Flybridge hard top

[ksanders]

Where did you source? I'm seeing 80lbs for 1/2" 4x8 Starboard - pretty heavy for a non-structural sheet.

Great thread - thanks for starting @ksanders - please keep us posted on your progress!

I bought the starboard out of San diego and it's being trucked to me in La Paz.

240 pounds or a bit less total.

The weight of one adult man.

My flybridge seats 8 comfortably, and we've had 26 guests on board for a party.

The boat is big, and heavy. It's been weighed multiple times on multiple slings at 47,000 pounds as is.

that little bit of weight is not a problem.

Imagine I make a fiberglass top, and save what a hundred pounds. Again thats nothing.

For example i removed a 700 pound skiff from the fly bridge deck and added a 130 pound skiff.

Here are photos of a friends boat, same model with a very similar hard top.

 

[SteveK]

Kevin, will you be adding solar and is that weight another 2-300 lbs.
what about the weight of the framework? Seems like you are adding 2-3 grown men. I recall you did or were going to do a roll test after the fins were installed, maybe a before/after.

 

[ksanders]

Agree, Starboard is too heavy in this application. Figure at least 3 sheets, that is a lot of weight up high. I patrolled Americas Cup the first year it was in San Diego aboard a 4588. It certainly knew how to roll. One crew member was sitting in a chair on the starboard side and in the blink of an eye was suddenly on the port side with the chair on top of her. It wasn’t a bad day out in the Pacific. I would want the lightest hardtop I could find up high on a 4788.

Dave, the 4788/4588 shares a rolling characteristic where if the waves, even seemingly small waves, match the natural roll period, the boat can set up a ever increasing roll.

I've seen it happen to my boat, and I've seen it happen to others. Sailboats at anchor suffer greatly from this phenonomon.

The 4788 is a soft chined hull and acts in the water differently than a square chined power boat. It acts more like a displacement hull.

This is not unsafe, it's just a characteristic of the hull shape.

My boat also has a very effective stabilization system, that dramatically reduces that tendancy.

 

[ksanders]

Kevin, will you be adding solar and is that weight another 2-300 lbs.
what about the weight of the framework? Seems like you are adding 2-3 grown men. I recall you did or were going to do a roll test after the fins were installed, maybe a before/after.

Steve, lots of folks have added hard tops to the 4788, including full on command bridges.

Never heard of one turning turtle or having problems, and I'll guarantee that the weight, of the combined structure is far less than the weight of the gigantic zodiac I removed form the fly bridge, that every 4788 owner seems to love.

I do not know the exact weight of the stainless structure. I could guess at 100 pounds, but that's just a guess. Maybe it's double that. Yes I'm going to also add renology flex solar panels at maybe 10 pounds each.

I do not know the manufacturer rating of the fly bridge, but somewhere i remember 10 people. At a industry standard 170 pound person that's 1700 pounds.

 

[SteveK]

no worries, just making sure you were adding it up. Yes I am aware and have seen cabins built with glass enclosure. Not having riden in one I do not know if there is a difference.

 

[ksanders]

no worries, just making sure you were adding it up. Yes I am aware and have seen cabins built with glass enclosure. Not having riden in one I do not know if there is a difference.

Thanks Steve. Keeping me thinking is good, that way there are no suprises down the road

 

[GB42-424]

Carbon core sells direct from their factory in South Carolina and can provide a shipping quote.

 

[ksanders]

I know folks for some reason do not envision starboard as a hard top material, and i am not sure why.

Except for weight starboard is the perfect marine hard top material if properly supported.

It is impervious to water
It will not stain
Nothing sticks to it, so it's easially washable
it requires no finishing, no painting, even on the edges, ever.
It is meant for outdoors UV rich environments.
It is easy to shape, and drill
it bends similar to plywood
It even accepts screws

I cannot think of a more perfect material.

Here is a friends or my boat with his starboard top over stainless.

 

[socalrider]

I know folks for some reason do not envision starboard as a hard top material, and i am not sure why.

Except for weight starboard is the perfect marine hard top material if properly supported.

It is impervious to water
It will not stain
Nothing sticks to it, so it's easially washable
it requires no finishing, no painting, even on the edges, ever.
It is meant for outdoors UV rich environments.
It is easy to shape, and drill
it bends similar to plywood
It even accepts screws

I cannot think of a more perfect material.

Here is a friends or my boat with his starboard top over stainless.

That does look very good - it seems like a good fit for your vessel. For me at least it's mainly the weight, which is amplified by the lack of rigidity, which means more structure is needed. I understand that you're not concerned about it for your vessel, but for mine putting 300lbs of starboard plus maybe another 100lbs of support 6.5' over the flybridge would be a significant impact to stability - not to mention if I were to stick rigid solar up there like I've always wanted to.

To me a perfect material would be something like the carbon core mentioned before. 24lbs for a 4x8 sheet, also pre-finished, so less than 1/3 the weight and much stronger. Ideally I'd fasten it to the existing bimini frame like the now-defunct HardToTop product & the resulting structure would be only marginally heavier than what I've got but vastly stronger. Lots of details that'd need attending to with a cored composite vs the StarBoard though so I totally appreciate your approach.