Hard Top for Blue Angel (Canados 70s)

[MapisM]

Marriage is all about negotiation (well bribery actually)

LOL, reminds me of the old (allegedly) Chinese saying:
When you come back home from work, hit your wife a bit. You don't know the reason, but she does.
...I'll get my coat...

 

[jfm]

Bart,
Nice project. This will make BA perfect. Some quick thoughts:

1. I think the basic dimensions are ok, and the 500mm width of the side pieces on the underside is correct, but I would make it a bit thicker. It looks too thin in profile. Consider maybe a drop down 70mm lip to create an angle section. See this picture - you can see the lip around the edge because it is coloured silver:

2. Remember, the opening for the roof is smaller on the inside than the outside. Eg you might have a 5m L x 3.5m W canvas piece, but the opening viewed from beneath will be say 4m x 3.5m, because you need a ~1m shelf for the canvas part to sit on. This means you do not see the canvas when the roof is open, like picture above, and also this shelf adds nice stiffness to the whole structure. Here is a top view - the cardboard is on the "shelf":

And here is a finished top view - none of the canvas is visible from below because of the "shelf" concept:

3. The legs and the plates on them that you attach to BA need to be stiff and strong. I think you should have 2x 80mm dia tube legs at the front corners, welded to big plates. Here's a pic of my front leg components:

4. I would make the whole thing in GRP, from a plywood mould. Then you can create lots of funky shape details. You should be able to get the whole thing to 400kg including the legs and opening roof, which is fine on BA


5. Here are some detailed pics that might be generally helpful (note, the black canvas piece was temporary - they made me a silver one later and swapped it)

 

[vas]

3. The legs and the plates on them that you attach to BA need to be stiff and strong. I think you should have 2x 80mm dia tube legs at the front corners, welded to big plates. Here's a pic of my front leg components:

4. I would make the whole thing in GRP, from a plywood mould. Then you can create lots of funky shape details. You should be able to get the whole thing to 400kg including the legs and opening roof, which is fine on BA

Agree with 4 just want to comment on 3 J.

Bart's Canados superstructure is plywood, correct?
Creating mounting plates and just bolting them through a 12 or 15mm ply is not going to be enough as you know.
Bart, you have to remove all lining on the salon / galley not sure what's under the proposed legs area and figure out a way of reinforcing the area there.
Hence my idea of getting the mounts outside along the superstructure and being able to mount on two points, distribute the forces and get inner links/support from bulkheads that may be in suitable spots around the inside...

Having a big bugger 4mm steel plate to secure on the ply floor is not appealing to me at all unless it's massive enough to be fugly...
tbh, haven't found a solution to that yet (other than going sideways and avoiding mounting on the f/b floor.

cheers

V.

 

[jfm]

Yes, definitely Vas. BA's superstructure might need reinforcement on the inside, though it is possible that the plates at the bottom of the HT legs could be bolted right through some flybridge deck beams. I have no idea how the wooden part of BA is constructed, so BartW would need to analyse and comment

Also I expect the radar arch GRP legs on BA will need plenty of reinforcement on the inside. Inside my "shark fins" I have these bad boys made from 50x50 s/s thick walled box. (A bit over the top if you ask me!). The GRP sharkfins themselves are just yoghurt pot covers and they take no weight

A critical thing on BA is to anchor these to the flybridge deck so that the thing doesn't parallelogram athwartships. That is going to be a big challenge on BA. Ideally you want to make the legs L shaped, with the bottom of the L inside the boat attached along the length of a deck beam, or something

(on my boat the sharkfin legs pictured above stop fore-aft parallelograming, while the central A frame stops athwartships parallelogramming. This all has to be designing into BA, or the HT will wobble too much)

 

[vas]

Yes, definitely Vas. BA's superstructure might need reinforcement on the inside, though it is possible that the plates at the bottom of the HT legs could be bolted right through some flybridge deck beams. I have no idea how the wooden part of BA is constructed, so BartW would need to analyse and comment

Also I expect the radar arch GRP legs on BA will need plenty of reinforcement on the inside. Inside my "shark fins" I have these bad boys made from 50x50 s/s thick walled box. (A bit over the top if you ask me!). The GRP sharkfins themselves are just yoghurt pot covers and they take no weight

A critical thing on BA is to anchor these to the flybridge deck so that the thing doesn't parallelogram athwartships. That is going to be a big challenge on BA. Ideally you want to make the legs L shaped, with the bottom of the L inside the boat attached along the length of a deck beam, or something

John, if the various IT cantieri have some sort of consistency in the way they approached timber/ply construction, i'd expect to have a dense frame of 25X60 or even 30X80 for the 4m span and every 250 or 300mm, with a 15mm ply on top.
I'd either go through and distribute the forces further down the construction (lower deck or even down to some serious beams on the e/r!!!

Last pic shows nicely one of the most confusing issues you have to address on any hard top.
Lines of craft tapering upwards,
ppl moving without bumping their heads and shoulders on lower deck towards the bow
ppl on the f/b not bumping their heads on the H/T supports

Fairline did a v.nice job there, well done!

cheers

V.

 

[BartW]

The mounting of the legs is not a big issue I think,
because they can be placed on these side walls,
indeed these are wood, but they feel solid and strong, and the forces are spread over the complete wall.
underneath are the walls from the saloon,
inside these walls are solid tropical wooden beams.
plan is to make a acces opening / door in the zone where we want to place the legs, for inspecting and installing, ...

some more questions and comments on the above will come, but have to go now...

 

[BartW]

here a updated drawing

 

[Andrew M]

Looking great, I think it's going to be just superb. :encouragement:

 

[Portofino]

Hmm -dunno Bart ,
Boat looks great as is and was intended with fabric Bimini -there is something kinda "tropical " "bush camping " about taking shade under canvas IMHO .Also you can take it down / fold back at the edges of the season -All this is subjective
But fact is extra weight -do you really need it ?
Weight -I would offer up a contra view --- considering the engines have had recent rebulds -one a head gasket -over heat .
From memory you said in a previous post you need 2000 rpm -(WOT 2150 ish ? Realworld ) ? plus more mid season fouling to plane at 20-22 knots cruise .
There is allready some extra kg,s from previous modification -HiLow platform .-stab + more ?

Its about higher than neccessary piston velocity and old engines - IMHO not a good mix
( flak jacket on ready for Latestarter )

 

[jfm]

Bart, the sq78 hardtop is made at Greenland's factory in Slovenia, with vac infusion. Close to you in Montenegro. Why not buy one (thru fairline, because they own the mould tool) then get it delivered directly Slovenia - to Porto montengro with low VAT. Then you have a ready made opening-roof system all pre-engineered, and you just assemble it (the roof comes from 2 companies in UK - good guys). Then you modify your Canados shark fins to accept the HT, and you're all done for perhaps €30k

In the pic below I think I'm being faithful to the dimensions but I'm not 100% sure. Would need to check dimensions of course

 

[petem]

I like that JFM. Also worth bearing in mind that FL now offer a hard top for the SQ65 which I assume is a little smaller.

 

[BartW]

John, thanks for the pics,
You have been doing and closely following a very similar project, so your advice is welcome and much appreciated!
Thanks to all other aswell for contructive and or critical advice.
Thanks a lot !
Here are a few questions,

1) You sugest to make the frame “thikker”, 70mm lip… is this for esthetics only or also for strength ?
remember I prefer a “ slim” design, thicker is of course doable but prefer thinner if that is strong enough.

2) I noticed that “shelf” on your and others hardtops, for me this is not really necessary, (ea easy acces to all parts of the gliding system, etc… ) I don’t mind seeing the underside of the canvas. But indeed strength is a good reason to have it
Don’t you have / didn’t they offer you the lifter option for the canvas ? you probably don’t need this when you have that shelf.
I think that I am going to have the lifter option anyway, and have that shelf only if I need more strength after everything is assembled (in the workshop)
With the lifter option the folded canvas looks very neat iirc

3) The construction method is my biggest issue, agree that overall GRP is the best, very little experience on that, so many questions,;

3.1 plywood mould, positive or negative ?
3.2 for practical reasons I’m thinking of making the frame in three main parts; one front part , and 2 side parts bolted on the sides of the front part (and perhaps some extra items such as that shelf, and a mating part to the radar arch)
3.3 My mate / carpenter could make the mould in my worshop, I have a friend in Goes with some pro GRP expertise OR I have got info from a specialized co in UK (with experience on hardtops).
any other options / opinions, advice for how / by whom to make the GRP construction
also final assembly and full testing can be done in my workshop, we have the space for this.
3.4 some people sugest Carbon fibre, I like the look of carbon fibre, could use this as finishing color for the hardtop, can CF be used as alternative for glass mat ? or would this complicate things unnecessary
3.5 what thickness would the GRP layup need to be , for some parts we need a double shell one top and one bottom ?
Would be good to have a few dimensions (of the side sections) and GRP thickness of Match’s hardtop, as a reference.

3.6 Also I’m interested to know how much the canvas frames are “curved” how many centimeters higher are the bars in the middle compared to the sides ?
I know we need some curvation for water drainage, but I prefer not too much. On Match it looks very good, nearly flat, ….

For this project I need more help then ever before
Thanks again for advice,

 

[P4Paul]

John, thanks for the pics,
You have been doing and closely following a very similar project, so your advice is welcome and much appreciated!
Thanks to all other aswell for contructive and or critical advice.
Thanks a lot !
Here are a few questions,

1) You sugest to make the frame “thikker”, 70mm lip… is this for esthetics only or also for strength ?
remember I prefer a “ slim” design, thicker is of course doable but prefer thinner if that is strong enough.

2) I noticed that “shelf” on your and others hardtops, for me this is not really necessary, (ea easy acces to all parts of the gliding system, etc… ) I don’t mind seeing the underside of the canvas. But indeed strength is a good reason to have it
Don’t you have / didn’t they offer you the lifter option for the canvas ? you probably don’t need this when you have that shelf.
I think that I am going to have the lifter option anyway, and have that shelf only if I need more strength after everything is assembled (in the workshop)
With the lifter option the folded canvas looks very neat iirc

3) The construction method is my biggest issue, agree that overall GRP is the best, very little experience on that, so many questions,;

3.1 plywood mould, positive or negative ?
3.2 for practical reasons I’m thinking of making the frame in three main parts; one front part , and 2 side parts bolted on the sides of the front part (and perhaps some extra items such as that shelf, and a mating part to the radar arch)
3.3 My mate / carpenter could make the mould in my worshop, I have a friend in Goes with some pro GRP expertise OR I have got info from a specialized co in UK (with experience on hardtops).
any other options / opinions, advice for how / by whom to make the GRP construction
also final assembly and full testing can be done in my workshop, we have the space for this.
3.4 some people sugest Carbon fibre, I like the look of carbon fibre, could use this as finishing color for the hardtop, can CF be used as alternative for glass mat ? or would this complicate things unnecessary
3.5 what thickness would the GRP layup need to be , for some parts we need a double shell one top and one bottom ?
Would be good to have a few dimensions (of the side sections) and GRP thickness of Match’s hardtop, as a reference.

3.6 Also I’m interested to know how much the canvas frames are “curved” how many centimeters higher are the bars in the middle compared to the sides ?
I know we need some curvation for water drainage, but I prefer not too much. On Match it looks very good, nearly flat, ….

For this project I need more help then ever before
Thanks again for advice,

My thoughts on some of your questions.

3.1. I personally would want a moulded finish on both the topside and underside, to do this you would need to either make an enclosed mould with shut lines/splits to enable layup and extraction, or, make two moulds, one inner, one outer and then stick the two skins together while still in the moulds. Personally I prefer enclosed moulds but it is the harder and more time consuming of the two options.
3.2. I agree, and gives you the choice of either bolting together or stitching together with GRP when assembling the whole roof.
3.3. If you design with manufacture in mind then the actual GRP manufacturing will not be too hard. The magic is in making the tooling!
3.4. Carbon would be an option, but it will come at a cost and mean the tooling needs building with vacuum bagging in mind. If you want to leave the carbon exposed then you need to protect it from uv light or else it will yellow quite quickly. Getting a perfect finish with wet lay carbon fibre is a real art, that's is why most CF products made to be viewed are produced from pre-preg but if you want to use pre-preg your costs will go through the roof and you will need an autoclave or large oven.
3.5. A hard question to answer without looking at the final drawings in detail. The more shape you design in, the less GRP you will need to load into the build. A flat panel is a nightmare both in terms of strength and rigidity and needs to sit in the moulds until fully cured to stop it warping. Inner and outer mouldings stuck together allow lots of monoque shape to be introduced which significantly reduces the need for bulk. The side panels would need to hide a void to carry cables etc to the roof so it is not all about the thickness of the layup.
3.6. I would incorporate a gutter or channel in the hardtop to drain away water rather than let it run over the sides of the hardtop. So the soft top curve could be optically hidden as I expect it is on Match, but I am guessing.

Hope this helps, looks like a great project although I suspect the engineering will be less challenging than perfecting the design!

Paul.

 

[BartW]

Hmm -dunno Bart ,
Boat looks great as is and was intended with fabric Bimini -there is something kinda "tropical " "bush camping " about taking shade under canvas IMHO .Also you can take it down / fold back at the edges of the season -All this is subjective
But fact is extra weight -do you really need it ?
Weight -I would offer up a contra view --- considering the engines have had recent rebulds -one a head gasket -over heat .
From memory you said in a previous post you need 2000 rpm -(WOT 2150 ish ? Realworld ) ? plus more mid season fouling to plane at 20-22 knots cruise .
There is allready some extra kg,s from previous modification -HiLow platform .-stab + more ?

Its about higher than neccessary piston velocity and old engines - IMHO not a good mix
( flak jacket on ready for Latestarter )

hi, thanks for the compliment on the boat
bimina has been discussed long ago in another thread, but here I explain again, also for others:

we have been looking at the bimini option, over the helm station,
and seriously considered again a few months ago !,
but issues are:
- I want a permanent roof / canvas over the helm station, while the rear bimini is folded, but none of the dual bimini's looks nice
- The hardtop enables to fit curtains for winter protection and extra dry space on the FB

extra weigh, I really don't care, and don't believe the HT has much influence on the engines regime,
anyway, even with loads of extra mods, and loads of diving stuff onboard (could take that off if I want)
the engine regime is still very good, nominal 2000rpm giving 20..21kn cruising speed,
I hardly ever go over 2000 rpm, and use her a lot at 1100 RPM
(Full throttle is 2300 rpm as you know)
engines are both "nearly" new,

 

[BartW]

Bart, the sq78 hardtop is made at Greenland's factory in Slovenia, with vac infusion. Close to you in Montenegro. Why not buy one (thru fairline, because they own the mould tool) then get it delivered directly Slovenia - to Porto montengro with low VAT. Then you have a ready made opening-roof system all pre-engineered, and you just assemble it (the roof comes from 2 companies in UK - good guys). Then you modify your Canados shark fins to accept the HT, and you're all done for perhaps €30k

In the pic below I think I'm being faithful to the dimensions but I'm not 100% sure. Would need to check dimensions of course

thanks for the idea and the drawing
that is ofcourse a possible option, but you know my problem with this J,
the shape is not perfectly as I have it in my mind so rather try to look for another solution:

- I prefer a permanent "roof" above the helm station and E wants the opening zone as large as possible,
both features not the case with your hardtop

- the FL hardtop is a bit more bulky, fatter shape, its part of the SQ78 design, (in my eyes)
I prefer a more slim, more minimalistic shape.
(tbh I'm still looking at the perfect match of the HT and the radar arch, fe sharkfin collor also black, ....)

- the lines are not completely matching the straight lines from this old Canados...

Vat is no issue its all on a company...
Montenegro border IS a issue, need to export / import such a big item,
I'm thinking / considering mounting the hardtop in Croatia or Italy, ....
would be a nice project to pre-assemble and test in my company here in Belgium

 

[BartW]

3.1. I personally would want a moulded finish on both the topside and underside, to do this you would need to either make an enclosed mould with shut lines/splits to enable layup and extraction, or, make two moulds, one inner, one outer and then stick the two skins together while still in the moulds. Personally I prefer enclosed moulds but it is the harder and more time consuming of the two options.

actually I believe that some parts of the underside of a MCY hardtop don't have a moulded finish, but a more rough finish, (black like mine)
and I have to confess that I like that.
but anyway it seems not too difficult to mould a extra "bottom pannel" and stick them together

thanks for sharing your thoughts and your answers

 

[jfm]

John, thanks for the pics,
You have been doing and closely following a very similar project, so your advice is welcome and much appreciated!
Thanks to all other aswell for contructive and or critical advice.
Thanks a lot !
Here are a few questions,

1) You sugest to make the frame “thikker”, 70mm lip… is this for esthetics only or also for strength ?
remember I prefer a “ slim” design, thicker is of course doable but prefer thinner if that is strong enough.

2) I noticed that “shelf” on your and others hardtops, for me this is not really necessary, (ea easy acces to all parts of the gliding system, etc… ) I don’t mind seeing the underside of the canvas. But indeed strength is a good reason to have it
Don’t you have / didn’t they offer you the lifter option for the canvas ? you probably don’t need this when you have that shelf.
I think that I am going to have the lifter option anyway, and have that shelf only if I need more strength after everything is assembled (in the workshop)
With the lifter option the folded canvas looks very neat iirc

3) The construction method is my biggest issue, agree that overall GRP is the best, very little experience on that, so many questions,;

3.1 plywood mould, positive or negative ?
3.2 for practical reasons I’m thinking of making the frame in three main parts; one front part , and 2 side parts bolted on the sides of the front part (and perhaps some extra items such as that shelf, and a mating part to the radar arch)
3.3 My mate / carpenter could make the mould in my worshop, I have a friend in Goes with some pro GRP expertise OR I have got info from a specialized co in UK (with experience on hardtops).
any other options / opinions, advice for how / by whom to make the GRP construction
also final assembly and full testing can be done in my workshop, we have the space for this.
3.4 some people sugest Carbon fibre, I like the look of carbon fibre, could use this as finishing color for the hardtop, can CF be used as alternative for glass mat ? or would this complicate things unnecessary
3.5 what thickness would the GRP layup need to be , for some parts we need a double shell one top and one bottom ?
Would be good to have a few dimensions (of the side sections) and GRP thickness of Match’s hardtop, as a reference.

3.6 Also I’m interested to know how much the canvas frames are “curved” how many centimeters higher are the bars in the middle compared to the sides ?
I know we need some curvation for water drainage, but I prefer not too much. On Match it looks very good, nearly flat, ….

For this project I need more help then ever before
Thanks again for advice,

Hi Bart
Yes I can sympathise with your comments that the sq78 ht isn't a perfect partner for the canados lines. It was just a wild idea. Having the roof and water drains all ready-designed would be nice, but let's move on to your custom design

1. I was thinking strength and stiffness. A span of 5m with a 500m width is going to flex a lot unless you get say 200mm of height. I realise you want a slim look of course. But if the thing flexes then the roof will not slide smoothly

2. The lifter mechanism only works on the top canvas. Unless you are happy to look at s/s bars you need an inside fabric liner too, like the inside roof of a car. That has no lifter so it goes all floppy. Thr shelf hides that.

I have lifters so make the canvas zig zag neatly. I also have a really clever system for the inner lining fabric ( the car headliner part): as the roof slides open the tension is taken out of the inner liner section by section. So when roof is half open, the half of the liner you can still see remains tight. It only goes floppy above the shelf, where you can't see it. This is a really slick mechanism

3.1. I was thinking negative mould. Mdf, spray painted mould. One-time use only allows you to make return faces easily at the sides without having to worry about releasing it ( you just break thr mould). Then you can line thr solid roof with plastic plywood panels wrapped in white vinyl. That avoids making a fibreglass mould for the big soffit face. Hard to describe in a post. Better to sketch on paper. Paul gives better advice than I can on grp. I think grp not carbon, with foam coring (eg airex or divinycell)

3.2. Yes making in sections is ok but you have to get great corner stiffness. If the roof opening becomes a parallelogram the roof mechanism will jam. The shelf makes a huge contribution to the roof opening remaining a perfect rectangle. (I like the shelf! Also it gives you more non canvas area for down lights and speakers. The uber quality lighting is one of the nice benefits of a HT)

3.3. See Paul's post

3.4. Grp not carbon IMHO. You don't care about 100kg of weight saving. The Grp needs to be cored, but that's ok.

3.5. How long is piece of string?! If you get curvature, coring and rib sections in thr design the grp will mostly be thin, like 5mm thick or 3x1.5 oz layers

3.6. I'll measure. The curve is slight, maybe 40mm chordal height only. That's enough for water drainage. You need a gutter plus drain piping. Mine has plastic water drain pipe inside the. 80mm dia support legs

I'll get you some dimensions...

Interesting project. Very challenging to get it slick and professional looking, as I know you will want it. Good luck!

 

[BartW]

I also have a really clever system for the inner lining fabric ( the car headliner part): as the roof slides open the tension is taken out of the inner liner section by section. So when roof is half open, the half of the liner you can still see remains tight. It only goes floppy above the shelf, where you can't see it. This is a really slick mechanism

Yes I know the system, its this model that I have in mind to use




re. parallelogramming of the frame;
I believe that fixing against the radar arch (really solid!)
is a good base for avoiding (partially) parallelogramming...
only need some solid legs in the front,

 

[vas]

re. parallelogramming of the frame;
I believe that fixing against the radar arch (really solid!)
is a good base for avoiding (partially) parallelogramming...
only need some solid legs in the front,

which along 5m length is almost impossible to achieve Bart!
It's all too easy for the front to fish around 30-40mm flexing the tubular front columns (or their mounting and side walls of the f/b).
There wont be any cross bracing, so I'd agree with John that you really need the shelf.
How about swapping the mechanism around and have the shelf on the front with the tent collected by the helm, justifying and not increasing your fixed hardtop over the helm seating?
That may sort out both the orthogonality of the frame and the large opening over the rest of the f/b that E wants

cheers

V.

 

[BartW]

How about swapping the mechanism around and have the shelf on the front with the tent collected by the helm, justifying and not increasing your fixed hardtop over the helm seating?
That may sort out both the orthogonality of the frame and the large opening over the rest of the f/b that E wants

V.

that was the plan from the start Vas, probably didn't explain very well,
but yes I agree, the shelf does a big contribution to the orthogonal strength
moreover the "free" length of the side members of the frame is than reduced from approx 5m to 4m.

In the initial drawing the width of the sides is only 300mm (instead of 500mm as mentioned by Jfm)
but I agree we need to make this really strong, and think carefully about the layup and profile of that section