Raising Hardtop

[PROS]

Hi All,

20ft Caribbean has a very low hardtop, comes to my chest.
Needs to be lifted 60cm to be able to walk under.
Its not a massive issue as we are used to it but if possible to get it done at a reasonably low price, I like to get the project under going.

This is how the boat looks currently,

9946099461

The height of the side window is 60cm also, easy to judge final location of the hardtop.
Excuse my basic photoshop skills as below,

9945899459

I was thinking to have an aluminium tube frame made up under the hardtop roof, having rod holders welded at the back.
At the front 2 bars with 3 spokes each structure to attach to boat.
Aluminium to save cost and weight rather than s/s, polish it or paint.

No problems with the clears to cover the gap between the roof and window as its my line of work.

Frankly, I would rather let a fabricator to do the job, any idea what should I be expecting in terms of the cost?
I am located at north side of Brisbane, any recommendations of a fabricator?
Your input about design?

Regards

Max

[Chimo]

Max

two or three points
Al will most probably not be sturdy enough to prevent side to side movement or fore and aft movement unless you use very heavy walled large size pipe. I have SS on mine and there is a smidge of side to side movement at speed in rough conditions and mine is almost over engineered.
Your existing top will need to be extended forward to give you a worthwhile and useful eyebrow so you are going to need a FRP person too to make the job look the goods.
If you going to go to all that trouble you could argue its probably worth doing something with the front and side glass at the same time (Pauly?)

A hardtop with a bit of air above the head sure is cooler!

Cheers
Chimo

[ovakil]

I made my ally hard top.I fitted styrofoam insulation as well.
Main concern was side way movement,I made some diagonal bars that sat outside front windscreen.

http://i124.photobucket.com/albums/p23/ovakil460/IMG_3411.jpg (http://s124.photobucket.com/user/ovakil460/media/IMG_3411.jpg.html)

[PROS]

Max

two or three points
Al will most probably not be sturdy enough to prevent side to side movement or fore and aft movement unless you use very heavy walled large size pipe. I have SS on mine and there is a smidge of side to side movement at speed in rough conditions and mine is almost over engineered.
Your existing top will need to be extended forward to give you a worthwhile and useful eyebrow so you are going to need a FRP person too to make the job look the goods.
If you going to go to all that trouble you could argue its probably worth doing something with the front and side glass at the same time (Pauly?)

A hardtop with a bit of air above the head sure is cooler!

Cheers
Chimo

Chimo, thanks for your input, I agree it needs diagonal support to eliminate any movement.
I was thinking; as well as 6 or 8 attachment points to the boat, I can also use the window frame as support as well to make it sturdy.
Why do you think aluminium would be very weak?
White I was searching around I saw tall tuna towers built with alloy, hence my thinking to use as the frame material.



I made my ally hard top.I fitted styrofoam insulation as well.
Main concern was side way movement,I made some diagonal bars that sat outside front windscreen.


Ovakil, did you weld aluminium yourself?
I was thinking to build it myself but bending aluminium was my concern.
Looking at your setup, its more welding than bending.

I have a mig welder and done fair bit of welding.
Never done tig though or any aluminium welding.

[Shark Poker]

Thanks for thinking of me, Chimo. As it so happens we are modifying a roof on another 20ft Caribbean tomorrow. PROS if you like I can fwd some later in the week. Pauly

[Chimo]

Pros

Why do you think aluminium would be very weak? Al is weaker than SS but if you use heavy enough Al it will be strong ie big diameter with appropriate wall thickness which will make welding easier

BUT you do run the risk IMHO of ending up with a structure that could double as building scaffolding.

At the end of the day I suspect you want form and function that adds to the boat's value rather than detracts from it?

I have spent a bit of time in a Bertie such as yours but it was an inboard and after a long day off Bermaguie with lots of engine noise resonating around a speaker box ie low hardtop I was happy to never spend more time aboard. Perhaps outboards are quieter?

Cheers
Chimo

[ovakil]

Had a mate weld it for me.
Was a big job. I had top cut & bent (join in middle). I cut all tubing &plate up myself.
Roof is mounted on original stainless centre bar, made 4 post on inside for support. The outside bars were fitted later after I discorvered roof was moving sideways to much.
Cheers

[ovakil]

Forgot to add picture,
http://i124.photobucket.com/albums/p23/ovakil460/IMG_0554.jpg (http://s124.photobucket.com/user/ovakil460/media/IMG_0554.jpg.html)

[PROS]

Thanks for thinking of me, Chimo. As it so happens we are modifying a roof on another 20ft Caribbean tomorrow. PROS if you like I can fwd some later in the week. Pauly
That will be great help I you could please forward some pics.
Many thanks
Max