Thread: cement boat??? what tha!!!

The first concrete boats were built in the early nineteenth century, but became popular as an amateur built technique in the 1960s as someone else said. The advantage over other materials was the ability to make compound curves easily, potentially giving a better hull shape than other materials for one - offs. The material is also one of the few that is not damaged by total neglect, and if you aren't paying for labour, it is a cheap method of building. These are the positives.

On the negative side, it is very easy to get the plastering wrong and end up with a hull that allows water to penetrate and rust the reinforcing with disastrous results - you need to make absolutely sure that there are no ends of wire at the surface. Making the reinforcing structure is extremely labour intensive - the chicken wire needs to be tied to the rods every few inches, and the rods need to be welded at every crossing to prevent cracks. Satisfactory repairs are almost impossible - if the hull is damaged you need to cut out the damaged bit, chip out the concrete well back from the crack, and rebuild the damaged area from scratch. And even then it may not be successful.

On balance the negatives seem to have outweighed the positives, and with generally more prosperous society and increasing regulatory costs making the hull cost a smaller proportion of total cost, it becomes less attractive. Also the mass produced fibreglass boats "undercut" the market, particularly as they come on the market older and cheaper.

Originally posted by discowhite
i was just on whitworths ordering a cattledog, at the bottom of the
fill out section it asks what are the types of your boat??

power/sail, length and construction.

well the last one is <span style="font-size:12pt;line-height:100%">CEMENT</span> 8O
must be the new ''floating'' cement

cheers phil

http://www.whitworths.com.au/catalogue_request.asp

It's all about the displacement of water phil.

Warships are made of steel and they float, The Titanic was made of steel too but thats not such a good example

If you can create and maintain a void inside the ship ( prevent the water from getting in) just about anything will float included concrete.

They just don't hang around all that long after the get a hole in them. Where as Fibreglass can be laminated in lays with foam inserts to aid boyance when up turned or damaged.

Class dismissed :roll:

Originally posted by Bushie
A work aquaintance of mine is still building (or helping his father finish) one they started probably 30+ years ago...........

Our neighbour across the paddock up the coast has had one sitting in the paddock for about that long too.

I think you'll probably see more on dry land, uncompleted than you will bobbing across the swells

Hey Bushie,

I have been following that same boats construction since I was growing up in Sutherland. My parents now live in Woronora and when I visited them a couple of months ago I noticed that this boat was nearing completion.
It has to be at least thirty years.
The problem still remains for this guy as to how he will launch it and where.
If you hear anything I would appreciate the contact as I live in Qld now.

Cheers
ET.

Originally posted by Yabbie+--><div class='quotetop'>QUOTE(Yabbie)</div><div class='quotemain'><!--QuoteBegin-discowhite
i was just on whitworths ordering a cattledog, at the bottom of the
fill out section it asks what are the types of your boat??

power/sail, length and construction.

well the last one is <span style="font-size:12pt;line-height:100%">CEMENT</span> 8O
must be the new ''floating'' cement

cheers phil

http://www.whitworths.com.au/catalogue_request.asp

It's all about the displacement of water phil.

Warships are made of steel and they float, The Titanic was made of steel too but thats not such a good example

If you can create and maintain a void inside the ship ( prevent the water from getting in) just about anything will float included concrete.

They just don't hang around all that long after the get a hole in them. Where as Fibreglass can be laminated in lays with foam inserts to aid boyance when up turned or damaged.

Class dismissed :roll:[/b][/quote]


Archimedes' principle

Principle that states that a body immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid.

Anyone remeber him :?:

My fat D3 experiences this when we cross rivers

Chris

That's what I want to see,

a lard boat.

I'll call it Tubby.



Cheers
Simon

As Jason said as long as they can displace enough water anything will float. They made tanks float for the D-Day landing by putting skirts up the side so they could float, the water level outside the skirts was higher than the top of the tank, but the high skirt allowed them to displace enough water so with the bottom sealed they floated and drove straight onto the beach. They didnt land on the beach with the yanks, i.e the battle featured in Saving Private Ryan because the american launched them to far off shore so the sank in the rough waters, in other battles up and down the coast they worked a treat and actually went ashore before the troops and took out the machine gunners. Of topic, but interesting history. Matt

:roll: My sister has had two of these type boats,although one was scuttled in bali somewhere by her ex,the second one is doing well and "floating" in the river at Bundaberg somewhere,burrum heads i think,they are a little heavier than the tupperware (f/glass) boats but do ride a lot better in the rougher seas ,just my two bobs worth 8)