how to build a seakayak/ PART EIGHT

How to build a seakayak /PART 8

Eighth part of our tutorial on how to build a seakayak Bette 500 HV, using plywood and epoxy resin , with the so called “stitch and glue” system

building the seat and assembling seakayak deck and hull

time required:

  • building and gluing the seat , backrest and footholds : 5 hours
  • assembling hull and deck together : 5 hours

we’re ending our building process, so I sum up in this episode several operations and a huge amount of pictures

building the seat, the foot hold and the backrest

at this stage we ended operations on the hull both on the inner and on the outer side; now we have to place on it the seat, the foot holds and the backrest, before assembling hull and deck together.

Most of the parts involved are made in 8 mm plywood, so we have to glue two layer of 4 mm plwood together to reach the proper thickness. To do this we choose some pieces among the plywood clippings that we have.

Verify the dimensions: loft the parts on a cardobard sheet to verify that their dimesions are ok; this is useful since small changes in bottom panels angles may lead to important changes on this parts’ shapes. So we verify the lofting, we correct some shapes if needed and then we can cut the parts on 8 mm plywood

gluing the foothold supports:

we glue them with thickened resin and a good resin radius on the hull, check their position and hold them in place with some strip of adhesive tape until the resin has set. The holes allow us to set the exact position of footholds



water drains: we make some small (8-10 mm diameter) holes to let the drain flow in the lower part of the hull

gluing the seat to the hull:

-the seat is basically a rectangular piece slightly bent to be more confortable: we use two layers of 4 mm plywood , the sequence of operations will be the following:

-glue three small battens (1×2 cm) on the lower 4 mm seat panel (they stiffen the seat)

-screw together the two 4 mm seat panels glue one on the othyer, and screw them on their cradles, so that when the resin set they’re glued with the right curvature

– remove all the screws

-glue the seat cradles on the hull

-glue the assembled seat panels on the cradle, keep it in position with screw and remove them once the resin has set

how to bend plywood: basically plywood has one direction on wich you can band it easily; use this property to cut the seat panels in a way that let them bend easily






building the backrest

the backrest has to be done in a single layer of 4mmplywood; you may bend it soaking it with hot water and leaving it under a load for 8-10 hours until it dries taking the proper shape; now we can glue on it two small supports where our nylon belts will keep it in position.


backrest hull fitting points : the easiest way is to screw the 4 ss steel buckles on the hull with nuts and bolts; I preferred to go for a slightly more complicated way, since I didn’t want to have nuts visible from the outside of the hull: so I glued the nuts with their heads encapsulated in a small patch of 12 mm plywood on the inner side and fitted the ss steel parts and the plastic buckles on them. Pictures are quite self-explaining


backrest position is very important: I’ve done a mistake gluing the backreast support too afterward, and then I had to compensate correcting the backrest panel, now everything works perfectly

seat and backrest comfort improvement:  I glued a layer of 5 mm neoprene (the one used for making wetsuits) both on the seat panel and on the backrest,  improving significantly the comfort



deck-hull joint

last stage of seakayak building, nothing too much complicated, just few tips to which pay attention;

-sanding the joint area: we sand the area involved in the joint, that’s to say a strip of few centimeters on the hull and on the deck edges

-assembling hull and deck of seakayak with cable ties: same thing that we did some episodes ago: put all the cable ties in place without closing them, once they are all positioned, close them , starting form the stern or the bow, taking care to close 4-5 of them on a side and then close the others on the opposite side,  go on like this on the whole hull; when we close the ties we have to pay attention that hull and deck are in the right position, if needed force them in the right position with a small blade or a screwdriver, lock all the cable ties




-gluing seakayak hull and deck together: we glue them with thickened resin pushed in the joint with a steel putty knife, pay some extra attention for the very bow and the very stern zones, since we won’t have any access once we assembled hull and deck; avoid to resin the cable ties,


-sealing the bulkheads-deck joint: we’ll use the pastry chef small bags to do a wide and clean joint with thickened epoxy , sealing all the space among bulkheads and deck

-cutting the cable ties: once the resin has set, we cut the ties with a sharp knife, as always

-sanding the hull deck joint: we use our powered sander to fair and smooth the joint, as always pay attention to the dust , don’t work too hard with the sander or you may split hull and deck in some areas !



-laminating the glass tape on the joint: basically same operation that we did several times during the building: a layer of liquid resin, than we put inplace our tape adjusting its position to have a smooth curve line, and then we soak it with the right amount of liquid resin; we’d better do this operation in 3-4 sections for each side of the hull, but without cutting the tape;



-final sanding: just a quick final sanding on the joint and a final layer of liquid ersin to fiar perfectly the joint

the seakayak building is complete, now you just have to launch it !