Blue Angel (Canados 70s) Rebuild thread

[Greg2]

The practicality of a retracting/sliding canopy has always appealed to me so I think it is a great idea. The lines look good in your sketch and the black works well......preferable to white IMHO. Not sure about which materials to HSE. I guess it will ultimately be a trade off between cost, form and function.

 

[vas]

Bart,

sketch looks good, if a bit too ideal and streamlined. I'm afraid once you start dimensioning things on a custom built basis, sizes will start growing a bit.
I'd probably avoid ply+epoxy in the normal way of application and I doubt you're going to get a custom one off grp construction at a reasonable cost...

However, I would consider 4mm ply on a reasonably thin frame (say spaced at 150mm and again 4mm thick) in the way that model airplanes are done out of balsa if you get what I mean. Then a couple of lightweight mats and epoxy would get you at a nice and smooth curved surface, light and strong. Should be doable within a few days as you can lasercut the frames at home and flatpack the lot to where the boat lives and diy the construction in situ. This way you don't even need steel frames, just strong ply flanges for the upright supports at the front.
Use Rhino for modeling and preparing the sections in closed polylines to the lasercutter, job done in practically no time!

cheers

V.

 

[Deleted User YDKXO]

I'm thinking telephone number prices for a roof like that. Apart from anything else, you would have to be sure that the radar arch and f/b coamings could support the extra weight. You see many boats with 2 biminis, one over the aft seating area and one over the helm area (folding forwards). That would be the route I would take

 

[Hurricane]

Or would you stick with a extension on the existing canopy ?
Problem is this reaches not over the FB helm position, and that’s the only position where I would like to have the roof almost permanently.
A separate independent canopy above the helm postion does not look nice I think.

Some pics from our existing canopy:

Sugestions ?

Only just picked this thread up again

FWIW, Our bimini has worked out well
Personally, I always worry what the extra drag of a bimini/hard top is creating/hindering the boat's performance.
For this reason, on long passages we mostly fold the bimini away.
It is easy to do because ours folds away against the radar arch like yours.

So, one option would be to make a new bimini that extends over the helm position in the same way that ours does.
The trick was to create an extra anchor/pivot point for the bimini frame with a sliding track (sailboat track for sheets seems to do)
This way, as the bimini unfolds from the radar arch, it also moves forward to cover the helm position.

Here are some pics of ours taken a while ago when she was new.

Yoy can see the sliding track on the left of this photo

This is about as big as you would want to go with a single (unpowered) bimini.
At the beginning of the season it is a bit of a struggle for just two of us to get the canvas onto the SS frame so we usually get some friends to help.
We take the canvas off during the winter months to keep it in good condition.
After that it is a one person job.
And it can be a bit of a liability if the wind is strong.

However, if I was doing this again, I would design the same thing again.
Generally, it works very well.
If you want instant shade, it just drops into place.

 

[BartW]

However, I would consider 4mm ply on a reasonably thin frame (say spaced at 150mm and again 4mm thick) in the way that model airplanes are done out of balsa if you get what I mean. Then a couple of lightweight mats and epoxy would get you at a nice and smooth curved surface, light and strong. Should be doable within a few days as you can lasercut the frames at home and flatpack the lot to where the boat lives and diy the construction in situ. This way you don't even need steel frames, just strong ply flanges for the upright supports at the front.
Use Rhino for modeling and preparing the sections in closed polylines to the lasercutter, job done in practically no time!

thanks Vas,
interesting method for making this hardtop,
but can you lasercut ply ? never heard about that,
How would you stick the panels on the frame, if done on location ?

I was thinking to make it completely on location, in a way that it can be disassembled in separate transportable parts:
2 x side wings, front panel, support bars, spreader bars, ....

Here in the company is a Google Sketchup training in a few weeks,
do you think with Sketchup we could do this also, or is Rhino completely different ?

 

[BartW]

I'm thinking telephone number prices for a roof like that. Apart from anything else, you would have to be sure that the radar arch and f/b coamings could support the extra weight. You see many boats with 2 biminis, one over the aft seating area and one over the helm area (folding forwards). That would be the route I would take

pls don't talk to my wife, sche say's exactly the same ;-)

 

[BartW]

So, one option would be to make a new bimini that extends over the helm position in the same way that ours does.
The trick was to create an extra anchor/pivot point for the bimini frame with a sliding track (sailboat track for sheets seems to do)
This way, as the bimini unfolds from the radar arch, it also moves forward to cover the helm position.

Hi Mike, thanks for the pics,

our existing bimini is approx the size of yours, we have similar experience, ...
but
On our FB there is a bout 2,5 meter in front, not covered by the bimini, and if we make the existing bigger (technically no problem)
then the problem is that I mostly want sun protection on the front,(over the helm) and not over the sunbeds,

So we would like to have 2 separate biminis,
and I haven't seen yet a nice construction of 2 separate bimini's on a FB like mine.
It really is a esthetics problem unless one can come up with a nice example, or nice design.

 

[vas]

thanks Vas,
interesting method for making this hardtop,
but can you lasercut ply ? never heard about that,
How would you stick the panels on the frame, if done on location ?

I was thinking to make it completely on location, in a way that it can be disassembled in separate transportable parts:
2 x side wings, front panel, support bars, spreader bars, ....

Here in the company is a Google Sketchup training in a few weeks,
do you think with Sketchup we could do this also, or is Rhino completely different ?

Bart,
you can definitely lasercut ply!
my 3D printer (MakerBot) is done out of lasercut ply together with the nice edgecut blacked from the burn...
I'd probably use a 20X40 or more as a backbone where the folding mechanism is going to bolt onto, and form the sections to accommodate and glue on this beam. Paneling will be thin strips stretched over and kept in place with elastic bands or if careful staples (will need to think and sort out detailing anyway)

Agree on two long pieces and the cross sections bolting together.

Sketchup is an excellent tool for quickly knocking up and visualizing some ideas. We've more or less banned the use of it in our dept as everything is done at no scale no sense of dimensioning and minimal care/understanding on builtability... If you spent lots of time, you may be able to do it, not sure on it's abilities on curved surfaces nor it's compatibility with proper solid modelers that you'll need at the later stage to prepare the sections/cuts for the frame. I'd say, start with what you can and I'll gladly help.

Mind, I'm going to be in Brussels and Ghent on the 21st-22nd for a meeting, if you're around and interested, I could arrange to stay a day or so more and do the design together

cheers

V.

 

[rafiki_]

Bart, while the dark colour looks great, if you build in ply, it will get very hot, hotter than a white finish, so the question is, what will happen to the ply laminations? Will the glue integrity fail? You might look at infra red resistant paint, if you can get it in the right colour? The Military use this, and it works really well.

 

[vas]

Bart, while the dark colour looks great, if you build in ply, it will get very hot, hotter than a white finish, so the question is, what will happen to the ply laminations? Will the glue integrity fail? You might look at infra red resistant paint, if you can get it in the right colour? The Military use this, and it works really well.

raf, is that similar to some experimental paints with hollow microspheres for insulation? or would that not help?

V.

 

[rafiki_]

Vas, I don't really know the paint ingredients, but on Military Land Rovers, the IRR paint really works well in reducing solar load, and interior temperature. Clearly this was NATO green, but I'm sure other colours are available. Standard white paint does not absorb IR to the same degree as darker paints.

 

[BartW]

Bart, while the dark colour looks great, if you build in ply, it will get very hot, hotter than a white finish, so the question is, what will happen to the ply laminations? Will the glue integrity fail? You might look at infra red resistant paint, if you can get it in the right colour? The Military use this, and it works really well.

good point, I never heard about IR resitant paint, but we need to give this attention if we go this route,

there are other parts of the superstructure, from wood, painted in dark bleu,
or like on Vas's Mitos, there was some black iirc
so a dark collor must be doable

 

[BartW]

Standard white paint does not absorb IR to the same degree as darker paints.

white would be better in this respect,
but both swmbo and myself prefer black.

 

[rafiki_]

white would be better in this respect,
but both swmbo and myself prefer black.

Bart, I fully agree about the colour. My point is purely that excess temperature will speed up the degradation of the ply, so is there a way of mitigating this?

 

[BartW]

, I'm going to be in Brussels and Ghent on the 21st-22nd for a meeting, if you're around and interested, I could arrange to stay a day or so more and do the design together

thanks for the kind offer,
I've just booked tickets to Venice on 20/2 for a visit to the MCY factory in Monfalcone with a friend (exciting coincidence)
on 21/2 we have the Sketchup course in our co,
on 22/2 I could make some time available,
but on 23/2 I have a "obligatory" activity with my dive club,

anyway, I don't want you to spend your valuable time on my drawing
but I'm alway's in for a meet and some boat talking
keep me updated with your scedule

Lets find the best construction method and principles on here,
and I'll have the drawings made by one of my guy's (as he's used to for all the work I did on the boat)
In his former live JT was a drawer at a builder of wooden houses ;-)

regarding the construction,
I have a few suppliers with whom we cooperate and who have big CNC routers (for cutting complex shapes from a big wooden plate )
so would be very simple to get these ribs / stringers made...

but to make the parts a perfect fit, I'll probably better integrate a Alu frame,
can be machined more accurate than wood,
very convenient for bringing the parts and the gliding system together.
I'm not sure if the mixture of ply with Alu is OK, especially with such big temp variations,
different temperature expansion coefficients ?
the design should allow room for that ?

 

[rafiki_]

but to make the parts a perfect fit, I'll probably better integrate a Alu frame,
can be machined more accurate than wood,
very convenient for bringing the parts and the gliding system together.
I'm not sure if the mixture of ply with Alu is OK, especially with such big temp variations,
different temperature expansion coefficients ?
the design should allow room for that ?

Bart, you are correct again, there will be a substantial difference in thermal expansion, alu v wood. I think you might be better with a wood frame rather with alu, and using alu for the mountings and struts.

 

[BartW]

there will be a substantial difference in thermal expansion, alu v wood. I think you might be better with a wood frame rather with alu, and using alu for the mountings and struts.

agree for the mountings,
but for the struts (= support poles ?) should be Stainless Steel, just like all other visible metal parts on the boat

 

[rafiki_]

agree for the mountings,
but for the struts (= support poles ?) should be Stainless Steel, just like all other visible metal parts on the boat

Yep, agreed. Have you considered a canvas section within the hardtop that you could roll back, a bit like the Sealine hard tops? This would reduce the mass of the hardtop, and give you some options?

 

[BartW]

Yep, agreed. Have you considered a canvas section within the hardtop that you could roll back, a bit like the Sealine hard tops? This would reduce the mass of the hardtop, and give you some options?

yes I would like exactly the same canvas & gliding system as on the pictures in post #680
this is made by Opac Mare (one of their departments that makes foldable roofs for cars)
and used by several of the big boat builders, ao MCY and Asym.

so the weight of the solid frame is well under controll

 

[rafiki_]

yes I would like exactly the same canvas & gliding system as on the pictures in post #680
this is made by Opac Mare (one of their departments that makes foldable roofs for cars)
and used by several of the big boat builders, ao MCY and Asym.

so the weight of the solid frame is well under controll

Thanks Bart, really nice. Sorry hadn't picked that up, getting late