Disclaimer – This project is in progress on a fully functional cruising boat currently afloat. Final gel-coat finish and canvas work is not yet complete.
A little more than a year ago, we decided to engineer a complete hard top for Take Me There. Our canvas Bimini and dodger had seen better days and a hard build out appeared to be cost effective if we tackled most of the work ourselves. It wasn’t easy but it was possible. In fact it’s still a work in progress but now the shell is up and functional. Below is a photo of our vessel with the original canvass dodger and bimini to give some context on our starting point.
Our goal was a near identical profile of the canvass structure but with poly-carbonate windows in the dodger and removable/adjustable windows in the surrounding enclosure. The design allows:
(1) a 200 lb man to walk/stand on top to service boom rigging – but not exceed 400 lbs of structural weight.
(2) addition of another 580 watts of solar panels to the top (total of 1160 watts)
(3) full enclosure from the elements with access to running rigging control underway
(4) the cockpit space to be sealed enough to defend against bugs, permit air conditioning/heating of the space and, of course, shade from the sun.
The frame super-structure is built from 1.5 inch OD 6068 aluminum pipe (with speed-rail connectors) – photo below:
The dodger and top are fiberglass (and eventually gel-coat) laid over a Divynlcell core material. The dodger is engineered from a 5/8 inch thick Divynlcel structural foam. Its design is intended to bear the weight of the top (forward) while the aluminum superstructure provides integrated strength and support mid and aft of the entire cockpit (Photos Below):
This photo shows the dodger (glassed) and in place (for fitting) and how it integrates with the aluminum superstructure to support the large top pieces.
The top sections are 12 feet long and 4 feet wide (each)(2 panels) and the dodger/top/frame combination weighs under 400 lbs…a nice “front porch-like” space starting to form.
Each of the 2 x top sections are 2 inch Divynicel foam, joined together and stiffened with oak runners before structural glassing. We embedded anchoring blocks for helicoil inserts at every point we wanted to create a mechanical joint to draw everything together. Keeping these flat during the build was one of the biggest challenges and required a large, flat, smooth concrete floor to work on.
A few shots of the assembled shell (while we were verifying and marking fitting points for the speed-rail mounts and joints at the dodger top and along the cockpit coaming.
We used gaskets designed for mounting truck camper tops to the pick-up bed to seat the dodger on the forward coaming and closed cell high-density foam gasket material (3/4 inch) for the top to dodger sections. You might be able to see the symmetry of the design in these photos. There are 6 pieces in the design:
- Dodger in 2 pieces (port and starboard) – these open and swing out like wings when unbolted from the center (and top) on the superstructure supports at the aft edge of the dodger pieces.
- Top in 2 pieces (port and starboard) that rest on speed-rail supports (the top will support 2 men easily)
- Side beauty pieces (x2) – these house electronics, speakers, wiring, switch panels and cover the aluminum supports – our intent is to add our Gulfstar Logo in the triangular white space for asthetics. The design allows us to access running rigging coming to the electric and manual winches at the aft cockpit.
We engineered a ladder into the aluminum superstructure design to climb up the back onto the top for rigging and solar panel maintenance. The small dog house on the starboard and port leading edges hold our GPS and AIS antennas.
The canvas surround and finishing out the interior is the next DIY project. The interior is unfinished at the moment until the final gelcoat work is polished and trimmed but we are fully functional for being underway.
Ok-why all the effort? Four reasons:
(1) We wanted a dodger/Bimini replacement that could take a hit (green water).
(2) We wanted better designed head-room and a platform for solar panels and boom/rigging maintenance.
(3) We wanted a cockpit that we could enjoy in all weather conditions.
(4) For the DIY price…the hard top came in at about the cost of a new dodger/bimini (under $5k)!
The top was built in 6 principal sections so it can be taken apart and serviced by 2 men without a crane (in case of damage) and it can be removed to restore the original ergonomics of the boat. We strived to design/build a “pilot house” that integrated with the lines of the boat-we think we got it right.