Is "Poly" the new GRP

[Jim@sea]

Having read about the "Smartwave 490" made out of "Poly" in Boat Magazine I was more impressed by the weight quoted of 400 kilos rather than the design (which is acceptable but is the 4.9 including the engine because it looks like a 13ft boat)
Anyway for my next boat as I want a 20/21ft Cuddy Boat with an outboard, but if "Smartwave" can make a 4.9 m weighing only 400 kilos they could perhaps make a 7m ft boat weighing 1000-1200 kilos which with outboard would tow at 2000 kilos, which is a reasonably light weight to tow and launch single handed.
Also "aparrently" Poly boats are virtually indestructible, and you can fire a shotgun at them. Perhaps unaffected by Osmosis etc.
Is this the future of small boatbuilding.

 

[vas]

its not any poly its Polyethylene.
Nice material used on all sorts of things from kids toys to furniture to whatever.
The typical construction method which is rotomoulding is limiting in terms of shapes and systems that can be "cast" in one go, but if the designer is smart, all sorts of interesting things can be built. I've got some experience with them from using a sea pushbike and helping a colleague design objects made of that (finally business fall through, nothing was moulded just the hours spend designing and discussing the technology and it's quirks and limitations...)

I'd account flex and overall strength as issues when sizes grow, but to an extend depends on design and implementation. IMHO employing this material should lead to crafts that should offer identical functionality but slightly to quite different shape/forms/looks addressing structural capabilities of the new material.

V.

 

[Wiggo]

Our old tender - a Rhino Rider - was rotomoulded polyethylene and 'indestructible'. In reality, it was very heavy for it's size, and when left sitting on tender chocks it eventually hogged badly.

 

[vas]

Our old tender - a Rhino Rider - was rotomoulded polyethylene and 'indestructible'. In reality, it was very heavy for it's size, and when left sitting on tender chocks it eventually hogged badly.

yep, however, you could let it lay upside down on a smooth sandy beach with 35+C sunshine on it for a couple of days and it would reform to original shape.

Also don't think you can stress them with high power engines or anything and noway it's going to replace grp for anything larger than 5m (and if that...)
Wiggo, probably your tender wasn't filled with anything though (as my seabike) then it would be even heavier but would flex less...

 

[Fantasie 19]

Back in the day all my windsurfers used to be made of that stuff - washing up bowl plastic we used to call it - but if it's the same stuff they weren't indestructible... we learnt a lot of hot welding type techniques with soldering irons to repair splits/cracks etc. I don't remember Polyethylene being light either....?? Is it the same stuff??

 

[Wiggo]

yep, however, you could let it lay upside down on a smooth sandy beach with 35+C sunshine on it for a couple of days and it would reform to original shape.

Difficult to do with a mini RIB with a console and a 25hp outboard on it. And don't even get me started on this strange "sunny day" idea...

 

[vas]

Difficult to do with a mini RIB with a console and a 25hp outboard on it. And don't even get me started on this strange "sunny day" idea...

I agree, I was just making a point that rotomoulded stuff do have a "memory" and they can and will come back to original shape if heated (a bit)

BTW, what happened to the british humour, I'm a bit worried that you lot are turning more continental (or is it simply that the non-rain season wasn't long enough this year?)

OK, I'm leaving...

 

[dabsolute470]

" poly " just means made of many, we are resin wall and flooring contractors and use lots of poly... stuffs... its stuffs that mix with others.

 

[Wiggo]

BTW, what happened to the british humour, I'm a bit worried that you lot are turning more continental (or is it simply that the non-rain season wasn't long enough this year?)

OK, I'm leaving...

We don't have a 'non-rain' season here, old chap. Just 'rainy season' and 'slightly less rainy season'...

 

[Lakesailor]

Sun affects that poly whatsit stuff not just softening it but the colour goes and it seems to harden.
Lucky we live in the UK then...........

 

[Morpheous]

Isn't that what they make Toppers out of? Not light, very durable (I've seen a trawler run one down in Plymouth and it was fine) but if you do manage to damage it very difficult to repair properly.

 

[Jim@sea]

Perhaps with "Poly" a boat manufacturer could make the "Hull" out of lightweight "Poly" and have the superstructure made out of "GRP" as normal then you would have the "best of both worlds" Lightweight Hull impervious to osmosis and superstructure for a quality finish.

 

[vas]

Perhaps with "Poly" a boat manufacturer could make the "Hull" out of lightweight "Poly" and have the superstructure made out of "GRP" as normal then you would have the "best of both worlds" Lightweight Hull impervious to osmosis and superstructure for a quality finish.

I think it would take a team of structural and aeronautical engineers to figure out if and how such a combo can work. The GRP should be rigid enough to reduce the flex in polyethelene (usually ss is used in smaller cat/bikes), bonding of the two will be an interesting task btw.
I'd not hold my breath for larger craft as weight will be an issue as another poster mentioned.

 

[Nautibusiness]

Very American, but very fun.

Watch a few of these:

http://www.triumphboats.com/tough-tests/

Around the turn of the millenium, Triumph were called Logic.
We still have a Logic 15 we use as a work boat around the marina and for what it is, it's very good.

Yes they are very tough, but also annoying when it comes to fixings. Everything needs bolting as self tappers un tap themselves very quickly...