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  #46  
Old 03-23-2007, 05:47 AM
bilgeboy bilgeboy is offline
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I love this thread.

I have managed to stay out of it for so long now, don’t know why I have failed to refrain myself now.

A few things. Newcastle in a can is worth researching. I might try some research tonight.

I agree with sealing up the cans real tight. I would put a dab of epoxy on a toothpick, and allow this to set up on the metal tab that gets pushed down into the can.

When cured, this will allow you to pull the tab up to its former position at the top of the can.

It’s then just a simple matter of welding the tab back into position. Probably a small TIG machine would be ideal for this tedious, but so important, job.

A small grinder to remove the toothpick, and Voila!

It sure would give you a lot of peace of mind knowing each can was sealed so tightly. You don’t want to be sweating that out in the rough stuff!

Mike
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  #47  
Old 03-23-2007, 10:22 AM
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alan white alan white is offline
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You sound like you've been researching already!

A.
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  #48  
Old 03-23-2007, 03:04 PM
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djwkd djwkd is offline
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hmm..i think all this may be over my budget so ill just include milk bottles and soda bottles.
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  #49  
Old 03-23-2007, 10:02 PM
bilgeboy bilgeboy is offline
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Sorry, Alan. I need all my faculties fully intact for such brilliant ideas!

Seriously, what I love about this thread is that is sounds crazy...at first. You give it some time and thought, and you kind of want to try building something. Thats why I ignored it for so long.

When I was much younger, my cousins and I would have to build a raft to play on the lake every couple of years. They were short lived. We would nail a sheet of 4x8' ply to a 2x4 frame, and stuff it with whatever foam was lying around. We didn't sweat closed cell or open back in the day. Another 4x8 sheet on the other side, and we had a raft. It was great. Playing "King of the Raft" was an obvious game that provided hours of summertime fun. Though I be a lowly bilgeboy now, I had my seconds of fame as "King of the Raft". A few scars from protruding nail heads are still visible.

These rafts would soak instantly, be incredibly heavy, and provide tons of fun.

I also remember the days when I was a little less hefty, in the first years of college. I used to be able to stand on one foot on top of a beer can. A second "researcher" would just flick the side of the can with his finger, and the can would instantly crumble under my weight. No engineering majors in that crowd, but we all found it interesting and entertaining.

Anyway, I think a flotilla of empty beer cans epoxied between two sheets of luan ply, with some wood sides, and wrapped in a layer or two of 6 oz would make an incredibly light, but very strong raft.

With some more "research", I just might try it.

Mike
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  #50  
Old 03-24-2007, 01:25 PM
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djwkd djwkd is offline
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Ok,thankyou for that suggestion.I have now ordered some Epoxy.
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  #51  
Old 03-24-2007, 03:07 PM
SamSam SamSam is offline
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Quote:
Originally Posted by alan white View Post
Aluminum will dissolve in salt water, I think.
A.
Real fast, I think.
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  #52  
Old 03-24-2007, 03:48 PM
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djwkd djwkd is offline
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Originally Posted by Figgy View Post
Why not just seal the frames up and have that be your floatation?

because the seal may not be too strong,also,this defeats the object of it being a raft,and if it were to beach or ground it would sink.That is the main reason why i wish to build a raft.
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  #53  
Old 03-24-2007, 11:35 PM
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alan white alan white is offline
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I read Huckleberry Finn six months ago, hadn't read it in 30 years. There is something about a raft easing down a river at night, maybe a tent and a cookfire aboard. My daughter told me a former boyfriend had made a raft to float down the Penobscot river, and some official so and so accosted him midstream and told him the raft was unsafe and he had to abandon it.
Actually, the official had no such authority, and there was a standoff, raft and boy calling the bluff.
Boys still take to rivers in rafts, thank God. Not enough of them, but some.
Here's an idea: Plastic culverts are cheap and light and if one were to pinch together the ends and melt-weld-rivet-tar them into prows...
Okay, fill them with a lot of capped bottles and rig a pump. Remembering they ferry rather than steer, and do not actually go faster than steerageway would require---- the ribbed surfaces of the culverts wouldn't matter much hydrodynamically speaking.
Forty years ago I'd have been up all night thinking about it.

A.
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  #54  
Old 05-17-2007, 01:00 AM
geedee69 geedee69 is offline
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Cans for raft

I think a 2 litre plastic bottle will provide about 1 kg of flotation...many sailing dinghies use these as added floatation... regards, Geedee

http://groups.msn.com/FerroCementYachts
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  #55  
Old 05-17-2007, 01:57 AM
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djwkd djwkd is offline
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So one litre capacity (bottle)=1KG if fkloatation???COOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOL!my raft will not,not sink... LOL i'm goin crazy!2 pieces of extra good news in a row!
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  #56  
Old 05-17-2007, 05:26 PM
geedee69 geedee69 is offline
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Floatation

hi there,

Sorry I made a typo in my reply ... it should have read " a 2litre bottle will provide 1 kilogram of floatation lift"....... I have edited my last reply ...

When I was not so old I used to sail a plywood "Sunburst" sailing dinghy I used plastic bottles for added flotation, they were more simple and easy to fit into the compartments than polystyrene foam and worked well.

regards,

Geedee

Invercargill
New Zealand
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  #57  
Old 05-18-2007, 10:13 AM
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djwkd djwkd is offline
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Cheers for that edit-it could have cost me the raft if oyu didnt add that!
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  #58  
Old 05-18-2007, 10:27 AM
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Bergalia Bergalia is offline
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Drink cans, beer cans etc

Seem to remember that 'wine in a box' had reached Newcastle when I was last there (20 odd years ago). Why not use the inner bladder from the cardboard casing. Not only will it look prettier - but also add a touch of class....
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  #59  
Old 05-18-2007, 10:45 AM
hmattos hmattos is offline
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I would avoid the cans as it will cause all sorts of corrosion isses, since most cans have aluminium sides and steel lids. Further the stell could affect you compass.
I would consider polypropylene bottles. The cheap solution is empty 4 pint milk bottles, or bigger catering containers if you can find them.
Then wedge them firmly into your locker space, drill a drain hole for safety and screw down the lid. Each season you can inspect all is well.

We are no longer allowed to have sealed chambers without some sort of drain as too many of them ended up sealed with water in them!

God Luck
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  #60  
Old 05-21-2007, 02:32 AM
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djwkd djwkd is offline
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Ah,yes.soory i forgot to tell you all-i've ditched the cans and taken them out of the hulls in the raft,thankyou for telliing me about the corrosion.


Dominic.
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