Monday, June 23, 2014

Bimini top

With the prospect of being able to do longer trips thanks to the extra range allowed by the EPIRB, a Bimini shade would be a useful addition to keep the suns rays off the crew while sailing. Some Investigators have fitted 2 or 3 bow biminis, the 3 bow needed some shortening of the canvas though. A Bimini is almost essential for enjoyable boating in Queensland.

Economical mass produced off-the-shelf biminis are designed to fit small open power boats of 3-6 m LOA, nearly every small fishing boat i saw on the water in Townsville has one fitted, and the boaties looked very cool in the shade too.!  Not many small trailer-sailers have biminis maybe because of the difficulty to get them to fit among all the complex ropes, rigging, sails, hatches and deck hardware. A bimini must also have a snug and out-of-the-way lowered position for rigging up and trailering.

At home the mast and mainsail were raised and measurements taken of the available free space for the Bimini.  There was 1.2 m available space from deck to boom and 1.7m available between the boom vang and the mainsheet. The coaming width was 1.7m.

Had a look at the Bias boating catalogue and it looked like a 2 bow bimini (size C) by "Ocean South" would fit the space without modifications. Soon had one back at the boat for fitting. They are premium quality - nice yacht blue canvas, anodized 22 mm diameter aluminium tube bows and all-stainless fittings. This one cost $210.

Put it together (spring loaded push pins) and tried different base positions. It  had to go outside the coamings on deck, not on the coaming top. The deck mounts can spread out to the needed 1.83 m from their 1.7 m width to achieve this. Checked it in the raised and dropped forward positions with the bases outside the cockpit coaming. The boom was about 10 cm above the bimini top.

Shade for the forward end of cockpit and main hatch area.


The boom vang sits just ahead of the bimini. Crew can exit cockpit through the V formed by the 2 bows.

Narrow bimini allows for side deck walking access

Room for the main sheets and boom to run freely (may move the aft strap from the pulpit to the cockpit coaming)
In the lowered forward position the folded bimini frame sits in the notch between the pop-top and the mast tabernacle. This allows the mast to be dropped to horizontal in the tabernacle. It also allows the pop-top to be raised when the bimini is stowed.  This size bimini can't safely fold back without risk of breaking the base pivots. (could be possible with a wider base 3 bow bimini?)

Bimini lowered

Bimini lowered - frames lay alongside cabin, side decks clear.
Mast lowered, bimini sits in notch between hatch and mast step.




The 2 bow bimini's top canvas is only 1.4 m (4'7") wide, but the narrow top makes it easy to walk along the side decks to enter the cockpit from forward (at the expense of losing a little shade area). It also looks ok, the frames slope inwards the same as the cabin sides. There is 1.6 m (5'3") standing headroom under it. The Bimini is only 1.57 m (5'2") long so the skipper can stand up behind it and lookout over it's top.

Selleys epoxy putty was used to fill the gap between the mounts and the sloping decks. It's in tube form with epoxy and hardener as layers. Just cut a bit off and knead it awhile, then it goes on like Plasticine and sets hard in 10 minutes. (It's staying aboard incase a hole or crack appears, it can make a quick acting patch job too)

Pivot base with epoxy putty to level it securely

Deck fitting for bimini strap

The guy strap eyelets and pivot bases are screwed down to the deck.

It was cool under there already! The bimini will definitely make the decision to set sail an easy one, especially on a scorching sunny day.  It's ready to test out on the next trip..(There is one thing i may have to modify yet - the aft straps hold down position from the pulpit to the cockpit coaming,,this may increase crew access to the side deck)

Mast and bimini stowed ready for the road.

2 comments:

  1. HI Andrew, thanks for this post. I found it useful 'cos I'm planning on fitting a bikini to my Hunter 19. Ta, Terry

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  2. G'day Terry, Hope the bimini goes well, enjoy the sunny weather on the water.

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