Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Working Vessels => Topic started by: 6705russell on July 27, 2009, 11:43:18 am
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Has anyone built ballast tanks in their larger models to get it down to the waterline? Any info/ideas on materials used would be appreciated...
Thanks
Russ
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Build your tank first. You can make this from whatever material you like,but plastic or GRP would be preferable, and I would choose the later as you can mould it to the shape of your hull which should enable you get the lowest centre of gravity.
Fit a schraeder (tyre) valve to the top of the tank, and ensure the tank is vented at the bottom and exposed to the water surface. A few small(ish) holes should be sufficient to allow flooding. To fill the tank, depress the valve, and the water should start to flood the tank.
To empty, just connect a small air pump (i.e. a bicycle pump) to the valve,and blow the water out the way it came.
if you don't want to drill holes in your hull, then you will need to use a water pump of some description.
A centrifugal pump will shift water at the highest volume, but you will need two, or a valve arrangement, as the these pumps are not bi-directional. A geared pump will pump either way, but they are a lot slower.
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Russ
Have a look at the build log for Blue Marlin Semi Submersible ship - I used a combination of free flooding and pumped ballast tanks.
Ian
http://www.modelboatmayhem.co.uk/forum/index.php?topic=9014.msg87341#msg87341 (http://www.modelboatmayhem.co.uk/forum/index.php?topic=9014.msg87341#msg87341)
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Russ,
One of our club members pumps watewr in and out of his Chant, people think its sinking.
I can email his name he will tell you how he did it.
I was thinking of plastic water bottles with pumps for in and out working from tranny
Les PMBC
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Thanks Les,
Sorted now using home-made acrylic tanks and pumps :-))
Russ