3 blokes, 3 days, £300 - First draft of Centaur Well design

tyce said:
Still don't get it, the Centaur by his own admission is a better, bigger and safer boat which will cost less than the Hunter, so keep it?
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Define "better"? As Dylan frequently points out, even a forty-foot Oyster is not a "better" boat for his purposes, because its draft restricts it to the mouth of the river rather than the sinuous upper reaches. This is a man who uses a three-foot stick as a depth sounder as he drifts along revolving slowly in the tide. The Centaur can dry out, but it can't get into such shallow places as a centreboarder. It also can't get under bridges, whereas the Hunter's wooden sea-rig can be dropped with a little effort and the Topper inland-rig with none. I don't know whether you can tow a Centaur, but even if you can it will be a lot more hassle than the Hunter.

The Centaur is a better boat for the more exposed bits, which is why Dylan is getting it, but for his purposes it's not universally better.

Pete
 
This outboard well thing is not so unusual. A lot of small multihulls have them. I had trimarans from 26ft up to 36ft all powered with outboards. By the way I sailed in all those 'nasty' places mentioned so no remarks about multi's cannot take the rough stuff!
In my experience wells work very well!!!!! The problem will be enough power for a tubby boat and fuel stowage.
 
If you are going down the OB route why not go for a round or semi-circular section tunnel for the OB. The stresses (hull to housing) would be better distributed and like the PVCu tube you originally thought of using it would be more aesthetically pleasing.
 
Dave100456 said:
If you are going down the OB route why not go for a round or semi-circular section tunnel for the OB. The stresses (hull to housing) would be better distributed and like the PVCu tube you originally thought of using it would be more aesthetically pleasing.
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A quick google suggests that GRP pipe of suitable diameters is available for the drainage world.
 
prv said:
Define "better"? As Dylan frequently points out, even a forty-foot Oyster is not a "better" boat for his purposes, because its draft restricts it to the mouth of the river rather than the sinuous upper reaches. This is a man who uses a three-foot stick as a depth sounder as he drifts along revolving slowly in the tide. The Centaur can dry out, but it can't get into such shallow places as a centreboarder. It also can't get under bridges, whereas the Hunter's wooden sea-rig can be dropped with a little effort and the Topper inland-rig with none. I don't know whether you can tow a Centaur, but even if you can it will be a lot more hassle than the Hunter.

The Centaur is a better boat for the more exposed bits, which is why Dylan is getting it, but for his purposes it's not universally better.

Pete
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bless you Pete

that is exactly it

as we all know there is no best boat

there may not even be a better boat

I started with the slug - because it was the right price in the right place and I was sailing in shallow waters and leaving it in grotty places where thievery from boats is rampant

the life expectancy of an outboard in Wells was really short for a while - they have licked the problems now.... I left it on the Medway for two months....I left it at Brightlingsea for a winter

the only thing I lost was a tank full of diesel - may the scrotes rot in hell


I wanted a boat that sat up on the mud and would be the last boat anyone would ever bother breaking into

when I got to wells I realised that the slug was too high and too deep to explore the salt marshes to I built the duck punt

then the beast started giving me serious gyp - I sold my starlings films a few times and inherited some money so I blew it all - every last penny - on Katie L (the boat I shall keep until I rswallow the anchor)

this summer I have some pretty tough waters to face and four on-board

we shall see if the Centaur works

they are bloomin tough old boats

but most of all they are cheap old boats with astonishing accommodation for 26 feet

but after this summer when I am back by myself it will be too big and I will not, as petse says, be able to take it up the rivers

I have had a few emails accusing me of cheating when I abandonned the slug

I am sure that a few people will feel double cheated if I swap boats for a while and sail for a bit with my family

I might even lose my column on Small Craft Advisor for being a traitor to the cause because I will have full standing headroom

I learned a lot coming up the East Coast

- first

is that there are a lot of lovely little harbours that I really do not want to miss

second

Scottish Harbour walls can mangle your topsides before you can say knife.

three

after 50 consecutive days and nights on board I realised that full crouching headroom is fine when the sun is shining - but bloomin tough when you are confined to harbour for a week

Dylan

PS - still looking for a solent based Centaur with a nacked engine and a spade rudder

dylan.winter@virgin.net
 
Dave100456 said:
If you are going down the OB route why not go for a round or semi-circular section tunnel for the OB. The stresses (hull to housing) would be better distributed and like the PVCu tube you originally thought of using it would be more aesthetically pleasing.
Click to expand...

the man from Wessex resins - he say no plastic pipe of any sort

and he is in the driving seat for keeping the water out

when I go into full production of the KTL Centaur conversion kit then I could get a GRP molding made up - drill a 315mm nole in the cockpit floor, shove the pipe down it - everywhere it touches the hull drill more small holes - join them up with a jig saw cut - stick a bit of 2 x 4 across the cockpit

bingo



D
 
dylanwinter said:
when I go into full production of the KTL Centaur conversion kit then I could get a GRP molding made up - drill a 315mm nole in the cockpit floor, shove the pipe down it - everywhere it touches the hull drill more small holes - join them up with a jig saw cut - stick a bit of 2 x 4 across the cockpit
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You could do that now if you wanted to. I'm in the process of laying up two substantial cockpit pods to hold a large plotter and a collection of other bits and bobs - no reason the same techniques couldn't be used to make any other mouldable shape.

Pete
 
prv said:
You could do that now if you wanted to. I'm in the process of laying up two substantial cockpit pods to hold a large plotter and a collection of other bits and bobs - no reason the same techniques couldn't be used to make any other mouldable shape.

Pete
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Looks interesting... Will you be taking lots of pictures/video? I'd like to try that some time?
 
Barking up the wrong tree?

In SE Asia at the moment. V impressed with sampan and pirogue engining.

Sampans seem to have standardised on a 20hp single cylinder diesel mounted in the open, vectored to steer, lift able shaft for dead shallow use. Look up Amec engines from China. Told they cost $700 less drive shaft and prop.

Pirogues use a 10 horse watercooled version.

Either would mount on the lazerette and save all this business of cutting holes in the bottom of an offence less little Centaur.

It would be the first longtailed Centaur and sight to behold.
 
chrisbitz said:
Looks interesting... Will you be taking lots of pictures/video? I'd like to try that some time?
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Only taken one picture so far, and that's not very good.

I started off with a wooden core that was very, very approximately the right shape (no cutting involved, I just grabbed assorted chunks of wood and nailed them onto the blob, bit like dry-stone walling). Then wrapped it in plenty of clay to form the actual shape - the wooden core was just to reduce the amount of clay needed and hence the weight to carry the things around. Spent most of an afternoon tooling the clay into shape and making it very smooth - and ensuring it was properly tapered so the moulds will release. No need to let the clay dry, just paint it with two coats of sealer designed for dusty concrete floors, which gives a plastic skin. Then flowcoat over that to give a surface I can sand (couldn't get the clay quite smooth enough). That's where I am now - since the shed is not that warm I'm giving it plenty of time to set hard before I try to sand it.

Once I've sanded and polished the gel-coat on the plug, I'll apply wax and/or PVA release agent - haven't decided which. Note this PVA is polyvinyl alcohol, not polyvinyl acetate glue. Then paint gelcoat over it, leave to go tacky, then start laminating glass and resin over the top. Once that's gone off, I will (hopefully!) be able to remove it and that will be the actual mould. Make sure that's all smooth and shiny (can sand and polish it if required, but being concave it will be more difficult than the plug so hopefully not needed) and then give it plenty of coats of wax. Then paint in the final gelcoat and (once tacky) apply the laminate, and job done.

Pete
 
prv said:
Only taken one picture so far, and that's not very good.

I started off with a wooden core that was very, very approximately the right shape (no cutting involved, I just grabbed assorted chunks of wood and nailed them onto the blob, bit like dry-stone walling). Then wrapped it in plenty of clay to form the actual shape - the wooden core was just to reduce the amount of clay needed and hence the weight to carry the things around. Spent most of an afternoon tooling the clay into shape and making it very smooth - and ensuring it was properly tapered so the moulds will release. No need to let the clay dry, just paint it with two coats of sealer designed for dusty concrete floors, which gives a plastic skin. Then flowcoat over that to give a surface I can sand (couldn't get the clay quite smooth enough). That's where I am now - since the shed is not that warm I'm giving it plenty of time to set hard before I try to sand it.

Once I've sanded and polished the gel-coat on the plug, I'll apply wax and/or PVA release agent - haven't decided which. Note this PVA is polyvinyl alcohol, not polyvinyl acetate glue. Then paint gelcoat over it, leave to go tacky, then start laminating glass and resin over the top. Once that's gone off, I will (hopefully!) be able to remove it and that will be the actual mould. Make sure that's all smooth and shiny (can sand and polish it if required, but being concave it will be more difficult than the plug so hopefully not needed) and then give it plenty of coats of wax. Then paint in the final gelcoat and (once tacky) apply the laminate, and job done.

Pete
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Pete has just become head of production at the KTL Enterprises Centaur butchery department

D
 
Hmmm! Not wishing to p**s on anyone's chips here but you know those stories you here in Yachting Monthly etc about some Captain Catastrophe setting sail in a home made/modified boat and getting into all sorts of difficulties...............well draw your own conclusions! I think it may be time for people to stop 'enabling' the madness and get a cab back to real street. Lets face it, if pushed you could re engine a Centaur more reliably with an old Ford 1.6 diesel and the marinising bits for about the same price. You would also end up with a boat that had at least some intrinsic value on paper at the end of this.
 
dylanwinter said:
the man from Wessex resins - he say no plastic pipe of any sort

and he is in the driving seat for keeping the water out

when I go into full production of the KTL Centaur conversion kit then I could get a GRP molding made up - drill a 315mm nole in the cockpit floor, shove the pipe down it - everywhere it touches the hull drill more small holes - join them up with a jig saw cut - stick a bit of 2 x 4 across the cockpit

bingo

D
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Re post #26
Sorry maybe not made myself clear I meant fabricate a 'D' or round section O/B housing from ply not PVCu. A twin wall structure will be very strong and could be glassed over to protect from water ingress. I guess the hull will be of substantial strength where you cut the hole but when a square/rectangular O/B housing is glassed in it will induce stress points at the corners. A curved shape would distribute loads more evenly as well as looking nicer.
 
I rather suspect any scrap value from the metal bits and gear would be a good deal less than the cost of disposing of the hull,

I don't have a problem with scrapping a Centaur per se, it's not some classic or historic boat, but I think you're being optimistic if you think it's a zero cost option

I do like the idea of moulding a GRP tunnel though it's technically more challenging to produce something strong enough with reinforcement in the right places
 
Storyline said:
If the video hits keep rising he might be able to afford to run two boats - one for the east and one for the west.

(not written entirely in jest)
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Sadly there is no formula for converting YouTube views into money. Making online video is a great way to promote your product / service / project at low cost and with a potentially huge audience, but any notion that the videos themselves can make you rich enough to run two boats is unfortunately nonsense.
 
It looks like the centaur has quite a nice deep cockpit. I know someone with a pageant and they close the cockpit drains before sailing to stop water coming up into the cockpit through them. Does the centaur do the same? It would be rather more difficult to stop water coming through an outboard well and that lip to attach the outboard clamp onto doesn't look very high... You can't move it up too much as otherwise it looks like it would foul the tiller?
 
It's difficult to understand why you are happy to create something of a quality 'that need only last 18 months'.To do so is to accept from the outset that you are doing something that no-one else would want to do or buy ? You are missing the point about marine ply.Firstly,unless you want a particular face veneer,it is not expensive for what it is,and is far more stable than typical WBP.Secondly it is formed from durable species,normally a tropical hardwood.That means that you can bury it in the ground and in a couple of years time it will be unmarked and mould free.Typical WBP will gather mould if you leave it in the rain and it will buckle at the least opportunity.If there is any break in the grp skin the WBP will take up moisture that will be held captive and foster rot that is inaccessible.It is very easy to bond sheets of marine ply together where it is necessary and in any case it's dense composition and freedom from defects allows greater permissible stresses.
It doesn't make sense to skimp.Make a job of it.
 
Seriously beginning to thing this whole thing is just a wind up.

"I can extend the rudder shaft if needed to clear the OB". Dylan, do you know how much of an undertaking that is to do properly and ensure that it's square, properly supported, and will deal with the not insignificant loads on a tiller of a boat of this type?

"3 blokes, 3 days, and if I want to swap the wood over it's only a day..." Haha!!!!! Have you ever worked properly with epoxy resins? Do you realise you could throw 20 blokes at it and it won't happen any faster? Most of the build will be you doing precisely nothing as you wait for the last bit to dry before you come back to it to do the next bit. I would want colossal fillets and many layers of cloth holding that lot together...that takes ages to do. It took me weeks just to split a rudder open and reglass a repaired shaft back in. Weeks. Even removing the stern tube, glassing the hole up, fairing it, putting the relevant VC tar or similar and antifoul on is not a small task, and that's a teeny hole.

What on earth is the point of using softwood when you will be throwing hundreds, yes hundreds of quids worth of epoxy materials at this project? Why not do it properly initially? If you're not paying for it because of some sponsorship tie in, do you really think that Wessex resins will be that happy about being associated with a boat with potential structural defects that might sink with you in it, or years later once it's been abandoned somewhere or sunk on its mooring? Have you consulted a naval architect as suggested? Done the sums to consider the lost bouyancy at the stern? Thought about the increased loads on the rudder tube now it's not as supported as it was? Considered the waterline at an extreme angle of heel or a big following sea? Spoken to whoever is going to insure the boat for you? "Have you had a hull survey and the rigging changed in the last 10 years? Nope, but I've cut a hole in the bottom and made a softwood engine bracket to a fag packet design..."

I absolutely get the attraction of an outboard WRT cost and arguably manoeuvrebility. Can you cut a hole in the bottom of a centaur and make it outboard powered? Of course you can, but is it even slightly sensible?

Dylan, many people have contributed here and generally get a brush offish response to any questions posed. I even spent ages digging around in my loft to find you the article on outboard powered Sabres to photograph and send to you and did'nt get even a "thanks" but I guess you are busy starting all these threads...

Just do me one favour and please please please tell me why you have to chop a hole in the bottom of it and do this well idea rather than using similar ingenuity to hang it over the back. Standard pantograph bracket, perhaps on a mount that would slide up and down to give more depth? Two bits of stainless u shaped channel and a hardwood board?

Don't get me wrong, I love your films and your outlook on doing things a bit differently, but to be frank I don't think you have any idea of what you are taking on here and the drawings and ideas hardly fill me with confidence. This is not a duck punt. It would be a shame to see a centaur ruined, a project abandoned, or people and boats lost. It's the "3 days, a few quid, a few blokes, bit of PVCu, a bucket of resin and some softwood and it'll all be fine" approach that I find really worrying.

Potential scenario. You are doing your creek crawling thing, the Tohatsu is chugging along nicely at 5.5 knots, there's 2 knots of tide under you, so when the large concrete obstruction slides perfectly between the keels of your bilge keeled centaur, the outboard leg and a couple of tons of westerly hits it at a speed of 7.5 knots. Obviously the leg can't ride up as it would normally (or for that matter transom mounted) as it's in it's rather narrow well. It slams into the back of the well, right onto the join,as the boat starts to pivot round broadside onto the tide, stuck on the engine leg...which is by now applying a huge twisting force onto the well...just a thought. Better and safer than an inboard? Right-o...
 
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