Hard Top for Blue Angel (Canados 70s)

[BartW]

Project has been discussed 2 years ago,
http://www.ybw.com/forums/showthrea...-70s)-Rebuild-thread/page68&highlight=hardtop
from post #680

And is back on the table right now.
I’m not in a hurry to have it finished before the coming season but we ‘ll see what happens

This is a scetch as I have this hardtop in mind;

Key features:

Total surface approx 6m x 4m (L x W)
Motorized Gliding system for the opening roof, as big as possible, approx. 5m x 4m
The first 1m doesn’t open, it’s a fixed roof above the helm station

The side profiles are as slim and small as possible ( looking nice and slim, but enough strength)
The hardtop stops against the radar arch,
the gliding roof “nose” kisses or closes against the existing radar arch.
The frame should have a luff track so that in future we can have canvas curtains with windows for winter protection of the FB

I have 2 proposals for a gliding system, and this looks really feasible (more about that later)

We need to design this hardtop / frame.
And there are a few questions to solve
Actually this project seems more complicated than a few other more major upgrades we did ;-)

1) How to construct this hardtop frame,
initial idea was plywood covered with glass mat and epoxy, but I know that GRP is the right way to do this.
I have no experience with that, so that brings me to 2 more questions:
2) How to make this strong enough to cope with wind / storm, but not too heavy….
the right size and shape for the side profile / frame
3) I want a dark finish, (dark silver grey or carbon color) how is this finish going to react to sunlight,
how about thermal expansion / bending of the hardtop frame ?
More questions about some detais will come later

Here is a very preliminary scetch, don’t pay attention at the details , the drawing is made by a colleague in the office while I am in another country / communication by Iphone…
and with a plywood construction in mind, But due to Vas’s hardtop thread I had the urge to start this thread without further delay
and Jfm already convinced me to drop the plywood solution
De drawing will be updated with more exact dimension when I’m at the boat in 2 weeks

 

[rafiki_]

Looking forward to these developments Bart. Have you discounted using carbon fibre to reduce weight and improve strength? If you are laying up by hand over a low cost mould, then not more difficult than grp. I think it would need curing in an autoclave, and one of your local Universities might have one, and might be willing to take the hardtop on as a final year student project?

 

[MapisM]

Niiiiice! :encouragement:
I'm sure it'll look beautiful on BA, and will add a lot of value/usability.
With regard to construction, the very same suggestion that rafiki made popped to my mind while reading your post, and before reading his.
Strength is in fact very important with such large windage, as is weight, obviously.
To support it in the forward section, you are thinking to use steel poles, I suppose?
I see a rather thin one in your pic, with approximately the same angle as the radar arch.
'Fiuaskme, I'd rather make the poles straight/vertical, and I would NOT try to "hide" them by using a small diameter - rather the opposite, in fact.
Looking fwd to a very interesting thread, anyway!

 

[vas]

will try to reply at length in the evening as I'm between meetings atm...

Bart, before showing us 1:5 details, maybe discuss the whole construction a bit more?

I like the shape, I fail to see the support mid and front and I need to know materials used and sizes.
I very much doubt you're going to get away with such thin construction side beam over 6M length!

I'm getting close to finilising (er, almost) the structural frame for my 2X2.4m hardtop and It feels like 60mm dia poles on each side and 70-80mm cross section coldformed ss plates will be used to give necessary rigidity.

FWIW, I've scrapped the timber/grp/epoxy options so I'm going for a quasi-spaceframe with a combo of tubular (probably 30-35mm dia) and coldformed ss sections where the two solar panels will be mounted and where the 4 supports will be welded securely.
Probably will need half a sq. metre of skining on this thing, mostlikely candidate is the sandwitch panel alloy/rubber/alloy 3mm thick I used for lining the aft deck area (if I don't decide to do it all SS and be done with!)
I'm struggling with the roof lining of the thing though!

some sketches later

cheers

V.

PS. looks v.nice and slim! Maybe a tad too nice to be feasible though

 

[Deleted User YDKXO]

I don't know that grp is the right way to go. I never like the idea of adding extra weight high up on any boat and this seems like a substantial structure you want. How about using anodised aluminium instead which will be much lighter http://www.atlantictowers.com/hiline.php

I may be wrong but I believe that some of the Dutch steel boat yards use aluminium for some structures on board. May be worth trying to find out if there is a custom aluminium fabricator in Holland who could make such a hardtop

 

[Pinnacle]

Bart

Does E approve?

 

[BartW]

Have you discounted using carbon fibre to reduce weight and improve strength?

carbon fibre would be perfect, only problem is that I don't know nothing, nor know someone with experince, to do the work...

 

[BartW]

To support it in the forward section, you are thinking to use steel poles, I suppose?
I see a rather thin one in your pic, with approximately the same angle as the radar arch.

its a older drawing, have to make a update,
with 2 x vertical poles on each side, near the helm position,
and one short 45° pole, fixation on the radar arch,
all at least 60mm diameter,

 

[BartW]

How about using anodised aluminium instead which will be much lighter[/URL]

have been thinking about aluminium, big advantage is that the bending and welding we can do in my company (not the lazer cutting, but that is easy)
but main concern is corrosion on long term.
my side deck, and transom telescopic doors are alluminium,
even with the best painting corrosion is a issue

 

[BartW]

Bart

Does E approve?

yes, finally after long and hard negotiations

 

[jrudge]

have been thinking about aluminium, big advantage is that the bending and welding we can do in my company (not the lazer cutting, but that is easy)
but main concern is corrosion on long term.
my side deck, and transom telescopic doors are alluminium,
even with the best painting corrosion is a issue

Paint with a wrap on top with intentionally over lapping seams to make it more water tight?

The wrap would certainly keep the general water / salt off it, and also provide the black colour you are seeking.

 

[Pinnacle]

yes, finally after long and hard negotiations

You must give some lessons......................

 

[Deleted User YDKXO]

even with the best painting corrosion is a issue

Agreed, potentially in the long term but it is the long term if you protect it correctly as jrudge suggests. Just FYI the Steeler 46 mentioned here http://www.ybw.com/forums/showthread.php?451448-Mystery-explained has an aluminium hardtop and indeed some Dutch steelboat builders do make complete boats out of aluminium so they must be confident that their protective systems are robust

 

[BartW]

Paint with a wrap on top with intentionally over lapping seams to make it more water tight?

The wrap would certainly keep the general water / salt off it, and also provide the black colour you are seeking.

really good idea,

the big advantage of aluminium is that we can build en modify and rebuild, until we have the perfect and complete assembly, including fixing the gliding system and its accesories, and the poles and all the bits and pieces, ....
and only then disassemble and paint the frame, and put a extra protective wrap on the outside surface...

this building method looks very interesting because its more easy to manage I think.
the light weight is a good additional extra aswell

 

[Deleted User YDKXO]

the big advantage of aluminium is that we can build en modify and rebuild, until we have the perfect and complete assembly, including fixing the gliding system and its accesories, and the poles and all the bits and pieces, ....
and only then disassemble and paint the frame, and put a extra protective wrap on the outside surface...

Yes and even better this means you can hide the price from the SWMBO. No incriminating and embarrassing invoices hanging about that will cost you a new kitchen

 

[MapisM]

LOL, obviously you have never seen BA galley, M.
Actually, I can't think of any aspects of BA that Ms. BartW can complain about.
But pretty sure the galley is not one of them!

 

[Pinnacle]

LOL, obviously you have never seen BA galley, M.
Actually, I can't think of any aspects of BA that Ms. BartW can complain about.
But pretty sure the galley is not one of them!

Actually P, I think Deleted User was referring to the kitchen at home. Somewhat of a more expensive exercise than a galley on a boat. (I speak from experience! )

 

[Deleted User YDKXO]

Actually P, I think Deleted User was referring to the kitchen at home. Somewhat of a more expensive exercise than a galley on a boat. (I speak from experience! )

Yup thats right. A major expenditure on my boat often results in a quid pro quo expenditure on our house. Marriage is all about negotiation (well bribery actually)

 

[P4Paul]

Looking forward to these developments Bart. Have you discounted using carbon fibre to reduce weight and improve strength? If you are laying up by hand over a low cost mould, then not more difficult than grp. I think it would need curing in an autoclave, and one of your local Universities might have one, and might be willing to take the hardtop on as a final year student project?

If you want to autoclave then you should forget the words 'low cost mould'...

Wet layup carbon fibre under vacuum would be fine.

 

[MapisM]

Actually P, I think Deleted User was referring to the kitchen at home.

Doh! I should have thought that no EN mother tongue speaker (as opposed to myself!) would have used the term kitchen for a boat...