hard bimini?

[rmeador]

I see a lot of talk of hard vs soft dodgers, but I can't recall a mention of a hard bimini. I'm thinking I need a bimini. I know many purists will tell me I can't sail with one, but I get sunburned very easily so I think it is warranted (I promise to stick my head out to check the sail trim). I was just looking at the Atkins and Hoyle website (makers of my portholes) and noticed they do hard biminis. Wheels started turning: I want solar panel mounts on my bimini anyways, so it never made sense to me to pay for expensive sunbrella or other fabric when it is just going to be covered with panels. Maybe a hard bimini is the answer? Why do they seem so rare, is there something inherently wrong with them? Also, check this out, from the Atkins and Hoyle website (emphasis mine):

These new products are available with many options including: radar mounts, wind generator mounts, davit option for Arches, rocket launchers for fishing, and many more customized designs.

Ok, fine, so the context makes it pretty clear that this is some kind of fishing device I'm unfamiliar with, but still, some rocket launchers might make those somali pirates think twice...

[mitiempo]

Hard biminis are common. My neighbor is installing one on his Grand Banks 48.

[chuck711]

Hard Bimini are heavy and can effect sailing ( handling ).
Why not just erect a frame and put up 3 tightly fitted panels to act as bimini?

[CapnBilll]

I haven't bought one mainly because they cost more, but there are a couple of downsides.
1. the weight, I don't see this as a big deal but something to consider.
2. harder to remove, high winds they act like a giant scoop.
3. storms, for a severe one I take the bimini down, can't with a hard one.

I'm tempted any way, they last longer and rarely leak. I have a hard top for the stern, ( a heavy duty one), that has made several hurricanes no problem.

[mitiempo]

Weight up high is not a great idea. If you put 100 lbs 7' above the waterline the result is a vertical moment of 700ft/lbs. To maintain the vertical center of gravity you need 700 lbs 1 ft below the waterline or 350 lbs 2 ft below the waterline.

[Omatako]

100 lbs as a percentage of 25000lbs?

0.38%.

Still, I wouldn't have a rigid bimini but I would seriously consider a hard dodger.

[mitiempo]

The displacement of the boat makes no difference to the numbers I posted. But the heavier the boat the less actual effect it has. If you were to put 10 lbs on a mast 70 feet up you would still need the same 700 lbs 1' below the waterline to maintain the stability you started with. Weight up high is obviously more of an issue on a 30' boat than on a 45' boat.

[Boatsmith]

A hard bimini cover could be made of 1/4" foam sandwiched between single layers of 1708. I would think that it would have to be for a pretty big boat to add up to 100 lbs. Sunbrella doesn't last long enough in my opinion.

[mitiempo]

Could be.

Looking at a Taratooga (sp) hard top covering the cockpit on a nearby Coronado 35 I am pretty sure it weighs much more than 100 lbs. In addition to the fiberglass top there is the structure to hold it up. Allowing for the smaller size (probably) on a bimini it would depend on how it is built. Of course when you have a hard bimini it is a great place for solar panels - more weight. 135 watt Kyocera panels are 29 lbs each.

[micheck]

Would adding lead weight to the bottom of the keel be an acceptable method to counter the moment created by a hard bimini (with 130 pounds of Kyocera solar panels) - say 5' x 300 pounds for the bimini vs 3' x 500 pounds for the keel add on? What does that do to sailing performance?