Olds cool down

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fergal butler
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Re: Olds cool down

Post by fergal butler » Mon Nov 16, 2015 8:33 am

I did think about buoyancy but figured if the engine,gearbox and all the non buoyant things came in at around 600-700kg I would need about 700 litres of buoyancy to float her and thats a lot of space in a small boat :shock: I could be wrong with my calculations maybe someone else has worked it all out in more detail.


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jenko
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Re: Olds cool down

Post by jenko » Mon Nov 16, 2015 9:25 am

That's about right Fergal I calculated 0.6 cubic metres of buoyancy foam for the riviera and it takes up a lot of space

gdcarpenter
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Re: Olds cool down

Post by gdcarpenter » Mon Nov 16, 2015 10:38 am

The lift bags seem more likely to work. The winch worries me: first your boat, full of water, could weigh more than 2,000 pounds, and now there are 2 more boats at risk, not to mention all that weight supported by a couple of 4X4's, kinda iffy.

Best of luck. It Makes me glad I added floatation on my ZIP, very few GlenL boats built here in the USA seem to add floatation.

I had a fiberglass boat at our boat access only cottage. Unbeknownst to me my father had lost power on an outing previously and hit a log and made a hole In the hull just above the water line. He had his nephew patch it.

One nigh there was a nor'easter, the only wind direction that hits our boats at the dock. Seems that hole had opened up, and bit by bit she swamped, woke up with boat on the bottom of the lake,

Borrowed 16' 4X4 mine shaft timbers our neighbor had brought out and slowly 'levered' it up until deck was flush with water, about 4' depth. Then a bucket brigade to empty her as best possible. Ran out of daylight that day and had to re bail her the next morning.

This was in October in northern Ontario, so the water was NOT warm! I dove and found where there were now very large holes in the bottom of the hull where she had been 'rocking' on the rocky bottom.

My dad had come out too help and the plan was to cut an opening in the sub floor and slap in a heavily siliconed 'patch' on the inside of the hull. As I was headed to the sauna to warm up I noticed that when dad drilled the first pilot hole to get a starting point for the jigsaw water was gushing up.

It dawned on me that if we opened a large hole in the sub floor the boat would flood to the deck level in a heartbeat. Wound up having the only other person there, my not that young mom, bent over the side of the boat in the cold water holding a plastic place mat over the most aggregious hole in the hull for the time it took my father to cut the hole and slap in the patch.

A day later the patch held long enough to tow her the 5 miles out to the marina, with me in the damaged boat ready to cut the tow line rather than loose the tow boat if she sunk again.

To add insult to injury, or injury to insult?, in the sauna I went to use the wooden sauna bucket to splash what I assumed would be cold water over my head. Seems my mother had dipped the bucket into the hot water tank on the sauna stove to 'help me' stay warm.

Spent a good part of that evening sitting on a stool next to the sink having my mother periodically work the old hand pump we have for water, and bending my head over the sink so she could keep my lightly scalds head cool.

Oh, the "Good Old Days"!
This is my first, last and only boat build.

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slug
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Re: Olds cool down

Post by slug » Mon Nov 16, 2015 11:58 am

Fergal; I'd consider sinking 4 plastic barrels with straps and pumping air in to them with a portable compressor. You'd have to use one way exhaust valves (flaps? ) to let the water out and quick connectors for the air hose. Actually if you could keep the barrels from rolling, the air would automatically force the water out the bottom hole and each barrel would float almost 450 lbs, so wouldn't need to be empty.
Used plastic barrels (usually food grade ) are only about 10 to 15 bucks around here.

Doug

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psychobilly
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Re: Olds cool down

Post by psychobilly » Mon Nov 16, 2015 12:27 pm

I'm in the Subsea oil and gas industry and the barrel trick is what the divers used to use to float subsea trees up with (Subsea Chistmas Trees are oil well valve heads on the sea floor for those that don't know) deep water used to be 150'. We have surpassed that these days in water depths over 10,000'. Anyway, in the shallow water in the GOM, the old timers tell stories about the Hurricanes breaking the trees off just above the master valves. The would sink barrels and the diver would attach them to the tree, pull his nemo off his helmet, fill the barrel, and she would float to surface.

I don't see why you couldn't use plastic barrels and maybe either get some net webbing to use to wrap around the barrels so you can attach ropes... Back the day they used steel barrels and just welded pad eyes on them. Heck you could float 6 or 8 barrels out there, pull the caps and sink them, attach them to the motor like you were already thinking.

Today's Subsea industry we are still ringing 100 ton (tonne) Trees with the Delmar buoy system. It works bud.

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Bill Edmundson
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Re: Olds cool down

Post by Bill Edmundson » Mon Nov 16, 2015 1:24 pm

I try to install flotation to match the sinking parts. I put it between frames on the topsides under the ceilings and under the deck. I use polyurethane sheets cut to fit. I done care for the form in place stuff. I've used it. But, Don't like it.

Bill
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Re: Olds cool down

Post by fergal butler » Mon Nov 16, 2015 5:05 pm

Bill Edmundson wrote:I try to install flotation to match the sinking parts. I put it between frames on the topsides under the ceilings and under the deck. I use polyurethane sheets cut to fit. I done care for the form in place stuff. I've used it. But, Don't like it.

Bill
Hi Bill, were you able to work out how much foam was needed to float your sinking parts, I guess it would depend of the weight of the polyurethane sheets to start with then if one sheet could displace 100 litres of water giving 100 kg of floatation I would need 7 sheets of foam tucked away to float the boat minus what ever the floatation of the wood in the boat, or if one cubic foot can float 25kg how much space would one need, It might be interesting to find out how much floatation is needed in foam to float lets say a 5.7 v8 with exhaust elbows, gearbox,prop shaft,prop and rudder as a base line.


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Bill Edmundson
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Re: Olds cool down

Post by Bill Edmundson » Mon Nov 16, 2015 6:37 pm

Fergal

The sheets that I get are 4'x8'x2". That is about 320 pounds per sheet or 50 kg., I think. Quick math, I may be off a little. It's the same flexible foam that you find in life jackets. I can get it in different thicknesses.

Bill
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Re: Olds cool down

Post by fergal butler » Tue Nov 17, 2015 1:25 am

Bill Edmundson wrote:Fergal

The sheets that I get are 4'x8'x2". That is about 320 pounds per sheet or 50 kg., I think. Quick math, I may be off a little. It's the same flexible foam that you find in life jackets. I can get it in different thicknesses.

Bill

So would that mean I would need 14 sheets or 4'x8'x24" of space filled to float the crackerbox.

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jenko
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Re: Olds cool down

Post by jenko » Tue Nov 17, 2015 2:19 am

Roughly you need 10 to make 1 cubic metre. if it is pe foam then I think it floats 93% of its displacement ,so given that the sheets are 1200 x 2400
10 will float 1 metric ton easily .V12 jag + vdrive and 72c trans with exhaust, propshaft and prop weighs in at 400 kg so you will probably only need 4.0 sheets not to mention the flotation foam you used in the seat cushions
Last edited by jenko on Tue Nov 17, 2015 2:22 am, edited 2 times in total.

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Re: Olds cool down

Post by fergal butler » Tue Nov 17, 2015 7:00 am

jenko wrote:Roughly you need 10 to make 1 cubic metre. if it is pe foam then I think it floats 93% of its displacement ,so given that the sheets are 1200 x 2400
10 will float 1 metric ton easily .V12 jag + vdrive and 72c trans with exhaust, propshaft and prop weighs in at 400 kg so you will probably only need 4.0 sheets not to mention the flotation foam you used in the seat cushions

Wow 400 kg seems very light, I going by this http://www.boattest.com/engine-review/M ... S-(220-hp) and that puts my engine at 946.00 lbs / 429.10 kg without the gearbox and other hardware, I guess thats because my engine is cast iron with cast-iron heads and manifold and yours is all aluminium.



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chugalug
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Re: Olds cool down

Post by chugalug » Tue Nov 17, 2015 8:20 am

:D Maybe you don't have to put foam in to cover entire weight of motor etc.since in the water everything weighs less(weight of motor- weight of mass of water it displaces)just looking at yahoo answers.things weigh less in water than in open air.I'm no genius just curious about it too cause I'm including foam in my boat.
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fergal butler
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Re: Olds cool down

Post by fergal butler » Tue Nov 17, 2015 8:28 am

You would also have the positive buoyancy of the wood not a lot in these skinned boats but maybe enough to float 100kg.


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Bill Edmundson
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Re: Olds cool down

Post by Bill Edmundson » Tue Nov 17, 2015 9:25 am

Wood's floatation value is a little less than 50% of the weight of the bare boat, no engine or hardware.

Bill
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jenko
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Re: Olds cool down

Post by jenko » Tue Nov 17, 2015 12:42 pm

Wow 400 kg seems very light, I going by this http://www.boattest.com/engine-review/M ... KS-(220-hp) and that puts my engine at 946.00 lbs / 429.10 kg without the gearbox and other hardware, I guess thats because my engine is cast iron with cast-iron heads and manifold and yours is all aluminium.
Dave lots engine and trans weigh 925 lbs/419 kg. 350chev and 71c (not sure but may have been pcm)

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