MJM’s Market-Leading C5® Composite Construction Process

An MJM is so efficient that it can plane at 12 knots

MJM Yachts’ high-tech structural composites lead the industry. High-strength lightweight composites allow a narrower and higher-performance waterplane. As you
accelerate, the bow never rises. An MJM rises on its deep V for smooth and level acceleration. The fore and aft trim is always level, so the progressive deep V works correctly through a seaway.

The bow of a heavier boat rises when trying to accelerate on a plane and needs to reach 20-24 knots before planning occurs, and then the bow can come back down.
Heavier boats have difficulty running between 10-24 knots. Their bows are up, and their bellies are exposed to pounding waves.

An MJM rides comfortably and nimbly through this speed range, which is critical in rough conditions.

Half The Weight, Twice the strength

When the composites were studied under a microscope, the former process showed the E-glass adhered to the tops of each bead of the foam core surface. The C5® process enveloped each foam core bead completely and bonded to the entire foam core surface, forming adhesive and mechanical bonds between the E-glass skins and the structural foam core. MJM’s C5® Process is a leap in technology vs the earlier wet-preg process. Compared to typical production powerboats, MJM’s C5® process typically delivers half the weight and twice the strength.

Innovation & Continuous Improvement

Given the same composite materials, independent testing confirmed that MJM’s C5® process led to 25% more strength and 15% less weight over more traditional materials and processes.

To innovate, improve, and lead, MJM set up its dedicated high-tech composites factory to apply the latest clean and closed aerospace composite techniques. MJM enlisted some of the brightest minds to develop a new process to lead the yacht market in lightweight, high-strength composites.

A five-year multi-million-dollar investment in development yielded our next-generation composite process.

MJM’s C5® Process is applied to the hulls, structural grids, decks, arches, lids, and pilothouse roofs.

The C5 Process delivers:

Lower Center Of Gravity
~ More stability, less motion, and greater safety.

Lighter Weight
~ A narrower water plane for less motion through a seaway
~ Level acceleration and no bow rise
~ Planing begins at 12 knots. In the roughest seas, choose your comfortable speed, always with a level ride
~ Superior speed and fuel economy from less horsepower

Greater Strength
~ A quieter, tighter, and more solid feel is reassuring in a rough seaway
~ Heirloom quality construction to pass down through generations
~ Enhanced impact resistance
~ Engineered to withstand the elements

What is MJM’s C5® Process?

C5® = Closed Compressed Clean Oven-Cured Composite. MJM’s C5® Process is an aerospace composite technique applied to yachting.
A description of the process:

DRY STACKING COMPOSITES
Precision table-cut E-glass and CNC-cut structural foam composite layers are dry-stacked in the mold without epoxy. E-glass overlaps and fiber orientation are positioned strictly for engineered performance. The structural foam is tightly fit and free of gaps.

HIGH-TECH MEMBRANE
A high-tech membrane covers the dry stack to allow air and gases out and resin in. After the epoxy hardens, it is removed.

CLOSED PROCESS
An impervious sealing layer makes C5® a closed vacuum process devoid of air.

COMPRESSION OF THE DRY STACK
High-capacity pumps vacuum the air from the closed process to 20 millibars. The atmosphere is at 1000 millibars, so the dry stack of E-glass and foam core is compressed by 2000 lbs per square foot of atmosphere. The woven E-glass compresses to half its volume, reducing the epoxy volume by half.

EPOXY MIXING
MJM’s custom-developed epoxy resin formulation is precisely mixed by machine for the vacuum infusion process.

CLOSED VACUUM EPOXY INFUSION
The epoxy is drawn into the compressed dry stack vacuum, combining the composite layers into one bonded structural unit, akin to an I-beam. No fumes, odors, or volatile organic compounds are emitted into the environment. The epoxy is contained within the closed vacuum process, which achieves a 30% resin to 70% E-glass ratio, on par with the highest-performance aerospace composite processes.

CONVECTION OVEN FOR POST CURING
The hull, structural grid, deck, and pilothouse roof are post-cured at 185F degrees for 8 hours in MJM’s custom-built high-tech 20’ x 60’ convection oven. Sixteen thermocouples measure and log the composite temperatures across the part to ensure an even post-curing cycle. Why is post-curing beneficial? The heat transforms the epoxy by cross-linking the polymers, leading to a 30% increase in part strength—just from cooking! No other production boat builder delivers the sophistication, data, and controls of MJM’s high-tech post-curing process. The custom convection oven and its computer controls are unprecedented.

The Luxury Of Comfort
Ride comfort is the goal. Regardless of sea conditions, MJMs can enjoy any day on the water with a smooth, soft ride. The MJM C5 Process provides a lower center of gravity for less motion. The narrower waterplane allows the hull to knife through seas. The spray chines redirect the water’s energy outward and downward to dampen roll in a seaway. An MJM does not endure the slamming and pounding that jolts families on wider, heavier yachts. The smoother ride minimizes fatigue, allowing a longer running day.

Efficient Performance Delivering More with Less
Less weight, a narrower waterplane, and low-speed planing reduce the need for horsepower. An MJM delivers more fuel efficiency and speed with less horsepower. The key differentiator is our C5® Process, which is half the weight and twice the strength. High-tech composites make MJM a unique high-performance yacht. You can go further and stay out longer. Spend more time out there and less time at the fuel dock!

The Carolina-Downeast Design Vision
The MJM C5® Process makes key MJM differences possible: fast and fuel efficient, a solid and smooth ride, with comfort and safety in any condition. When you take the wheel of an MJM,you will instantly feel the difference. An MJM accelerates and handles like a sports car. Your family will enjoy the ride; you will enjoy the responsive handling.