building Epoxy Curing

“When Richard contacted us, it was obvious that he needed something far less-expensive and time consuming than his present method,” the Powerblanket sales rep said. “I discussed with him the details of our epoxy-curing blankets, and he was excited to try them out. What started with a two-foot-by-two-foot test blanket quickly snowballed into many more orders.”

Difede and his team soon found that the Powerblanket curing solution worked exceptionally well and eliminated the need for the time consuming prebuilt ovens.  With a thermostatic controller on each blanket, they could dial in the ideal temperature and have confidence the process would run smoothly. Powerblanket’s patented technology distributed heat evenly through the entire application and increased the speed of the cure by leaps and bounds.

After trying out the small demo blanket, Difede and his team purchased several additional blankets in multiple sizes. It wasn’t long before they decided to take it one step further. After learning about Powerblanket custom heating solutions and the ability to manufacture custom blankets for just about any application, Difede purchased several custom-sized blankets for current and future projects.

Curing at Ideal Temperatures

Powerblanket offers the boat-manufacturing world a much better solution. With Powerblanket epoxy and resin curing blankets, a manufacturer can saves thousands of dollars and hours of time just on one boat build. Our curing blankets allow epoxy to cure at its ideal temperature for as long as needed. What’s more, Powerblanket curing blankets are available in ready-to-ship and customizable sizes and shapes.

Epoxy Specifically Developed for Boat Building & Boat Repair

West System offers two-part (resin and hardener) epoxy systems developed for use in boat building and boat repair. These products are formulated to provide maximum physical properties with ease of use and versatility. With the 105 System, users can blend resins, hardeners, fillers and additives to get the right combination for their project’s requirements. 105 Resin pairs with one of four hardeners based upon the user’s needs for working time and coating clarity. Adjust the mixtures handling and cured physical properties with fillers and additives. This product allows users customize the epoxy to their exact needs for boat construction and boat repair.


Cure your epoxy resins faster and easier than ever before with Powerblanket.

Resin Curing Temperature

Resin curing + heat. This is something that isn’t discussed too much because, let’s be honest, it’s not a great selling point. The quicker and easier you can get your epoxy to cure the better, right? Resin curing temperature and curing time will vary depending on the mixture and manufacturer. While some systems are designed to ‘cure’ at room temperature, heat must be added for epoxies to reach optimal performance properties. Heat can be added via composite curing ovens, radiant heat, or epoxy curing blankets.

aircraft epoxy resin curing

Types of Epoxy Resin Systems

There are probably several ways to categorize resin systems, but we’ll be focusing on two:

  1. One-part systems vs. two part systems
  2. Systems that cure at room temperature vs. those that require heat.

One-part systems vs. two part systems

While some systems are one part, most resin mixtures require two components. In one-part systems, heat is required to “kick-start” and maintain the curing process. More specifically, temperatures must be maintained around 250°F-350°F for a few hours (specific requirements vary).

Two part systems require the following elements: resin and a curing agent. Mixing the two initiates the chemical reactions necessary for curing.

Resin Curing Temperature: Room Temperature vs. Added Heat

As we’ve briefly touched on, heat requirements for epoxy curing vary from system to system. Quite often, all that’s required of two-part systems is mixing the resin and curing agent; the epoxy or composite is them able to finish curing at room temperature. However, some systems require additional heat. Again, the specific requirements of each system vary and can be obtained from the manufacturer.

Powerblanket Epoxy Curing Blankets allow for even and consistent heat distribution to ensure optimal epoxy curing and performance properties. The blankets are mobile solutions that eliminate the need for expensive composite curing ovens.

Why Add Heat?

epoxy resin curing

Knowing that room-temperature curing is an option, you might ask yourself, “Why would I want to go to the effort of adding heat during curing?” The key phrase here is “trade-off”. Adding heat usually means additional equipment and planning. However, epoxy mixtures that require heat boast the following properties:

  • Chemical resistance
  • Electrical insulation
  • Heat resistance

Hotter is Better!

It’s important to note that all epoxy mixtures (even those that ‘cure’ at room temperature) will technically not fully cure unless heat is added. Properly adding heat to systems designed to cure at room temperature will always boost the performance of the final product. However, curing at room temperature makes more sense when increased performance isn’t needed.

resin curing

Let’s take a quick look at what this looks like in practice. Specifically, let’s look at how adding heat can increase the temperature resistance of a room-temperature cured system. Temperature resistance is measured by Glass Transition Temperature (Tg). Let’s say we have a room-temperature cured composite with a Tg of 100°C (212°F). When the composite is kept at 150°C (302°F), the Tg will increase by approximately 10-15°C (5-8°F). Keeping the product at the temperature for an additional 4 hours will increase the Tg by roughly an additional 5-8°C (1-4°F)


Many manufacturers use heat in a “post-cure” to achieve desired properties. This typically follows two simple steps:

    1. The epoxy is first left to cure at room temperature overnight. This allows the mixture to “gel” before heat is added. When heat is added to early, it can affect the viscosity. Drops in viscosity can cause the mixture to “run” and can lead to uneven texture in the final product.
    2. Heat is applied for a few hours. A good rule of thumb is to keep temperatures 50-100°C above the Tg of the epoxy. This “post-cure” boosts the epoxy’s performance without disrupting the texture or consistency.



Heat: What Are Your Options?

There are a few effective options for adding heat during the epoxy curing process. Knowing the pros and cons of each can help you determine which is best for your needs. 1

1. Curing Ovens

Composite curing ovens are a highly effective option that allow for precise and even temperature control. Additionally, ovens come in a variety of sizes; whatever needs to be cured, there’s an oven that can fit it. However, this option can be expensive to install and cannot be scaled up or down. Additionally, lack of mobility means projects must be transported to ovens for curing. 

2. Radiant Heaters

Radiant heaters are a more versatile and mobile option. They are notably less expensive than composite curing ovens and can be scaled up or down depending on the size of the project. Unfortunately, radiant heaters can cause uneven curing which leads to discoloration, bubbles, and brittle patches.

3. Heating Blankets

Heating blankets provide all the mobility and scalability of radiant heaters with significantly more precise and even temperature control. Unlike ovens, composite curing blankets allow the heat to be brought to the project (vs. transporting the project to a curing oven). This can save significant time and headache. For example, when repairs are done on wind turbine blades, rather than disassembling the turbine and transporting the blade to a curing oven, repairs can be done on the spot.


Powerblanket Epoxy Curing Blankets

Powerblanket Epoxy Curing Blankets utilize top-of-the-line heating technology to ensure even heat distribution throughout the curing process. Additionally, Powerblanket offers custom options; whatever your curing needs, we can help you develop a solution.

Cure your epoxy resin faster and easier than ever before with Powerblanket.

Say goodbye to uneven curing and subpar epoxy performance.

Check Out Powerblanket Curing Blankets


Alex Pacanowsky

Meet Alex, one of our experts in freeze protection and the head of the custom team at Powerblanket! For the past several years, Alex has worked closely with oil & gas pros, medical device startups, and pharmaceutical suppliers (just to name a few) to create weatherproof operations. No matter how cold the weather, or what needs to be heated, Alex knows just what to do! He also loves mountain biking and spending time with his two boys, 5 and 9, and two Labrador Retrievers.

Powerblanket Hot Box and Curing Blankets for Post Curing

When it comes to post curing, maintaining ideal temperature is a must. And if you’re post curing small to medium sized parts, then you may find yourself using expensive ovens, or else taking a whole lot of time and money to build your own. Thankfully, you don’t need to do either of these with the Powerblanket Hot Box on hand.

Post Curing: Bring the Heat

Post curing is a process during mold making that consists of increasing heat to a mold after the initial curing phase. Doing so allows the mold to cure faster, as well as enhances the physical properties of the mold. During post curing, heat must be evenly transferred to the mold at a constant rate as to not interrupt the natural curing process and cause irreversible damage. These damages can cost time in redoing the mold and in money for having to use extra materials.

The best way to heat molds during the post curing phase is to use an insulated hot box. Hot boxes provide regular, even heating to materials that require protection from low or fluctuating temperatures.

The Powerblanket Hot Box

Powerblanket’s Hot Box (sometimes referred to as a Bulk Material Warmer) works great at maintaining the needed temperature for post curing small to medium sized parts. These insulated heating boxes provide an even spread of warmth to give the mold the exact increase of temperature desired.

The Hot Box’s durable construction allows for secure and lasting installation, while its ease of setup makes it transportable and storable. The Powerblanket Hot Box can be easily assembled, disassembled, and reassembled. It gives you the option of bringing your parts to the Hot Box or bringing the Hot Box to your parts. Our Hot Boxes hold product at a temperature of up to 120° F, and the optional adjustable thermostatic controllers allow temperatures to be controlled with precision.
So if you need to keep your epoxy cures at temperature for prolonged periods of time, a Powerblanket Hot Box just might be the thing for you.


Powerblanket Hot Box pallet warmerOur Premium Hot Box (HB64PRO-1440) Offers:

  • A larger footprint (48” x 48”)
  • An internal steel frame (48” internal height)
  • The highest wattage (1440 Watts)
  • A controller for precise temperature regulation


heated curing blankets
Post Curing with Powerblanket Curing Blankets

Of course, after talking about the Hot Box, you may be thinking, “Yeah, but what if what I need to cure is bigger than 48” x 48?” Well, there are two simple answers to this question. Depending on your application needs, we could build a custom size Hot Box for you. But if one of our resin curing blankets would work better, we would certainly suggest this as an option.

A Blanket for Every Business

If you have curing needs that go well beyond what our Hot Boxes can handle, in regard to size and temperature, then our curing blankets are the ideal answer. Our high-temp flat blankets have high watt densities and produce higher temperatures for post curing epoxies and resins that require ranges beyond 100° F – 120° F, up to 400°F.  What’s more, these blankets can be made to cover large areas simply and effectively.

If you need it heated, Powerblanket has a solution for it. Whether it’s carbon fiber construction, wind blade repair, floor coatings, or some other resin post curing application, Powerblanket has all the options you need to consider paired with a team of world renowned engineers to ensure your project specifications are met. For more information, call 801.506.0198 or visit [email protected].


The Powerblanket Hot Box is the perfect solution for your bulk material heating needs.


Shelby Thompson

Shelby Thompson is the head of standard product sales for Powerblanket. He has a distinguished military career, having served in both Afghanistan and Iraq. In his time in the Marines, Shelby acquired an impressive skillset that he now uses in his current role. When he's not working, Shelby loves spending time outdoors with his wife, son, and daughter. He is also a semi-keen hunter, fair weather fisherman, and shooter. Unfortunately, Shelby also has something of an unlucky streak when it comes to Fantasy Football at the company.