Bimini top out of aluminum ?????

[Freshly Hooked]

HI

So I have a aluminum framed canvas toped bimini. The canvas is in need of replacement and I want a more durable top that won't need to be replaced every few years and will be better for mounting flexible solar on. Also as this is on an Ourtemer 55 I want it to be as light as possible. I have been staring at my Bimini for months and then it hit me why not use 1/16" aluminum. Then it hit me "I've never seen anyone else do that" I don't need to walk on this as there are boards that run for and aft on both sides of the boom but I do want it to be rigged and not move in the wind.

So what do you all think of this ???????

A few other facts that might be helpful

There are lateral supports every 2'10" or less

The aluminum I'm thinking of using is .88 lbs per ft2 the Bimini is 124 ft2 so it will be aprox 110 lbs

[Tafa]

Downsides I can think of....... The load would be quadruple or more with the windage. You'll need the asses the strength of the frame. It may end up ripping off all frame and anything mounted on top.

Not sure about the heat absorption ... But I believe it will be way hotter than canvas or white painted marine plywood.

[Freshly Hooked]

Good points

If I paint it white would it still have more heat absorption then other materials because its metal ?

[Tafa]

Aluminum is highly conductive.... even as painted, it will absorb much more heat comparing to wood or plastic.

Two friends of mine have made hard biminis out of King StarBoard (polymer sheet) and it's working fine for them for 3 years so far. http://www.kingplastic.com/

But again, the strength of the frame should be assessed thoroughly.

[Tortuga's Lie]

Starboard is a great product but it does have it's limitations. One being that it is very heavy for it's size and the second is that it is non-structural. You would still need to build a substantial skeleton to support a skin of any type. Starboard is also very expensive, OK...that's 3 limitations

[Bill O]

I'll go against the flow here and say the aluminum would be a a great top for the bimini material. Lots of work boats here with hard tops to hold traps/other gear and ultimately they go to aluminum for their top.

Maybe a bit costly for your size boat and in the end would probably weigh less than any other hard top material. Can't see your frame to tell if it would be strong enough, but once the plate is mechanically or welded in place it will stiffen it up quite a bit. While not as big as yours, our top has seen > 60kts and no problem. We also have solar panels mounted and we walk on our top regularly. Check with a welder/your fabricator if 1/16 plate would be enough or if 1/8 would be better.

Painting it white will help to keep the heat down. We added 1" blue board insulation under our top and it's great. Even > 100F it's nice and cool underneath the bimini. Down side is you will probaly want to add a finishing skin to hide the insulation.

Bill O.

[MV Wanderlust]

The idea of painting it will help reflect some heat but there may be an even better option. We painted our hardtop with elastomeric paint used to coat the top of mobile homes. Those are also made of aluminum so it should work great for you. We picked it up at Home Depot and one gallon was way more than enough to put two coats down. The paint goes on blue but dries white and leaves a kind of thin, rubbery coat. The resulting difference in temperature under the hard top was impressive. Might work well for what you're planning.

[Typhoon]

Originally Posted by Freshly Hooked

HI

So I have a aluminum framed canvas toped bimini. The canvas is in need of replacement and I want a more durable top that won't need to be replaced every few years and will be better for mounting flexible solar on. Also as this is on an Ourtemer 55 I want it to be as light as possible. I have been staring at my Bimini for months and then it hit me why not use 1/16" aluminum. Then it hit me "I've never seen anyone else do that" I don't need to walk on this as there are boards that run for and aft on both sides of the boom but I do want it to be rigged and not move in the wind.

So what do you all think of this ???????

A few other facts that might be helpful

There are lateral supports every 2'10" or less

The aluminum I'm thinking of using is .88 lbs per ft2 the Bimini is 124 ft2 so it will be aprox 110 lbs

I am building one right now . Presently it weighs 135 lbs .
You have probably already seen this thread .
http://www.cruisersforum.com/forums/...-197990-2.html

Regards John

[Scout 30]

Home | Hard To Top

[Bill O]

Originally Posted by Scout 30

Home | Hard To Top

Yes our friends Chuck and Susan (who are used as their example) on Beach House used this material. It was a light weight honey comb translucent polycarb material. It let's some light through. They liked it.

Would avoid needing to paint it also.

Bill O.

[Cheechako]

1/16" aluminum is probably going to get rippled and a bit ugly.
Unfinished aluminum will get heavy grey oxide that gets on everything it touches.
Painted aluminum often loses it's paint regularly. (my friends had their aluminum cutter pro painted 3 times in 10 years)
It's much heavier than canvas.
Starboard is very heavy.

[Hardhead]

I think it's a great idea. I'd paint it white and use the RV paint described above. Easy maintenance and great durability. Good thinking-

[conchaway]

It depends on how much you like St.Elmo's fire.

[Cadence]

Make sure it's got a good path to ground.

[Dymaxion]

Noisy in the rain...
We had an old Land Rover, aluminium roof. It had a 2nd alum'n roof skin screwed to original roof ribs. Air flowed between the two layers and kept things cool(er). This might work with two thin skins and stiffen up the whole thing depending on rib size/spacing.