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**GordMay** · 28-02-2011, 07:53

Quote:

Originally Posted by CaptainAlf

... If you're going to the tropics the only material that lasts is Hypaloon! In those days the yacht line of Zodiac was all Polyester, the worst crap on the planet (huge blisters, opening seems etc.)...

Alf mean to promote Hypalon over Polyvinyl chloride (PVC).
Polyester is actually an excellent fabric, though not for inflatable boat hulls.

goprisko · 28-02-2011, 09:05

I did a quick search and found the following which have complete plans for
oars.

Danny now can be reached via email at:

dtgreene@ibl.bm

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goprisko · 28-02-2011, 09:13

Attached is a webpage filled with photos of how a chameleon is built..../

Sailorgirl! Building Robbie

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zee · 28-02-2011, 09:32

Brent, trying to figure steel vs. aluminum costs. Questionable if shot blasted and primed steel is available and if so it might be prohibitive. Two questions:

Is it absolutely necessary to sand blast?
Can three coat epoxy barrier go over bare metal?

Sailmonkey · 28-02-2011, 09:36

Steel fresh from the mill needs to be blasted prior to coating, Nothing will stick to the mill scale or accompaning oils.

goprisko · 28-02-2011, 10:43

I've been looking for these for some time now... for my own project.

As I mentioned earlier, with bronze poured sockets you can make up your own rigging very cheaply.

Port Townsend Foundry makes them and other custom bronze items, including a single speed manual windlass.

See:

Port Townsend Foundry in Washington

INDY

goprisko · 28-02-2011, 10:51

Quote:

Originally Posted by zee

Brent, trying to figure steel vs. aluminum costs. Questionable if shot blasted and primed steel is available and if so it might be prohibitive. Two questions:

Is it absolutely necessary to sand blast?
Can three coat epoxy barrier go over bare metal?

Mill scale must be removed. In aluminum construction, a 9" makita grinder with 24 grit wheels is used. This works and takes time.

Sand blasting with black beauty is preferred, not shot blasting. You need a ragged profile to get proper adhesion. The plate must be painted within hours depending on the humidity.

Plate coated with a shop primer used to be a common item. Some builders went to corten steel because the oxide tightly adheres to the surface. However, corten did not prove longer lived in the marine environment. The problem with steel hulls is moisture from the accomodation passes through the ceiling and the insulation and lies against the hull. It runs down into the corners made by the frames touching the hull. Because the frames are only intermittently welded, there are many crevices where moisture can lie, and which cannot be coated or sand blasted. It is in these crevices that corrosion does its work. The reason aluminum is superior, is the marine alloys are not affected by such moisture, and corrosion does not occur in these crevices, and because of this there is no need to sandblast the interior with it's attendant expense.

It was recommended that the interior, and exterior of steels hulls be sand blasted to white then spray coated with molten aluminum/zinc. Hulls so treated last a very long time. But this process is very expensive, and once you include it in the cost of your hull, aluminum is cheaper.

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goprisko · 28-02-2011, 11:06

One website I visited today has a page concerning scrounging wheel weight metal for use in balllast keels.

Wheel weight metal is 3% antimony / 97% lead, can be had by scrounging it from tire stores and gas stations. You need to set up a route and go to each store quarterly. But you can get the metal for about 12 cents / lb that way.

If you are thinking of building, you will need thousands of pounds of lead for ballast, and wheel weights are a convenient way to get it.

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goprisko · 28-02-2011, 11:11

Quote:

Originally Posted by zee

Brent, trying to figure steel vs. aluminum costs. Questionable if shot blasted and primed steel is available and if so it might be prohibitive. Two questions:

Is it absolutely necessary to sand blast?
Can three coat epoxy barrier go over bare metal?

For prices on material you need to go to Thomas's Register. Libraries have copies. It is online too. You need to set yourself up in business, this means a taxID for sales tax. You want to go to second sources, you are looking for watermarked plate. You must buy all the material in one go to get the best price. Aluminum prices are least when bought in 5000# lots, the next break is at 2500#, then 1250#, then 500#, then 250#, then 100#. The price goes up substantially as the quantity drops.

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goprisko · 28-02-2011, 11:22

It seems that some readers are considering building rather than buying an old boat.

There are actually very good reasons for building a boat in this size range.

The first thing which must be tackled is the budget. The budget determines the type of boat that is feasible.

The second thing which must be accepted is the skill level of the builder. Higher skilled folks can build more complicated boats.

The third thing which must be accepted is the location of the project. It is best if the project can be built at home.

There are many attractive mult-chine designs in this size range suitable for metal construction, or ply construction and for a builder with modest skills.

Round bilge or radius chine construction requires more skill and support from a machine shop.

Carvel plank construction is a fast way to get a hull, if you have the skill and a supply of material.

Best reason to build is to get more tankage, a custom accomodation, or shoal draft. Since most boats this size have large heads and vee berth cabins, one can easily improve them by removing the head, placing the wc beneath a box or shelf in the forepeak, and configuring the forepeak for storage, generally making it 2 ft shorter. This frees up space midships for a U shaped galley, standup chart table, and a larger, 8ft long saloon with setees, sideboards, bookshelves, heater, etc.

Since all the fasteners will be new, there will be no need to pull and replace them.

Costs can be reduced by purchase of an old boat and recycling the mast, boom, cleats, winches, sinks, ballast, and other items. This will leave the hulk to be disposed of.

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**GordMay** · 28-02-2011, 12:07

Quote:

Originally Posted by zee

... Is it absolutely necessary to sand blast?
Can three coat epoxy barrier go over bare metal?

Sure, as long as the steel is as bare as if "blasted" clean.

CaptainAlf · 01-03-2011, 01:41

Quote:

Originally Posted by boatman61

There's a rubberised paint you can get for that... should give you a few more years...

Thanks, but found that stuff on the net already, but not a single genuine review about it. Then the price and the shipping to Thailand amounts easily to 250$ for a 10f RIB. I rather stick to my thin layer of epoxy which I will try to cover now, so I don't have to do it every 6 month again when the epoxy gets brittle because of the UV.

CaptainAlf · 01-03-2011, 01:47

Quote:

Originally Posted by GordMay

Alf mean to promote Hypalon over Polyvinyl chloride (PVC).
Polyester is actually an excellent fabric, though not for inflatable boat hulls.

Yep, of course PVC, sorry about the mistake - somebody else mentioned the West Marine tenders, that's exactly the stuff i was talking about as an absolute no no.

sctpc · 01-03-2011, 01:52

Quote:

Originally Posted by CaptainAlf

A few things to know and consider when buying an inflatable:
If you're going to the tropics the only material that lasts is Hypaloon! In those days the yacht line of Zodiac was all Polyester, the worst crap on the planet (huge blisters, opening seems etc.).
If you get a small foldable one, don't get one with a flat bottom but with an inflatable keel. Huge difference when rowing or under engine.
The best value you will get in the carrebean. Carib and AB are formidable RIBs. As soon you're leaving the carrebean going west, there is a huge gap where is nothing to get for reasonable prices until NZ and OZ. And there you get Aquapro with a much lower bow and smaller tube diameter, meaning you get soaked when driving against the wind while I stay dry in my old Carib.
Last but not least a chance to learn from my mistakes: Cover it up! I would have gotten at least 3 to 4 years more out of my Carib if I would have done that - the biggest problem are tiny pin holes in the worn surface.

Ok, that's it for today, perhaps next time about one of the biggest cost factors: The rigging?!

Cheers

Alf

My Zodiac is PVC and to renew it and fix pin holes I use clear pvc priming fluid from my plumber shop its $6 for 500ml 1 lt brings it up like new.