“Quality of Manufacturing” – Part 3 of the Best Center Console Make or Break Features

Part 3 of this article series: “Best Center Console – Make or Break Features”, we will be addressing Quality of Manufacturing which is another key aspect in building the ultimate center console vessel. As we previously discussed how imperative the engineering factors play in this process, the temptation exists to cut expenses in the attempt to become more profitable. This mentality is simply a futile mistake that will cost you much more in the long run when it comes to reputation, longevity and value of your boat.

At Bahama Boat Works, cutting corners in manufacturing quality is simply not an option. With that being said, here are some very important things to look for or ask your boat manufacturer when contemplating the boat for you.

Fiberglass Components

   In the fiber reinforced composites (FRP) manufacturing world, the highest standard of construction is termed “advanced composites”.  This is the standard that the aerospace & medical industries have to follow. It is generally accepted within the FRP world that, to qualify for this category, the fabricator has to meet the following criteria:

1.) The fiber to resin matrix ratio should be over 50%

2.) The air entrapped in the composite should be under 1% in volume

3.) Strict quality control must be maintained to insure steps one & two

   Unfortunately, these standards of construction are rarely followed in the boating industry.  In hand applied fabrication, it is much easier for the laminators if they simply flood the fiberglass fabric with resin in order to work out any trapped air, leaving behind excess or even pooled resin.  As a result, the fiber to resin ratio drops far below 50%, with the strength & durability of the panel involved suffering in the process.  Lack of careful attention by the workers can also leave air voids in the laminate, with similar results.  In vacuum infused construction, in spite of employing lower viscosity resins with inherently weaker physical properties than higher viscosity hand lay-up varieties, dry areas in the laminate can result which can severely compromise the strength of the structure.  Bahama Boat Works does not follow or allow any of these practices.  It employs only careful hand lamination techniques using higher viscosity/high physical strength resins, which allow the close inspection of every layer, and insists that its lamination department adhere as closely as possible to “advanced composites” standards.  This insistence is guaranteed by tight quality control supervision and inspection.  Sub-standard components are never accepted, and are rejected rather than applied to the vessel’s construction.

FRP Sandwich Core Hull Production FRP Core Boat Hull Production   Of course, even the most tightly controlled manufacturing protocols will not compensate for the use of poor quality of materials in fabrication.  Bahama Boat Works employs in all of its FRP structures materials that exceed industry standards.  There is not a great deal of variability in the quality of the various fiberglass fabrics utilized in boat construction, but the menu of resins available is quite extensive. In order to understand why the resin component of the composite is so important to the quality of a boat hull, a brief explanation of polyester resin technology is required.  The physical characteristics & qualities of the polyester family of resins vary considerably.  In the marine industry, three types of polyester resins are most commonly used:

1.) Orthophthalic:  Generically known as “boat resin”, this is the least expensive resin in the polyester family.  It has also been around the longest.  Many chemical improvements have been made over the years.  Although it is commonly assumed that all polyester resins are “water proof”, in reality they are not.  Orthophthalic resins display hydroscopic behavior.  That is to say that they can slowly absorb water.  One result of this tendency that has plagued the FRP boat industry is hull blistering. 

Bahama Boat Works does not use ANY orthophthalic resins in ANY of their components, above or below the water line!

2.) Isophthalic:  Though more expensive, this type of resin displays much better physical characteristics than orthophthalics.  Not only are they physically stronger, but they also have much higher corrosive resistance and much lower water absorption than orthophthalic resins.  Some isophthalic resins actually have FDA approval for the storage of potable fluids.

Bahama Boat Works uses premium Aropol 7121 T-15 isophthalic resin exclusively in above deck components.

3.) Vinylesters:  This family of resins are chemical hybrids of epoxy and polyester resins.  They are the most expensive members of the polyester family, but they have the highest physical strengths as well as the highest corrosive resistance.  For example, vinylester resins are the EPA standard for the underground storage of E-10 gasoline!  They are absolutely waterproof!  All hulls produced by Bahama Boat Works are fabricated using ONLY premium AME 6000 vinylester resin – not just in the outside skins of the hulls like most high-end boat manufacturers, but throughout the entire laminate schedule!  This practice is very rare in the industry.  Both types of resins used in Bahama Boat Works products also display excellent secondary bonding performance, and all structural bonding of components is performed with vinylester adhesives.  These are critically important features in hull quality and durability rarely seen in the industry.  Not only are hulls produced this way as strong and durable as possible, but they are also impervious to hull blistering when stored in the water.  It is counter-intuitive, but the wettest portion of a boat hull is actually the bilge – not the outside that is in direct contact with fluid water.  The reason why is the fact that the bilge is constantly exposed to water vapor, which has a much smaller molecular structure than water fluid.  Smaller molecules allow easier passage through semipermeable membranes. The use of only vinylester resin in a boat hull guarantees that moisture in any form cannot enter the laminate from any direction at any time in its life span!

     There is one other factor pertaining to resins that is worth a second mention:  That is the viscosity of the resin employed.  When resins are produced with lower viscosities, such as those intended for infusion,  they tend to automatically display lower physical strengths.  While the “vacuum infusion” of boat hulls can be an attractive manufacturing technique when it comes to efficiency of production, a simple comparison between the physical strengths listed on the “technical data sheets” of infusion resins and non-infusion resins will tell the true story.

Sandwich FRP Core Hull
Sandwich FRP Cored Hull

     In order to build the highest strength to weight structures possible, Bahama Boat Works also employs “sandwich cored construction” on its transoms, hull sides, decks, hatches, consoles, hardtops and other vessel components.  This type of construction results in panels that for engineering purposes are two dimensional I-beams; much stiffer, stronger and lighter than single-skinned panels.  Hull sides feature Corecell foam, which is a semi-rigid/semi-elastomeric product that has a “memory”.  In other words, hard blows do not permanently crush the core.  The result is a sandwich panel that is much more durable during impacts over its lifetime than a rigid cored product.  Corecell absorbs more energy than other core and is much more resistant to being permanently deformed. All Bahama Boat Works, hulls also feature transoms cored with 30 pounds per square inch density Coosa board, which is a high density foam with fiberglass fabric infused in it.  The result is transoms that are lighter than those that are wooden cored, with higher crush characteristics than wood units, but without the potential for rot.

Best Center Console Boat Assembly Practices

The mounting of three or four outboard engines of any size or make presents no structural challenge whatsoever on a Bahama Boat Works hull!

Let’s Talk Hardware

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Bahama Boat Works Quality shines with Hardware

   Bahama Boat Works incorporates only the highest quality of hardware available on their vessels, some of which are custom made for their applications.  Out of the thousands of individual mechanical components carefully chosen & utilized, several stand out:

1.  Fully mortised console door locks:  Bahama Boat Works is unique in its class for its use of proper built-in door locks.  Normally, only yacht builders go through this much trouble to secure a door!

2.  Compression latches are used on all hatches to prevent rattling.

3.  All hardware possible, such as latches, hinges, fuel fills, hawser rings, cleats, rod holders, etc. are blind fastened with studs from the back to prevent corrosion in exposed screw heads.

4.  All tubing on hardtops is heavy-duty, schedule 80 aluminum for long-term durability.

5.  Wiring harnesses are neatly organized & fabricated to military specifications.

   Due to the complexity of Bahama Boat Works’ product line, the hardware list goes on and on, but the theme is really quite simple:  Use the very best components available, no matter how much extra difficulty it might pose.  This applies to every single item used in construction.  At Bahama Boat Works, quality is our first purpose!

Engineering Factors for Best Center Console Boats – (Part 2)

3d_hull

As part 2 of this article series, we will be addressing certain engineering factors that are extremely critical in the manufacturing process of these larger “super-center-console” boats, and why?

One of the first and foremost considerations is the structural integrity of the hull design itself. There are many methods used in the marine industry, but not all of these produce a well-designed hull that will not only ride smooth and dry, but support these increased LOA boats upwards of 40 feet in length, yet maintaining a reasonable weight to size ratio that does not require additional expense in powering a boat that is too heavy, or so light that it reduces the overall ride and comfort and still maximizes deck space. 

The strength and structural integrity of stringers, bulk heads and the integration of the liner and cap can also mean the difference between unnecessary vibrations and stress cracking in critical locations over time that can be costly to repair and reduce the value of the boat in a short period of time.

Then you have the balance concerns, especially when it comes to console, power generation and gas tank placement and installation methods.

Let’s address these engineering factors so you as the customer are educated as to what questions to ask and what to look for in your next super center console boat.

True-Molded Hulls:

   Fiber Reinforced Polymer (FRP) composite boats have been in production for over 70 years.  During that time period, much information has been collected on the best engineering and fabrication practices to follow.  As the hull sizes for center console boats have increased in recent years, proper engineering has become ever more important.  Bahama Boat Works has employed the lessons learned by the industry to manufacture the most structurally sound and durable center console vessels possible with current technology.

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Center Console Manufacturing Hand Laid Chop Strand Mat process

FRP Characteristics:  It is extremely important to acknowledge that fiber reinforced polymer composites are non-isotropic in nature.  That is to say that they do not display the same physical characteristics in all directions like metals do.  Instead, they are inherently highly directional.  While the resin matrix used will behave in an isotropic manner, the fiber reinforcements that are held in column by the cured resin will distribute stress in a linear fashion – kind of like how spokes on a bicycle wheel work. “Load paths” can be accurately defined and positioned.  When FRP composites are simply considered to be isotropic, the considerable potential benefits provided by the reinforcing fibers will most likely not be enjoyed.

Integrated Structure:  The advent of monocoque construction techniques revolutionized both the aircraft and automobile industries.  The term monocoque means that the skins of a structure assume all or most of the loads that might be applied.  For example, in the automobile industry, “unibody construction” yielded stiffer, lighter, more durable and safer structures than the older “body on frame” techniques.  Load energies could be more widely distributed.  Structural strength is defined by the amount of applied energy that can be distributed over the largest area possible.  When a structure is “integrated”, the increase in area produces a great benefit in strength, if for no other reason than the increased surface area.  When equal consideration is given to both the shapes of a structure and the load paths provided by the materials used to fabricate it, a synergy is produced that can yield a highly durable result.

The Bahama 41 hull is engineered with these factors in mind; to provide the most elegant solution possible for an unusually safe and durable vessel.  The construction technique and the painful attention to every detail, although quite technical, is as follows:

1.  Using Bahama Boat Works’ True Molded technique, after being gel-coated and skinned with vinylester resin and all hand laid chopped strand mat applied, all hulls are vacuumed to their mold for the entire three week, 24 hour per day period of their construction.  While other boat companies will remove a partially finished hull from its mold in order to make room for the next order in their production cycle, Bahama Boat Works resists this temptation in order to produce a hull with the highest fidelity to its original CAD/CAM model.  All internal structure has been completed and cured before the interior liner is applied; then the liner is ALSO vacuumed into place.  Only after both hull and liner are fully cured is the hull vacuum on the hull mold released and the completely integrated structure removed from its mold.  It’s not the fastest process, but it is absolutely the BEST process!

2.  After initial skinning with hand laid chopped strand mat, hull bottoms receive two layers of biaxial fiberglass in their spray strakes before special purpose-engineered elastomeric putty is used to fill them.  This allows the following bottom laminations – six alternating layers of 0-90 & 45-0-45 biax on the sides and nine alternating layers in the center – to provide straight load paths across the bottom.  From the chines upward, the topsides feature three layers of 1 ½ oz. hand laid chopped strand mat, 1708 biax, 1” Corecell foam vacuumed in place and 3610 quadrax fiberglass fabric.

3.  All five stringers employed in the hull are solid fiberglass laminates, produced by four layers of 3610 quadrax in a vinylester resin matrix.  This fabrication technique produces stringer reinforcement that does not produce hard points in the bottom when they are applied, thus eliminating the “hinge effect” of glassing non-flexible frames to the craft’s bottom.

4.  Next, all structurally built interior wells are bonded in place to the bottom of the hull with a special flexibilized vinylester putty, and then fiberglass taped in place. This integration process not only assists the stringer system in linear strength, but also provides no less than nine bulkheads to resist hull twisting.

5.  The transom structure features six alternating 0-90 & 45-0-45 biax laminates, 1 ½” 30 pound Coosa and six more alternating biax laminates – with two additional “knees” outboard of the full-length stringers.

6.  Heavy duty 1/4” aluminum fuel tanks, zinc chromate treated for maximum anti-corrosion protection, contoured fabrication designed to maximize fuel capacity and utilization of below deck compartments, and then are thru-bolted, foamed in and fiberglassed in place, then both tank compartments are sealed with fiberglass laminate.

7.  When all internal structure is applied and cured, the prefabricated interior liner is vacuum bonded in place to the stringers and wells using specialized adhesive putties, integrating the finished deck and topsides with the rest of the hull structure.

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Center Console Hull Vacuum Bonding

8.  The hull is finally removed from its mold when all curing processes have finished, and is now moved into the rigging phase.

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Center Console Bahama 41 hull removal from mould.

The 65 plus years of combined marine and boat building experience of owners; Bob Sparks, Scott Henley and Rob Thomson of Bahama Boat Works, share the same passion and commitment of one paramount goal that is never overlooked and kept front and center throughout the entire engineering and manufacturing process.

“To make the absolute finest center console boat by setting a standard unequalled in the marine industry.” The result is a reputation that precedes itself and continues to satisfy every owner with many, many years of sustained value and performance.

See what they have to say (click here).

Contributing Authors to this series: Scott Henley, Bob Sparks, Zed Bennet, Brian Pandiscio

 

Best Center Console Boats – Make or Break features (Series Intro)

Due to the ever increasing popularity of the center console boat, configurations, sizes, features, deck layouts, and a dizzying array of options constantly growing, their widespread popularity is primarily due to the open, unobstructed deck space made available by the design.  When intuitively approached, the resulting layout can yield full walk-around fishing room, easy access to the water, and uninterrupted 360 degree visibility for the captain and crew.

build

Whether you are a casual family cruiser, a scuba diving enthusiast, or a hardcore fisherman, the center console boat can answer all of your needs. As consumer demand has resulted in the size of the vessels growing, it is no surprise that the new category of “Super Center Consoles” has been established in the market-place.  These are vessels that include all of the inherent versatility of the center console configuration with hull sizes large enough to potentially provide the owner/operator more comfort and stability at higher speeds, safety for longer distances in demanding sea conditions and new destinations and fishing grounds becoming more attainable.  As in all things, quality of execution is of critical importance.

Proper design features, structural engineering, and build quality become ever more important as vessel scale grows.  The achievement of all of these goals can either make or break the entire ownership experience.  As Scott Henley, co-owner of Bahama Boat Works, says: “It’s the difference between constantly fixing or enjoying your boat!” 

In this series of articles we will be breaking down 3 quintessential aspects:

• Engineering factors

• Quality of manufacturing

• Design features

Bahama Boat Works considers these components mandatory in order to enjoy years of trouble free boating satisfaction and most importantly SAFETY and sustained value of these amazing “super-center-console” vessels.

Stay tuned for the next article addressing “make or break” engineering factors.

Contributing Authors to this series: Scott Henley, Bob Sparks, Zed Bennet, Brian Pandiscio