Sea kayak bulkheads are essentially walls that create compartments within the sea kayak. These compartments serve a number
of purposes. They provide for dry storage in the kayak's bow and stern hatch areas as well as providing floatation when the kayak's
cockpit is swamped. They also reduce the volume of water taken into the kayak during a capsize, thus making the
kayak more manageable and requiring less water to be pumped or bailed. The following diagram shows the usual placement for the bulkheads in sea
kayaks. All of our sea kayaks designated with an 'X' have both bow and stern bulkheads. The Q300S and Q400S kayaks only have a stern bulkhead.
In composite sea kayaks there are generally three types of materials used for bulkheads, composite, foam or plastic. We have experimented with each type
and have determined that a properly molded and installed composite bulkhead is far superior to any of the other alternatives. Foam bulkheads
being made of polyethylene pose the problem of being able to securely affix them to the kayak as there is virtually nothing that likes to stick
to polyethylene. Given all the flex that occurs in the life of a sea kayak we simply aren't comfortable with their long term prospects.
Many of the larger builders use ABS plastic bulkheads, this is done primarily for one reason, they're very cheap to produce and ABS is an inexpensive material.
However, like all thermoform plastic ABS loses its plasticizers with age and becomes increasingly brittle. We have also seen these bulkheads come
loose due to poor installation technique and materials.
We think that composite (fiberglass, Kevlar, carbon) kayak bulkheads are by far the best when
done properly. We do not like the technique many builders use of installing a flat plate and then "glassing" it in with strips of fiberglass mat or
tape. This can result in a very stiff ridge in the hull that may create a stress riser and lead to cracking over time.
Our touring kayak bulkheads are individually hand molded to match the construction of the kayak and perfectly shaped to fit the interior contours of the deck and
hull. In the diagram you see that we put a generous radius on the bulkhead to eliminate a stress riser. Then the bulkhead is fused to the kayak using
the same material that we use to fuse the deck to the hull. This material, even after cured, stays flexible and has an elongation of 120%.
Finally
we seal both side of the bulkhead with marine grade 100% silicone to ensure they are watertight and to provide additional cushioning.