45' solar catamaran

Absolutely! Roof will have 2° slope to the front and 2° to the side.

Interesting. That can save me a good chunk of money and weight.

The roof is far from being large enough for my need of 11 kW of solar panel. So, panels will be fix on their own aluminum frame.
This frame will be fix on hulls and cabin structure. The roof will stay ''unload''.
The frame is represent in green in below 3D model. Yes, I have to design this very well in a not so far future.

 

What supports the roof foam?

 

Current wood/carbon fiber structure of the original cabin.
I will fix the new roof on this structure and add a structure in the new front part of the cabin (where the new 4 opening windows are).
On picture, the two red area are current cabin structure left in place and in pink is the one I have to build.

 

So, this is important. What are your spans?

 

Ummm! Please enlighten me on this.
Width is 22'.

 

Roof spans. How far apart are the things supporting the 2” foam?

 

I plan to keep central beam from the original cabin and all structures on perimeter. (red on top view)
I also want to keep a beam (green) in the middle who will support the central beam and will support solar panel structure too.
There will have a structural wall in the front (green rectangle) to support roof and solar panel structure.
So, the largess unsupported roof area is 6,5' x 10,5'.

 

It is too big..

You hit some big waves on the great lakes and that thing is gonna bounce..

I don’t have the ability to tell you what to do, but I know that 2” xps and two 1808 is not gonna cut it.

What was there before you got it?

 

Before there was a 63 feets mast, many pulley and rails fix to the roof and the entire roof surface need to receive 1 or 2 people to work on the sail...
The actual roof is really strong. Build from real size 2x2 each 2 feets with 1/4 marine plywood on each side + fiberglass epoxy. And there is foam between 2x2.
So yes, I expect the boat to lost some weight by removing a part of this roof.

Your comment about the big wave, is it about the weight of the potential water going over the roof?

 

Sure it's because I use to work with metal and it's my first experiment with fiberglass, but I'm really amazed of the result (rigidity and stiffness).
I can jump on it and it barely move despite it is not well support/fix as it will be on the Cat.

First half of the roof is done(191'' x 80''). One side is biax 1808 fiberglass and other side 24 oz 45°x45° fiberglass.
No one of the two was able to bond on the 90° wood side despite I did 1/4'' radius on the 1/4 plywood glue around the foam.
Still the wood is bond to fiberglass on the radius, so it is strongly fix to the foam and glass.
24 oz was a real pain as it don't wet well as the 1808 did. I put a complete gallon on the 24 oz (191'' x 50'') and was forced to flip it on the foam with epoxy to be able to have fiberglass bond to the foam.
It's was way easier to simply lay down 1808 and wet it with epoxy.
I bet the cold temperature/cold epoxy (around 15-20°C) didn't help the epoxy to flow across the fiberglass.

I had to build a small Nichrome wire foam cutter and I'm really happy with it.
Cut the foam really well and precisely. Work with a Tesla 18650 battery cell

 

Yabert I am not to concerned about how you built your foam cutter as I want to put mine on a bench with a guide fence and about 300mm length, but would be very interested in the electrical components such as the diameter of the nichrome, battery details, voltage adjustment and any other components on the electrical side please? If it came from an online tutorial then directions to that thanks.

Wishing you great success with your project.

 

I built my foam cutter from a Nichrome wire found on a soldering iron I had at home.
After, I simply connect the wire to a 0-60V 5A adjustable power supply to see how it work.
At 5-6V the wire was orange-red, so I drop the voltage to 3,7V who is the nominal voltage of a 18650 cell and it cut well on 1-3/4'' foam.
Wire is in fact two smaller twisted wires and the diameter is around 0,016''.
I bought 26 Ga (0,016'') Nichrome wire for future cuts. For 12'' you will probably need 3-4 time the voltage I used to have the same power per inch (same wire temperature).
Some wire supplier give the value of Ohm/ft in function of wire diameter, so you can calculate how much power you will obtain at XX volts.
My 4'' long wire cut into foam with only 7-8 watts. That give you an idea.
Finally, remark that one of the two bolt who fix the wire is insulated from the steel frame. If no, there is short circuit via steel and no power in the wire.

 

Thanks very much, once again impressed at the power of lithium batteries, one 18650 cell did that. I was thinking of using an 18v power tool battery, so will experiment with voltage.

 

This small cells can be discharge at near 100W and I discharge them at 7-8W with the foam cutter. So, small job for them.
Not like when they have to output 760 000W in group to move a Tesla S from 0 to 60 under 2 seconds

I'm about to start the second half of the Catamaran roof with the same procedure I did on the first half.
So, if someone have comment to improve my work or the result, please let me know.

 

This Nichrome wire was useful today as the original wire broke in two at a moment I applied a little bit to much force on the foam cutter.
This 26Ga wire have lower resistance and then become orange (really hot) when put in place of the original wire.
Solution: I simply add 1'' on length to the wire and it stay cooler... still cut faster than the original wire.