News:
Many of our kits are now delivered with CNC cut jigs. The jig is assembled like a puzzle. In most cases, the builder does not even need a tape measure. The jig is self-aligning: it is very difficult to make a mistake.
Transom and Motorwell Details
Transom Fiberglass
The transom of an outboard powered boat is subject to high stress
including torsion loads. Please pay particular attention to the
fiberglass lamination around the transom. This file reviews the
most important points of that fiberglass structure.
(The drawings below are not specific to one boat.
Tabbing means building a seam between two parts with fiberglass
tape on a fillet.)
We assume that all fiberglass laminations between hull panels,
frames, bulkheads and stringers are complete.
For all boats, the fiberglass laminations around the transom are
made of more layers of tape than the other parts of the boat. See
the plans for exact specs.
The stringers are always tabbed to the transom with the same type
of glass and number of layers than the stringers to hull
bottom.
At this point, your hull structure is similar to a production
fiberglass boat and at least as strong. The production boat will be
fitted with a deck and sole in one or two parts. In most cases
those molded parts will be fitted to the hull with fasteners and
sealant. Those parts do not add strength of the typical production
boat.
In our boats, we will integrate parts like the motorwell, sole and
deck in the structure to build a stronger and stiffer boat.
In some cases, just like the transom, the motorwell bulkhead is bonded to the hull with more layers than the other bulkheads, see your plans.
The motorwell sides play an important role in the structure of your
boat. They must be fiberglassed to the motorwell bulkhead, the
bottom panel and the transom with the same type of glass and number
of layers than the stringers to the bottom.
In some cases, the motorwell sides are epoxy glued to a stringer
and considering that the stringer is already tabbed to the hull,
only one side will be tabbed.
The bottom of the motorwell must be tabbed all around to the
transom, motorwell sides and motorwell bulkhead.
Not shown: the sole is installed on the stringers and tabbed to the
hull sides and to the motorwell bulkhead with fiberglass tape. The
sole participates in the structure: do not omit the tabbing all
around the sole.
If there is a sole extension in the side lockers, it must tabbed
all around in the same manner than the motorwell bottom.
This complete assembly, hull shell with transom, stringers,
bulkheads, motorwell "box" and sole becomes a very stiff monocoque
(egg crate type) structure in which the loads are properly
transmitted from the engine clamping bracket to the whole boat, not
just the transom.
Heavy Duty Reinforcements:
If you plan to install an engine larger than what we specify or
expect unusually heavy loads, you can reinforce the structure even
further. In most cases, the deck is welded to the hull and
bulkheads with cleats and epoxy glue. You can improve the deck to
hull bond and increase the strength and stiffness of your hull by
tabbing all around the deck: between deck and all hull parts, with
one layer of the same tape used in the motorwell. The clamping
board can also be capped with one layer of the same fiberglass tape
(not shown).
Those reinforcements are not required for normal use within
the engine HP range that we specify.
General remarks about fiberglass:
Always offset the edges of fiberglass layers to avoid stress
concentration.
Extend the fiberglass tape and fabric beyond the corners and edges:
Round the corners of the transom at motorwell.
If you did not find the answer to your question, please use our message board and we will respond within a few hours.
Or explore the HowTo files at our technical support web site bateau2.com