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[merseyferry]

once again gents i am hopeing you can help me..whats the best way to get a  32 inch (L) by 5 inch (h)  large hull....hulls waterline.also  what is best to waigh the boat down to waterline i was considering   old batterys ,or  some lead??? any sujestions would be apreciated regards pad

[Buccaneer]

Hello Pad
You can use old Lead Acid Batteries but they come at a fixed size, shape and weight. I find they have an average specific gravity of just under 3, i.e. 1 cubic centimetre weighs 3 grammes. Try lead shot, available from any good gun shop, which works out at 8.5 grammes per cubic centimetre or lead flashing from a builders merchant which is about 11 grammes per cubic centimetre. The advantage with lead shot and flashing is that they can be fashioned into any shape and size to fit your boat. I find Lead shot is best put in small plastic tubs, or make your own wooden boxes, and then seal them well.

John

[tigertiger]

Another trick with lead shot, add them to epoxy or other resin aim to only just coat the lead with resin, mix it well, and maximize the amount of lead in the mix. If this is done in a poly bag, it can them be pushed down into the bilges where it will set in the form of the hull. These shaped bricks are then easy to remove and re position for transporting. However, you do need to know where you are going to place them before you start, to trim the boat correctly. Some trimming can still be achieved later with smaller additional loose weights.

[Plastic - RIP]

You can approximate the submerged volume of the hull into litres and, as water is 1kg per litre, you can get a good idea of the extra weight needed to get it down to the waterline.

I use lead sheet from roofing suppliers - it's soft, flat & can be cut with scissors into whatever shape you want and then stuck right into the very lowest part of the hull with a dab of silicone.

The centre of gravity of batteries can be well away from the bottom which can raise your C of G and possibly destabilise shallow-draft boats.

[merseyferry]

many thanks gents  usefull infomation once again   

[kinmel]

You can buy very fine lead shot that has a density of about 6.8kg/litre from www.theleadweightcompany.co.uk/lead-shot-ballast.html

Price is £4.65 per Kg. inc P&P.