Building the bimini in June, 2013

September 3, 2013 in Blogs, Equipment

Building the bimini in June, 2013

This will be our third hard bimini. We built the first one in Venezuela in 2006. We made that one with three sheets of 3/8ths inch plywood, mounted on our old soft dodger and bimini frames we had since leaving Toronto in 1998. Even though epoxy-treated and painted, it rotted out in a few years, and we replaced it with three sheets of extruded PVC from Laird Plastics in Toronto in 2010. It worked well, but we had to destroy it as we saw no way we could transport it with Veleda on a flatbed truck when we shipped Veleda from the Corpus Christi area of Texas to Bellingham, Washington in May of this year, 2013.

We have made minor modifications with each version, but basically used three 4×8 sheets mounted on the original stainless steel tubing frames from Natty Dodger at Genco in Toronto.

The list below indicates most of the purchases made to assemble and mount the new bimini in June of 2013:

Materials

      Three 4×8 sheets of ¼ inch extruded PVC from Laird Plastics, the third sheet cut to our specifications

      Fiberglass cloth strips to cover 80 square feet of surface

      Sufficient epoxy to soak the fiberglass stripping and to use as glue and reinforcement for the seams

      Cans of epoxy primer and white epoxy base paint

      PVC glue for minor tasks

      Brass and stainless steel screws for strengthening attachments

      Stainless steel half loop brackets to attach to support tubing

      Miscellaneous stainless steel screws, nuts and bolts for attachments

      PVC plumbing fittings for corner drains

      ½ inch PVC tubing for stern support posts

      PVC plumbing end fittings to attach to PVC ½ inch tubing

We spent $927.32 CDN for all of the above materials (thanks to Judy’s good record keeping). This figure does not include the frame which we had from our old fabric dodger and bimini 17 years ago.

 

Assembly

      Two 4×8 sheets were butted together lengthwise and the remaining sheet cut lengthwise for a stern panel 22” x 96” butted, to give us a bimini cover of 8 feet wide by 9 feet 10 inches long. They were butted using epoxy as the glue.

      The seams were fiberglassed top and bottom.

Bimini-1

            

Seams fiberglassed

      A one inch stringer was glued with epoxy down the underside of the centre seam for strengthening and mounting of electrical fittings.

      One inch stringers were glued with epoxy on the underside on the front and both sides (for strengthening and thicker mounting surfaces).

      A three inch stringer was glued with epoxy on the underside aft to accommodate four support posts.

Bimini-2

                                 Underside of bimini with side and central stringers

      One inch edges were glued and screwed on all four edges to channel water off the top surface.

                                        Bimini-3

                                         Top surface with edging attached

 

      When the above assemblies were attached and hardened, the bimini was turned top side up and fiberglassed.

      When the fiberglass was hardened, the upper surface was lightly sanded and coated with two coats of epoxy primer and two coats of a white epoxy based paint. (As a friend advised us in Hooking Bull Boatyard in Rockport, Texas, three important things to remember when assembling PVC, fiberglass: epoxy, epoxy, and epoxy!)

      Holes to take ½ inch fittings were drilled at the two front corners for water drains, and PVC plumbing fittings were epoxied in to attach drain hoses.

                           Bimini-4

                                    Under surface drain hole PVC fitting

      An elliptical one inch by half inch hole was drilled in the aft centre to accommodate the aft stay when mounted over the cockpit.

 Bimini-5

Hole drilled for aft stay through underside stringer

Note the three inch aft stringer for mounting aft posts

 

The above completed the assembly of the bimini, ready for mounting.

Mounting the Bimini

With the help of two boatyard workers we (Judy and I) carried the bimini down to the landing stage beside Veleda, which was now in the water.

      We raised the stainless steel tube frames (which were original with our old soft bimini) above the cockpit ready to place the bimini on them.

                          Bimini-6

                     Judy holding the forward support ready to lift the bimini onto it

(Note, the aft arch which was damaged has been replaced by a straight tube)

      With the help of a couple of other boaters we lifted the bimini and carried it over to Veleda and perched it on top of the stainless steel tubing.

      We then secured the bimini with three half-round brackets onto each of the tube frames, attached with through bolts, washers and nuts, waterproofed with Sikaflex sealant.

      The aft stay was threaded through the hole predrilled for that purpose and connected to the aft turnbuckle and tensioned.

      Two inch square bases were made, by gluing four two inch square pieces of extruded PVC together and drilling a half inch hole, to accommodate the PVC tubing used for stern support posts. When properly positioned, these were then glued to the three inch strip glued to the underside aft section of the bimini.

                          Bimini-7

 Square bases for stern support posts

      Four pieces of PVC tubing were cut and mounted so that there was a curve supported at the aft end to assist water run off (the tubes were mounted with a PVC end plumbing fixture selected to fit into the four openings of the stern pulpit stanchions).

      We then mounted a three inch wide strip on the underside central one inch stringer to help conceal the wiring that would be mounted. (I didn’t want the bare wiring showing on the underside of the bimini.)

                                                             Bimini-8

Strip concealing the wiring

   (Note the half round brackets attaching the bimini to the tube frame)

      PVC awning tracks were mounted just inside the outer edges on the underside to accommodate the side curtains and the dodger (The sewing and assembly of the dodger and side curtains will be described in a separate blog).

      A PVC tube support was mounted at each of the two forward ends of the bimini to support the outer edges.

                              Bimini-9

Forward bimini PVC support post

      Wooden blocks were mounted on the curved tubes to reduce the arching of the bimini. (Note the wooden block in the above picture with an LED reading light mounted on the aft end.)

      Electrical fittings were then mounted in various locations under the bimini. These included: a PVC electrical junction box with switches for the horn and anchor light; the horn on the underside front of the bimini; an LED anchor light mounted on a PVC tube attached above back of the bimini along with the Navtex antenna; two LED reading lights mounted on the wooden support blocks on each side, with their switches mounted on the central covering strip. In addition we have two 85 watt solar panels mounted on top of the bimini.

      After all this was mounted I then did a light sanding to clean up epoxy spills and smooth out any rough fiberglass, and painted with white epoxy paint the fiberglass seams, and the blue PVC cement we used for gluing  the various PVC fittings.

      The final attachment was the remaining curved arch (from the original soft bimini) which we mounted outside and above the bimini to serve as a boom crutch.

All of this had to be tailored and carefully measured to our cockpit dimensions (Thanks Judy!). We are happy with the system, although if doing it again we would go for 3/8th inch extruded PVC for greater rigidity, but we like our basic design which utilized existing stainless steel frames from our original soft bimini. The actual construction and mounting of the bimini took only eleven days, several of which were waiting for the epoxy and fiberglass to harden as we had a few days of rain in that interval.

Pros and Cons of a Hard Bimini

Pros

      It serves as a good mounting platform for many items such as reading lights, horn, various antennae, and solar panels.

      Not only is it waterproof, but is also a good rain catcher.

      It provides a structure for attaching a soft or hard dodger, as well as side curtains which provide good rain protection, and makes the cockpit into an add-a-room for all weather use.

      Serves as a base for a boom support.

      Extruded PVC can outlast any fabric bimini.

      The unit can be built and mounted in five to ten days of DIY work.

 

Cons

      It cannot be removed for hurricanes or truck transport. (We lashed it down with extra lines for the two hurricanes we have encountered. If we are to ship Veleda by truck again, we would cut the bimini in half if necessary to ship it with the boat, if it could not be shipped removed, but whole.)

      Cannot see the mainsail set. (We have a wind speed and direction instrument as well as tell-tales on the shrouds.)

      Getting in and out of the cockpit involves a bending maneuver.

      In our design the frame extends to the outer edges of the toe rail, and is vulnerable to damage.