Hard Top for Blue Angel (Canados 70s)

[grumpy_o_g]

a rough calculation (brother in law) tells me that a allum tube profile (as above) on 2 mounting points separated 4meter, with a weight in the middle of 100kg,
will bend 1cm, (chordal height)
but same size in GRP will bend double of that !
hmm, the bending / elasticity needs attention !

If GRP is too bendy then you could look at carbon fibre Bart (not Kevlar). It may start getting a bit expensive though as you will need somewhere with the skills and equipment to do this.

 

[BartW]

If GRP is too bendy then you could look at carbon fibre Bart (not Kevlar). It may start getting a bit expensive though as you will need somewhere with the skills and equipment to do this.

my feeling is (no real experience) that using carbon makes things unnecessary complex ( the process, find people to do it, ...)
so why not using Allum tube ?
I've seen that used by different manufacturers to reinforce certain area's of the deck's, or Flybridge overhangs, .. ?

 

[grumpy_o_g]

my feeling is (no real experience) that using carbon makes things unnecessary complex ( the process, find people to do it, ...)
so why not using Allum tube ?
I've seen that used by different manufacturers to reinforce certain area's of the deck's, or Flybridge overhangs, .. ?

No reason at all if you can make it rigid enough - I was making the wrong assumption that you were saying both aluminium tube and GRP were too bendy - my apologies.

 

[MrB]

I can't work it out from the pic but does this Canados 80 have a hard top? Looks quite good.

http://www.yachtworld.co.uk/boats/1997/Canados-80-2885267/Turkey#.VwVOeVQrLcs



Looks a similar setup to this Ferretti

http://www.yachtworld.co.uk/boats/2008/Ferretti-Yachts-780-2883470/Italy#.VwVQ1VQrLcs

 

[jfm]

The Canados ad is a typical "useless broker" advert. The interior is indeed a 1990s Canados 24m, and perfectly nice, but the main exterior picture is a completely different boat - a much newer Canados 86 from the last few years with a HT and not available at <0.5m euros

The ferretti looks good - if they could supply that HT to Bart as a spare part that would be great!

 

[MrB]

The ferretti looks good - if they could supply that HT to Bart as a spare part that would be great!

I was just searching boats and stumbled across it and thought of this thread. A page or two more and i spotted the Ferretti and it had a similar layout to Barts Canados. I posted because of your idea of retro-fitting a Fairline HT, maybe Bart could size up a Ferretti HT........would remove the pain and cost of developing a new mold.

 

[BartW]

we are seriously considering to incorperate a aluminium tube in the side profiles
fe tube with a rectangular cross section 100 x 60 x 2mm
aluminium is much stronger than GRP,
it allows us to make the rooftop sides small and slim, ....without worrying about strength,
we could even weld lateral beams between the side tubes on each end

but I'm wondering if there could be a problem with different lineair expansion coefficents;

lineair expansion coeff.
alluminium = 0.024 mm /m /°C
GRP = 0.030mm /m /°C

the difference with the stainless steel strip for the gliding mechanism is much bigger;
stainless steel = 0.016 mm/m/°C
so they must have thought about that,
I'll asc the supplier of the mechanism...

I believe that ao Fairline does something like this in their Flybridge overhang,
I'm wondering if the GRP goes simply over the bare aluminium profiles, or if they are painted / coated...

 

[jfm]

Bart, Fairline uses a lot of ali and bonds the GRP straight to it after the ali has first been bedded onto polyurethane, without any problem,. I therefore deduce that the difference in thermal expansion isn't significant. The polyurethane is flexible of course, but the GRP is then wrapped over the ali, so I doubt the polyurethane does anything useful for thermal expansion. So it should work fine for you

Fairline uses ali box section for fly overhang, decks generally, transom, and two big pillars where you installed acroprops in BA (because as you know there is a lot of weight at that point on a flyer beat with cantilevered overhang). Sun seeker use foam and GRP only, and I'm not sure about Princess. Ali box section obviously gives more strength and stiffness for a given kg, but is more expensive to build


Squadron 78 transom area (you can see the polyurethane glue in this shot)--->

Sq78 lower aft deck (passerelle tray on stbd side) --->

S78 fly deck, looking forward. The big ali box sections support overhang. Opening for flybr stairs (port side) is bottom right corner of picture. Incidentally, the centreline ali section at bottom of picture is designed to carry a spare prop shaft, accessed through a little hatch where the ensign is mounted. I don't carry a spare shaft, because I didn't want the weight of it up there --->

Fly deck, standing back looking from front to back. Virtually all the grid system you can see is ali box section, except the front 3 cheese shaped beams are grp on foam formers (yep Portofino, just foam!) --->

 

[vas]

Bart, Fairline uses a lot of ali and bonds the GRP straight to it after the ali has first been bedded onto polyurethane, without any problem,. I therefore deduce that the difference in thermal expansion isn't significant. The polyurethane is flexible of course, but the GRP is then wrapped over the ali, so I doubt the polyurethane does anything useful for thermal expansion. So it should work fine for you

Fairline uses ali box section for fly overhang, decks generally, transom, and two big pillars where you installed acroprops in BA (because as you know there is a lot of weight at that point on a flyer beat with cantilevered overhang). Sun seeker use foam and GRP only, and I'm not sure about Princess. Ali box section obviously gives more strength and stiffness for a given kg, but is more expensive to build


Squadron 78 transom area (you can see the polyurethane glue in this shot)--->

Sq78 lower aft deck (passerelle tray on stbd side) --->

S78 fly deck, looking forward. The big ali box sections support overhang. Opening for flybr stairs (port side) is bottom right corner of picture. Incidentally, the centreline ali section at bottom of picture is designed to carry a spare prop shaft, accessed through a little hatch where the ensign is mounted. I don't carry a spare shaft, because I didn't want the weight of it up there --->

Fly deck, standing back looking from front to back. Virtually all the grid system you can see is ali box section, except the front 3 cheese shaped beams are grp on foam formers (yep Portofino, just foam!) --->

John,

care to explain what's the polyurethene glue for in the first pic? is it to bed the aluminum section onto the grp or to keep the following layers of mat in close contact with the concave angles of the grp-al.box section? That is assuming you start the enclosing layup ASAP and with the glue still on!

I'm asking as I'm trying to figure a way of doing my h/t using foam slabs, timber reinforcements and wrap them all up in mat/epoxy (don't do grp I'm afraid...) worried on the concabe angles between the two from my experience on the much gentler angles of the chines (when I did wrap the hull of MiToS

cheers

V.

 

[jfm]

I really don't know Vas and never asked them. It is easier to lay/fold GRP into a corner if there is a gentle radius, but you can work ok with a sharp radius/angle. You need a gentle radius on an external/convex corner of course, but it is less critical on an internal/concave corner. In that photo it doesn't even look like they have dress the polyurethane glue into a gentle radius/filet, so I guess they don't need to. This is all chopped strand matt, which is more flexible and easier to work with in corners than your woven glass/epoxy

Dunno really. But I am pretty sure the thermal expansion difference isn't a problem!

 

[Portofino]

I,am still concerned that you will blow your diesel engines due to excess weight in a 80,s s designed boat .
here,s a copy of earlier post #29 -which nobody has commented on ?

If I can ask what rpm are you thinking of running -hoping to run and what is WOT ?
how about a simple lightweight carbon fibre bimini ,so light it simply attaches to existing frame and adds the weight of 1 or 2 extra (small) people only ?

post 29#
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 rebuilds -one a head gasket -over heat .
From memory you said in a previous post you need 2000 rpm -(WOT 2150 ish ? Real world ) ? plus more mid season fouling to plane at 20-22 knots cruise .
There is all ready some extra kg,s from previous modification -Hi Low platform .-stab + more ?

Its about higher than necessary piston velocity and old engines - IMHO not a good mix

http://mvdirona.com/TechnicalArticles/DieselEngineOverload/AvoidingDieselEngineOverload.htm

 

[BartW]

I,am still concerned that you will blow your diesel engines due to excess weight in a 80,s s designed boat .
here,s a copy of earlier post #29 -which nobody has commented on ?

If I can ask what rpm are you thinking of running -hoping to run and what is WOT ?
how about a simple lightweight carbon fibre bimini ,so light it simply attaches to existing frame and adds the weight of 1 or 2 extra (small) people only ?

post 29#
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 rebuilds -one a head gasket -over heat .
From memory you said in a previous post you need 2000 rpm -(WOT 2150 ish ? Real world ) ? plus more mid season fouling to plane at 20-22 knots cruise .
There is all ready some extra kg,s from previous modification -Hi Low platform .-stab + more ?

Its about higher than necessary piston velocity and old engines - IMHO not a good mix

http://mvdirona.com/TechnicalArticles/DieselEngineOverload/AvoidingDieselEngineOverload.htm

Hi Portofino,
thank you for your considerations,
Firstly I refer to my answer I gave on your post in my post #34:

......
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,

the boat has been tested at Full throttle 1.5y ago, (end of season) and still achieved 2300rpm max, even a little over,
that was with all the modifications, and scuba gear + compressors onboard, but low on fuel

we have recently done another mod, added bladder tanks cap 2000l in the bilges for extra fuel,
and beginning july plan is to fill her completely.
this will have a lot more impact on the weight / boat performance than a hardtop, or all mods we did so far.
we will closely monitor engines behaviour and at least not when completely full, drive her on 2000Rpm cruising speed,
(second rebuild engine only has 10 hrs on the counter )
so we will only gradually go up with RPM during the season.

we hardly ever drove the boat above 2000Rpm, and appart from a test (by the end of the season) I won't ever push her at 2300 or max RPM
we will threat this old lady very gently, and have no desire to go fast, contrary to you, owning a big beautifull sports cruiser !

 

[Portofino]

Hi Portofino,

we will threat this old lady very gently, and have no desire to go fast, contrary to you, owning a big beautifull sports cruiser !

Thanks for the answer Bart - hope it all works out well - and you should have have EGT to look at -seemingly a good tell tale of overloading @ near 2000 rpm ? in any ? -well thats what the link on overloading says.

Like you its not my intension to ever WOT or get near ,I find the sweat spot somewhere between 1600 to 1850 rpm ( right balance of speed /fuel consumption / ride ) .which gives plenty of headroom for mid /end of season fouling + full tanks etc.

I also have a % of load factor gauge too -think I only ever seen 95% @ 2250 rpm ,normally run @ 70-80 % at the above rpm mentioned .

interesting thread

 

[jfm]

Its about higher than necessary piston velocity and old engines - IMHO not a good mix[/url]

BTW, that parameter - piston speed - decreases as you load up the boat. You're better off measuring/managing other parameters if you want to avoid overload

 

[jfm]

I also have a % of load factor gauge too -think I only ever seen 95% @ 2250 rpm ,normally run @ 70-80 % at the above rpm mentioned .

That's a much more useful parameter and worth monitoring. Your numbers look good. "Load factor" is of course just jargon - what you are measuring is the time interval for which the injector is squirting fuel (upon the demand from the e-governor), as a % of the maximum value for that parameter set in the engine's ECU. That's a useful number

 

[Portofino]

I,am getting used to the boat at 1st I thought the MMDS was full of 4 screens of "crap" info compared to just water temp and oil pressure info VP gave me .

How ever -you know Germans + engineering -you gotta hand it to them starting to understand it all bit more , I think --and why they are telling us theses things

re Piston speed I was ref to rpm ie 2000 + over say 1850 they have to move and slowdown with more force at the higher rpm = more likely to knacker ,test the lub of the oil ,as well as thermal stress , all in an older engine .

 

[MapisM]

and you should have have EGT to look at

I don't think BA has any EGT gauge - surely that didn't come as standard with BA engines, anyway.
Out of curiosity, is that something you get out of your Böning displays, or was that an Itama add-on?
I would swear that even in more modern common rail MAN engines (I'm thinking of Deleted User boat, whose displays are also more modern than yours), there isn't the EGT in any screen - though I could be wrong.
Btw, according to a Cat brochure, also with their displays (MPD, as they call them), the EGT is only available when connected to the 3500 series engines.
With none of their 6L engines C9/12/18, and not even the C32 (jfm maybe can confirm or correct as appropriate), EGT is one of the number that you can get from their MPD.

 

[BartW]

I don't think BA has any EGT gauge - surely that didn't come as standard with BA engines, anyway.

no they don't , let alone that I would know what the normal specced temp is, or what is considdered as a max.

I'm about to order a pair new cooling water temp gauges for the engine room (the old mechanical "tubes" are broken)
does the forum think it is worth adding a pair of EGT gauges ?
at least I could get average data in normal conditions,
(also after reading info in that other thread regarding max engine RPM)

I don't intend to run the engines at 2000Rpm with the extra 2000l fuel onboard,
rather only when there is at least 3000l less

I can report that we ran the (rebuild) engines for a few minutes at 2000Rpm a few weeks ago, (after antifouling, and low on fuel and fresh water)
ofcause we have no objective indication of the "load" conditions, but everything behaved normal as before;
@ 2000Rpm, 20kn, cooling water 85°C, normal acceleration, no abnormal smoke,...
we didn't test full throttle yet

 

[jfm]

Yup mapism, cat c32 has no EGT. There are npt ports ready to fit a sensor if I want, and I'd use maretron sensors to feed the info to n2k, but I'm not convinced of the need and don't have time. I'd need 4 sensors and that is punchy amount of £££ because nothing about Maretron is cheap!

Anyway, % load factor gives me a good enough proxy. If the engines reach manufacture rpm with the boat loaded, which they do, and if that shows 100% load factor, then if I have about 70% load factor at 70% max rpm, I can conclude that EGT is likely ok. Conversely if the engines themselves are ok but 100% load factor produced 70% max rpm (=overloaded or over propped) there is something wrong, and I don't need to see an elevated EGT to know that. Happy to hear alternative theories but that's my off-the-cuff thinking

Good going Bart with the 2000litres extra. That's a substantial range increase - 140nm ballpark. Nice job

 

[Portofino]

I don't think BA has any EGT gauge - surely that didn't come as standard with BA engines, anyway.
Out of curiosity, is that something you get out of your Böning displays, or was that an Itama add-on?
I would swear that even in more modern common rail MAN engines (I'm thinking of Deleted User boat, whose displays are also more modern than yours), there isn't the EGT in any screen - though I could be wrong.
Btw, according to a Cat brochure, also with their displays (MPD, as they call them), the EGT is only available when connected to the 3500 series engines.
With none of their 6L engines C9/12/18, and not even the C32 (jfm maybe can confirm or correct as appropriate), EGT is one of the number that you can get from their MPD.

Da dah--- in order -3rd screen EGT ,4th "load"

It's just a bit over kinda max D speed starting to push a bow wave hence "loading "up .
Since found 825 rpm best Pootle -
Circa 2003 , -2876 le 401