MacGregor 70... Factory web site
MACGREGOR 70 "ANTHEM"
MACGREGOR 70 SITE MAP
This is the mold from which the 65 hull is produced. It will be polished and waxed. The white exterior hull finish will be sprayed on the mold, followed by many layers of hand laid fiberglass mat and woven roving. Each layer is impregnated with resin and cured.
These are the continuous longitudinal stringers that provide support for the hull shell. The continuity of the stringers eliminates "hard spots" which create high concentrations of stress. The raised area across the centerline is a 3" thick solid fiberglass layup that carries the loads imposed by the keel.
This picture shows the transverse bulkheads that support the hull stringers and hull shell. These bulkheads are bonded on both sides to the shell and stringers with 1/4" thick fiberglass layups. Few boats have this many full bulkheads, and they give the hull tremendous stiffness and strength.
are the individual fiberglass liners that fit between the bulkheads.
These form the floors, berths, seats and interior cabinetry.
Each liner is produced on its own mold.
These liners bond to the hull and bolt to the bulkheads and add a great
deal to the structural integrity of the boat.
This is the upside down deck, without the cosmetic liners that form the ceiling. You can see the stringers that give the deck its stiffness, and the partial bulkheads that bolt securely to the tops of the hull bulkheads. We use heavy, solid laminates rather than low density cored construction for strength and stiffness.
On the North American continent, we can ship to you by truck. Here you see a 65 being loaded on a container ship. This boat is headed for Spain. Most 65s are launched at Newport Beach, California, near our plant, and sailed to their home ports throughout the world.
CONSTRUCTION: The 65 is an American built boat that offers craftsmanship unexcelled anywhere. It is built to outlast all of us. It offers the highest quality fiberglass construction. Each boat is built of individual layers of fiberglass fabrics, laid in place by hand, in a carefully controlled process. Hulls and decks are extremely strong, with extra reinforcement at all high stress points, such as the areas around chainplates, rudder fittings, the mast base, and under all other load carrying hardware.
The 65 has a one piece hull. Many cruising boats are built in separate mold halves and joined at the centerline. There is no continuous fiberglass through their centerline joints. This is risky practice and these boats should be avoided.
Many other builders use "chopper guns" to build their boats. These are devices for spraying a mixture of resin and very short strands of fiberglass. We don't use them, even though they reduce cost. They do not, in our opinion, give adequate impact strength or controllable hull and deck thickness. It is too easy for the operator, no matter how good, to miss a spot, and it is almost impossible to inspect a chopper gun layup after it is built. With a hand laid hull, it is very easy to count layers of woven fabric. Since each layer offers consistent thickness, you are sure of having the proper fiberglass content. The hand layup system provides a higher ratio of fiberglass to resin, resulting in a stronger, lighter boat. Chopper gun laminates are brittle and more prone to failure. We use only hand layup, with a high percentage of woven fiberglass reinforcement, because that is the system that builds the best boats.
builders continue to mix resin and catalyst (the catalyst causes the resin to
become hard) in gallon buckets and apply the resin with a brush.
Using that method, it is virtually impossible to determine if the
catalyst ratio is right and the resin stirred properly.
It is also hard to control the amount of resin applied to the
fiberglass. (The fabrics seem to
soak up any amount of resin and
the result can be a seriously overweight boat.)
We use automated spray equipment that injects the catalyst in exact
amounts at the head of the gun, mixes it completely, and applies it uniformly
to the fiberglass. These systems
are expensive, but reliable. Improper
catalyzation is, in our opinion, the leading cause of blistering that can
occur later in the life of the boat.
We have been remarkably free of this problem, and
We have stayed away from sandwich construction in the 65 hull. We use only solid fiberglass laminates. Foam cores, often used by competing builders, offer less than 200 pounds of adhesion per square inch. That is not much better than rubber cement. The resin bonds that hold our hull laminates together will take over 2500 lbs per square inch to pull apart. Polyester resin, which is one of the basic materials used in virtually all modern boats, is not totally impervious to water absorption. For this reason, we do not use balsa core in the hull. If exposed to water for long periods, the balsa can rot and literally turn to mush, causing major structural problems. Balsa is fine, in our opinion, for decks and structures that are not constantly immersed in water (as long as there is no balsa near holes for mounting hardware), but we, and many other quality builders, shy away from balsa below waterline.
All fittings are thru bolted, with heavily reinforced pads to carry the loads. Side shroud, backstay and forestay chainplates are bolted directly to the heavily reinforced hull, not bolted to bulkheads that are bonded to the hull. The hull at the chainplates is 1 1/4" thick. Recognizing that leaks resulting from badly sealed hardware attachments can drive the owner crazy, and that a completely dry boat with a dusty bilge is one of sailing's great joys, we spend a lot of time and effort to seal and test all attachments.
The hull and deck are joined with 3/8" stainless steel bolts on 4" centers. The joining flange is external so the bolt holes do not penetrate the interior of the boat, eliminating a potential source of leaks. The hull-deck joint is one of the strongest and most leak proof available on any yacht. We have yet to have a leak with this system.
The mast steps on a transverse solid fiberglass hull beam, 20" wide and 3" thick, including the hull. This beam also supports the forward end of the keel. It extends sideways to pick up the chainplate loads. There are 6 similar beams, 3" thick by 6" wide, thru which the keel bolts pass .
KEEL: The keel is a 12,000 lb. conventional NASA 9% airfoil shaped lead fin with wings, bolted to the hull with 13 1" stainless bolts. The bolts pass through 3" thick solid fiberglass. The draft is a very shallow 6', which will allow you into most great cruising areas. 6' of draft is about it for many good cruising areas, particularly in the tropics. The quietest and calmest anchorages are usually nearest the shore. You will spend a lot of time at anchor, where comfort is a big thing.
We have built several of the 65s with 8'6" draft conventional IOR type keels, but we find a negligible performance difference between the 6' draft winged keel and the deep keel . The winged keels really do work, as the America's Cup participants have found. The center of gravity on the deep and shallow draft keels is identical. There is no reason to lock yourself out of the best cruising waters for a marginal improvement in windward performance.
keel exerts less force on the
hull if you really plow into something solid on the bottom, so the chance for
damage is less. (It is comforting
to know that we have had a number of the 65s run aground at over ten knots
with no hull damage.)
MAINTENANCE: The boat is designed for easy world wide servicing. The engine and related components are standard items available throughout the world. The solid, all fiberglass construction, with no sandwich core material, makes damage less likely and far easier to deal with if it should occur. Everything is easy to fix.
To allow the owner or charterer more sailing and less work, we have tried to keep the boat extremely simple and as maintenance free as possible. There is no wood to refinish, no complex systems to keep tuned, and a minimum of potential opportunities for electrolysis or corrosion. An occasional polishing and waxing, care of the sails and the engine, periodic inspections, zinc changes, and the usual haulouts and bottom jobs, should be all that will be required.
The mechanical and electronic systems are spread throughout the boat and are easily accessible. With most other boats, everything is in the engine room, and it is usually necessary to sprawl across a hot engine to work on such things as bilge pumps, water heaters, steering, etc. In the 65, only the engine and its related equipment are located inside the engine covers.
Placentia, Costa Mesa, California, 92627,
642 6830 FAX (714) 642 5379 or (714) 642 5558
45 minute video is available for $10, showing all aspects of the MacGregor 65's
design, construction and performance.