Fairline Squadron 78 refit/fit - Hard Top

[Hurricane]

Could you post/comment on the process of teak sanding.
Are you removing any of the deck fittings when sanding? etc...

 

[MapisM]

The stabiliser job has turned into a refit of the actuator assembly not just the fin, so Sleipner can fit their new keyless tapered shafts.

Interesting stuff, but doesn't that sound like a solution to a non existing problem?
I mean, what's wrong with the the simpler shafts that always worked just fine on any boat - for almost 20 years now on mine, just as an example...?
Besides, IIRC you had the same fins size (1sqm) also with the flat ones, didn't you?
I'm asking because according to the claims of higher efficiency AOTBE, I expected that you were fitting somewhat smaller fins.
The underlying assumption being (obviously) that the smaller any bits sticking out of the hull are, the better, particularly on a P hull, but also in general.

As an aside, I fully agree that - for what can be seen in your pics - the GRP plugs look perfect. A grp hull can't get any better! :encouragement:

 

[jfm]

Interesting stuff, but doesn't that sound like a solution to a non existing problem?
I mean, what's wrong with the the simpler shafts that always worked just fine on any boat - for almost 20 years now on mine, just as an example...?
Besides, IIRC you had the same fins size (1sqm) also with the flat ones, didn't you?
I'm asking because according to the claims of higher efficiency AOTBE, I expected that you were fitting somewhat smaller fins.
The underlying assumption being (obviously) that the smaller any bits sticking out of the hull are, the better, particularly on a P hull, but also in general.

As an aside, I fully agree that - for what can be seen in your pics - the GRP plugs look perfect. A grp hull can't get any better! :encouragement:

Hi MapisM. I can't justify any of it on need (!) so my rationale is just that I'm interested to have the latest and greatest gear really. The simpler keyed shafts do the job though they can be a PITA to remove and I bet you would have some fun trying to remove yours after 20 years - when the female taper is encased inside a composite fin you cannot heat it up as you can with a propeller hub. So yes it is a solution to a non existent problem but that's nothing new as regards most boats/my boat

Yes I previously had 1.0 sq m flat fins and am switching to 1.0 curved. Because of the higher effectiveness of the curved fin I could have fitted say 0.7m sq rather than 1.0m sq and got broadly the same performance in theory. Several of the retrofitted Sq78 stabilisers installations do exactly that, because the 0.7 has a smaller actuator, which is easier to retrofit obviously. I have the bigger actuators though and I decided to stick with 1.0 in order to get even more performance at anchor. At D speed there will be extra drag but Sleipner have a hunch that the lift from the big curved fin will "pay" for the extra drag at P speed by making the boat semi-hydrofoil. We might want more stern lift too and if that's the case I have the option to install bigger flaps (because I already have upgraded flap hydraulics, installed during build) or just add some Interceptors. Or even a pair of fixed interceptor blades. All this is unproven so I do not know if any of it will work - have to find out by trial and error. It's easy (with hydraulic taper LOL!) to fit 0.7m sq fins if all the above theory/hunch turns out to be wrong, but it's nice to experiment. As you know I have very accurate fuel flow measurement and litre-per-mile measurement so I should be able to see quickly whether I'm barking up the right or wrong tree. Stay tuned!

 

[jfm]

Could you post/comment on the process of teak sanding.
Are you removing any of the deck fittings when sanding? etc...

Hi Hurricane. The s/s fittings are being double masking taped, not removed (I didn't want the damage of removing them). The guy is using a 150mm diameter orbital sander, but as he approaches a s/s fitting he switches to a mouse sander and/or hand sanding

Where the deck meets GRP side coaming, superstructure, bulkwarks or any vertical "wall", he just uses a piece of 3mm MDF, about 500mm long by 100mm tall and places it on its edge against the GRP. The sander then just rubs up to the MDF which protects the GRP. He actually masking tapes the GRP too, just for nice OCD ness

The caulking was 0.5mm proud where the deck was in the sun a lot. This is the new teak deck doing its initial shrink down to a steady state, where I think it will stay for several years without further significant shrinkage. The proud caulking was knifed off using one of those little handles that you slip a Stanley knife blade into, converting the blade into a sort of scraper/chisel. Removing the proud caulking was like a hot knife thru butter

The honey colour of the teak comes very quickly - as you know the grey layer is perhaps 0.1mm thick only. I'll post pics

My overall theory here is to sand the decks once, at about 18months old, to level them after the initial shrink down of the wood. I'm taking about sanding off perhaps 0.2mm off 6mm thick teak. I don't then plan to sand them every year. My thinking is they will now go several years with no additional sanding, and just cleaning

 

[Hurricane]

Hi Hurricane. The s/s fittings are being double masking taped, not removed (I didn't want the damage of removing them). The guy is using a 150mm diameter orbital sander, but as he approaches a s/s fitting he switches to a mouse sander and/or hand sanding

Where the deck meets GRP side coaming, superstructure, bulkwarks or any vertical "wall", he just uses a piece of 3mm MDF, about 500mm long by 100mm tall and places it on its edge against the GRP. The sander then just rubs up to the MDF which protects the GRP. He actually masking tapes the GRP too, just for nice OCD ness

The caulking was 0.5mm proud where the deck was in the sun a lot. This is the new teak deck doing its initial shrink down to a steady state, where I think it will stay for several years without further significant shrinkage. The proud caulking was knifed off using one of those little handles that you slip a Stanley knife blade into, converting the blade into a sort of scraper/chisel. Removing the proud caulking was like a hot knife thru butter

The honey colour of the teak comes very quickly - as you know the grey layer is perhaps 0.1mm thick only. I'll post pics

My overall theory here is to sand the decks once, at about 18months old, to level them after the initial shrink down of the wood. I'm taking about sanding off perhaps 0.2mm off 6mm thick teak. I don't then plan to sand them every year. My thinking is they will now go several years with no additional sanding, and just cleaning

Thanks for that
Mine needs some attention and I'm wondering what to do.
Even thought of replacing it with synthetic.
I like it looking like new (honey colour) - I don't like the silver finish that the yachties seem to crave for.
My caulking is very much proud of the surface, maybe I will have a go with the Stanley knife idea.

 

[Nick_H]

Thanks for that
Mine needs some attention and I'm wondering what to do.
Even thought of replacing it with synthetic.
I like it looking like new (honey colour) - I don't like the silver finish that the yachties seem to crave for.
My caulking is very much proud of the surface, maybe I will have a go with the Stanley knife idea.

I did all my caulking with a very sharp chisel, and it's a lovely job, really therapeutic! I managed to get a couple of continuous bits of shaved caulking the entire length of the flybridge

It's not quite up there with chopping up logs with a chainsaw, which is about as good as it gets, but it's definitely one of the nicest jobs I've done on a boat. If your boat was in Lymington I'd do it for free

 

[ICTM]

I did all my caulking with a very sharp chisel, and it's a lovely job, really therapeutic! I managed to get a couple of continuous bits of shaved caulking the entire length of the flybridge

It's not quite up there with chopping up logs with a chainsaw, which is about as good as it gets, but it's definitely one of the nicest jobs I've done on a boat. If your boat was in Lymington I'd do it for free

Mine is in Beaulieu, is that close enough !!

Sorry for the drift JFM 

 

[Nick_H]

Mine is in Beaulieu, is that close enough !!

Sorry for the drift JFM 

Ha, I think I may have been a bit rash with that offer!

Seriously though, it's neither a skilled nor a difficult job, and you get instant gratification because the decks immediately look loads better. Just make sure the chisel is razor sharp and it really is, as jfm said, like a hot knife through butter.

 

[MapisM]

So yes it is a solution to a non existent problem but that's nothing new as regards most boats/my boat

Haha, good point. Pretty much the same as the (albeit increasingly popular, I must admit!) AnCam....?
Running for cover now...

 

[alt]

jfm - I haven't read the above posts much as i'm just breezing though, but did you mention sanding teak that has some proud caulking? I have the same issue.

Can you ask your guy if the caulking can be sanded OK? And what grade sandpaper should be used? I understand in the corners it will probably need to be hand-sanded, or mouse sander, and to use MDF along the edges (good tip) with GRP

 

[BartW]

All very interesting J, thanks for sharing.

Re. Hardtop,
Looks very nice, and as a integrated part of the SQ78
I have to admid that I was a bit sceptic after seeing some first pics, but now on Match, from different vieuw points it looks very nice. The silver and black are perfect.
I still think that the height should be a bit lower, can you measure the height from FB floor until below the rooftop ?
Thanks for explaining the details on the drainage of the rain water, all very interesting, but now I’m hesitating to continue with my own hardtop project, as it is all much more complicated than I thought. I’m mostly afraid about the weight versus strength, more later in my own thread.

Re. Fins, I was waiting to hear what size of curved fins you were going to fit, you know this 
but you explained to MapisM, all clear.
I’m a bit sceptic about “lift” by fins or flaps, and lowering fuel consumption, but that’s all intuitive, so really interested in your test results, I know you will have accurate measurements for comparison. Just for the test it would be interesting to know if or by what % you would decrease the consumption with 0.7sq fins.
With the 1sqm curved fins, and the extra stabilizing capacity, you will have the most stable 80ft boat at anchor, on the planet 
All very interesting stuff !

Re hull thickness,
These cutouts are a objective proof of a very well build hull,
These are details that you can almost never see on any yacht,
sometimes people have a opinion about how good a boat is build, without objective arguments.
This is real proof, very good !

Re teak sanding,
All agreed,
Its amazing, 3 years after we have recaulked and sanded the teak,
How much this is worn out again, especially on the bow area, exposed to the elements permanently.
I’m afraid that re-sanding is needed every 3 to 4 year. But by than I'm quite sure that Match II will have a new owner ;-)

Railcapping varnish; what type of varnish are you using ?
We have used slow drying oil based Epiphanes varnish, also for re-varnishing, (typical for Teak wood)
But due to the moisture at nigh (in winter) the result is not good,
We have to sand at least that new layer, and re- varnish, when climate and temp is better.
This is a never ending story on BA

Re Ancam,
MapisM we have to disagree on this one,
Our Ancam is in the most perfect position, as if you are standing on the bow, and looking forward right down to the anker and the chain.
This is absolutely a practical solution for a real problem, more on that later in one of my own threads,
MapisM There is only one way to convince yourself how practical this is, and that is to come again onboard of BA and experience this huge practical benefit yourself


 

[MapisM]

At D speed there will be extra drag but Sleipner have a hunch that the lift from the big curved fin will "pay" for the extra drag at P speed by making the boat semi-hydrofoil. We might want more stern lift too and if that's the case I have the option to install bigger flaps (because I already have upgraded flap hydraulics, installed during build) or just add some Interceptors. Or even a pair of fixed interceptor blades.

Interesting concept. I fully agree that the only way to get meaningful results is by experimenting, so yes, I'll definitely stay tuned 'cause I'm curious to hear the differences (if any) you will see in engine load/consumption, at any given speed.

But in the meantime, just to speculate a bit (yes, there are a few odd rainy days also here, during the NZ summer...):
1) efficiency of planing hulls basically depends on two factors: hydrodynamic shape and wetted surface.
2) hydrofoils normally work not because they are very efficient from an hydrodynamic viewpoint, but because by lifting the hull significantly (or even completely) above the water, they drastically reduce the wetted surface.

Now, fin stabs on a P hull can surely increase the hull lift. It's easy to see that, and btw, not just with curved fins.
Actually, IF (and it's a big if) that effect would be relevant, it could be easily increased via software, by setting the centered fins position slightly inward, instead of neutral to the water flow (that is probably slightly outward, at P speed).
Anyway, any wetted surface reduction, per se, means better efficiency. But only as long as it isn't counterbalanced by worsening the hydrodynamic shape (additional drag induced by the fins and their position).
Now, if I understood correctly what you meant, you are expecting ad additional lift with curved fins, AOTBE.
To the point that such additional lift - which at P speed obviously works by lifting the bow, rather than the whole hull in a "neutral" fashion - could increase the AoA enough to require some additional stern lift.

Which brings us back to the balance between wetted surface and drag:
If these assumptions would be true, IMHO the wetted surface reduction would be nowhere near enough to compensate the additional drag of the hydrofoils (fins) PLUS the interceptors or whatever at the stern.
In fact, we would still have a "traditional" P hull (as opposed to a full hydrofoil boat), planing exactly as before, just sitting a little bit higher (how much, realistically? Probably better measured in millimiters than centimeters... ) on the water. But on top of that, with some non trivial additional drag.

Anyhow, as I said, I'm just speculating.
It'll be interested to hear more about all that when you will have some numbers! :encouragement:

 

[MapisM]

Re Ancam,
MapisM we have to disagree on this one,
Our Ancam is in the most perfect position, as if you are standing on the bow, and looking forward right down to the anker and the chain.
This is absolutely a practical solution for a real problem, more on that later in one of my own threads,
MapisM There is only one way to convince yourself how practical this is, and that is to come again onboard of BA and experience this huge practical benefit yourself

Yeah, I know, I know... I was just pulling jfm leg a bit, after he posted "AnCam TM" on JTB thread...
But if you insist, of course I'd be quite happy to experience the thing in flesh on BA!

 

[jfm]

Haha, good point. Pretty much the same as the (albeit increasingly popular, I must admit!) AnCam....?
Running for cover now...

MapisM the AnCam is awesome! I might have to make it my life's ambition to persuade you and read a post on here from you saying "Yup, JFM has a point, that AnCam is a darned good idea!". Think I'll have to bring it south and show you

 

[jfm]

@BartW -
Thanks. Yup, the look of the thing is quite sensitive to camera angle. In profile it looks ok to me, but from stern 1/4 looks top heavy. I don't mind, and when you're standing on the flybr deck it looks/feels very impressive.

I'll measure the height for you and report back. The guttering and detailing is complex - it would be quite a job to diy this, unless you accepted simplifying all that and having the canvas roof overlap the GRP so there is no need for guttering. Maybe you should start a new thread on design of a self-build HT

Yup re teak. I'm quite relaxed about it though because I can sand it when I want, and if I sand too much away I can email Wattsons, who have the CAD files, and just get new panels made. OK, it takes some work to fit them, but any good shipyard can do that. So my view of decks is that they are not Faberge eggs - I'm referring only to glued on deck panels on a plastic boat of course, not "real" teak decks

My capping rail varnish is International Schooner Gold. This is their highest UV resistant product and they claim better in UV than Epifanes http://www.yachtpaint.com/LiteratureCentre/schooner-gold-pro-sell-sheet-NA.pdf. I have no idea which is better, but I'm v happy with the way the Schooner gold is going on. It is probably splitting hairs to debate Epifanes vs Schooner Gold. I'm having several coats of gloss applied but then I'm thinking of a top coat in matt/silk - not sure yet

@MM. Yes, I see your line of thinking and cannot fault your speculation. Except to say, the curve on these fins is possibly much bigger than you imagine, so that the tips are only about (I haven't measured) 25 deg below the horizontal. I'll post photos next week but the horizontal plane area component of each fin is something like 0.5m sq. 1 metre square total of horizontal plane effective shape @23kts is going to give more than mere millimetres of lift, I guess. But I'm speculating too, and am interested just to try it. As mentioned, it is easy to switch to 0.7m sq fins. I'll report back, and indeed hope for a sea-trial this saturday

 

[Jonmendez]

Not quite to the same scale but we sanded Motala's original teak decks last year - 28 years old and still over 8mm left came up like new, my reason was where the caulking stood proud we were getting little puddles of standing water. Now looks like new and the water drains much better. As part of the process we also replaced a few of the teak dowels that had worked lose over time.

 

[MapisM]

MapisM the AnCam is awesome! I might have to make it my life's ambition to persuade you and read a post on here from you saying "Yup, JFM has a point, that AnCam is a darned good idea!". Think I'll have to bring it south and show you

Actually, jokes aside, as I recall I already conceded at some stage that it can make sense, depending on the specific ground tackle and also on personal habits/preferences.
The fact that on my boat it's necessary to have someone at the bow when dropping/recovering the hook makes the AnCam obviously trivial for me, but this doesn't mean that the same applies to all boat.

Regardless, of course I would be more than happy to see the real thing (and also all other upgrades!), if you would head a bit further S, for a change.
Btw, there will be several forumites around my usual backyard this summer, so you could catch up also with other folks.
Looking forward to read that M2 will join the fleet on Hurricane thread, if/when you'll make up your mind!
(www.ybw.com/forums/showthread.php?421307)

 

[MYAG]

The hardtop looks very good and certainly a massive improvement over the bimini on this size boat imho. All hardtops on boats this size and much bigger have a habit of looking a bit out of scale/top hatted relative to the overall boat when viewed at certain angles in photos, now't to worry about there, up close and personal it will look amazing from any angle. In Antibes over the weekend, will pop over to take a closer look if she's there. Very nice proper job in an impressive time frame. (JTB, how much longer is your platform going to take mate? )

 

[jfm]

The hardtop looks very good and certainly a massive improvement over the bimini on this size boat imho. All hardtops on boats this size and much bigger have a habit of looking a bit out of scale/top hatted relative to the overall boat when viewed at certain angles in photos, now't to worry about there, up close and personal it will look amazing from any angle. In Antibes over the weekend, will pop over to take a closer look if she's there. Very nice proper job in an impressive time frame. (JTB, how much longer is your platform going to take mate? )

Hi M. I'm launching Saturday am and maybe doing a few sea trials before the sleipner team heads for airport/flight back to Norway so I'll be back on berth Saturday pm I guess. Drop by if you're around in the afternoon. EME might be around (need to ask him); Jenny isn't - she's on a michelinny residential yacht chef course while boat is drydocked

If you fancy a trip out to sea come to shipyard ("Bleumer" yard, the only one there with a travelhoist) at Baie Des anges marina (aka Villeneuve Loubet) earlier. 10 am ish I think. Its the marina with the big (huuuge) swoopy apartment blocks, 4 miles along the coast NE-wards from Antibes port, literally the next port along the coast NE-wards from Antibes port.

You're looking at berths I hope!

 

[MYAG]

Hi M. I'm launching Saturday am and maybe doing a few sea trials before the sleipner team heads for airport/flight back to Norway so I'll be back on berth Saturday pm I guess. Drop by if you're around in the afternoon. EME might be around (need to ask him); Jenny isn't - she's on a michelinny residential yacht chef course while boat is drydocked

If you fancy a trip out to sea come to shipyard ("Bleumer" yard, the only one there with a travelhoist) at Baie Des anges marina (aka Villeneuve Loubet) earlier. 10 am ish I think. Its the marina with the big (huuuge) swoopy apartment blocks, 4 miles along the coast NE-wards from Antibes port, literally the next port along the coast NE-wards from Antibes port.

You're looking at berths I hope!

All possibles J, will be in touch. Cheers.