Lead keels are the best
- Thread starter sailorman
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Dan Tribe
Well-Known Member
That's quite an undertaking. It looked well thought out, presumably they had some expert advice.
I was surprised that a plywood mould would work.
I was surprised that a plywood mould would work.
DownWest
Well-Known Member
Ply or plank moulds are often used, sometimes coated with silica glaze. The melting point of lead is only enough to scorch the wood, not set it on fire.
I am about to do a (small) one and will use pine shuttering planks.
vyv_cox
Well-Known Member
When I was a young lad I fitted sails to four-wheel pram-based carts. With no access to any real metalworking facilities I made mast steps by bolting brackets to an outer tube with an inner tube to hold the mast, held in place by casting lead into the annular space. The hole at the bottom was bunged up with plasticine. This held the molten lead perfectly well until it set.
Motor_Sailor
Well-Known Member
The ply will work, but delaminates and falls apart as they found out. Traditionally it was solid lumber. It also wasn't very dry - you could see steam bubbles coming up all the time. I should think that will be like an aero bar when they're done. I'm glad it's just a simple lump of lead they were making to go on the bottom of a wooden boat.
Concrete works well as a mould as long as it's set into the ground and you leave it to dry properly. We built the moulds in steel as that's what the yard was skilled in.
The overriding thing to remember with these schemes is the amazing weight of the lead and the fact that everything, including steel fittings, will float to the surface. In the first keel we built, I tried to incorporate the keel bolts as a large stainless steel preformed structure that went way down into the lead. It weighed a ton, but the supports weren't strong enough to hold it in place and the whole thing slowly bobbed to the surface of the molten lead. Had to start again.
They also had some very variable respirator standards, with a couple who were stood quite close wearing none at all. The fumes and dust go a long way and feeling unwell after a day pouring lead, is one of the conditions that the hospital emergency rooms in the States, have to report to OSHA if the casualties had been 'at work'. Within 24 hours you'll have your yard crawling with inspectors, who swab everything within a 150 yard radius. Even if they find the merest hint of contamination on the coffee machine, you get hit with a quarter of a million dollar fine. Made quite a dent in that year's figures.
Concrete works well as a mould as long as it's set into the ground and you leave it to dry properly. We built the moulds in steel as that's what the yard was skilled in.
The overriding thing to remember with these schemes is the amazing weight of the lead and the fact that everything, including steel fittings, will float to the surface. In the first keel we built, I tried to incorporate the keel bolts as a large stainless steel preformed structure that went way down into the lead. It weighed a ton, but the supports weren't strong enough to hold it in place and the whole thing slowly bobbed to the surface of the molten lead. Had to start again.
They also had some very variable respirator standards, with a couple who were stood quite close wearing none at all. The fumes and dust go a long way and feeling unwell after a day pouring lead, is one of the conditions that the hospital emergency rooms in the States, have to report to OSHA if the casualties had been 'at work'. Within 24 hours you'll have your yard crawling with inspectors, who swab everything within a 150 yard radius. Even if they find the merest hint of contamination on the coffee machine, you get hit with a quarter of a million dollar fine. Made quite a dent in that year's figures.
Joker
Well-Known Member
I used to melt lead as a boy [bullets retrieved from the sand at the school's rifle range]. In health terms, pouring molten lead like that strikes me as distinctly hazardous. Lead doesn't get eliminated from your system easily.
lw395
Well-Known Member
Molten metal lead is fairly safe, compared to lead compounds, in terms of poisoning.
If the metal has a lot of corrosion or other compounds on it before melting, these are far more likely to get into your system.
Damp moulds are a very bad idea as the steam will spit particles of lead compounds a long way.
Obviously the heat contained in tonnes of molten metal is something that can do serious damage.
I've cast a few small things, but I wouldn't video it and I take at least basic precautions to keep the fumes contained and away from me. Same as I do for soldering these days.
alant
Well-Known Member
IIRC 232 deg C.
DownWest
Well-Known Member
Bit more.. 327°C
STOL71
Well-Known Member
Lead keels are the best!
I would go as far as saying that I'll only sail longkeelers with encapsulated lead keels.
I would go as far as saying that I'll only sail longkeelers with encapsulated lead keels.
jwilson
Well-Known Member
Encapsulated is good if you are worried about keels dropping off, but loses the ability of an external lead keel to cushion the impact shock of a grounding on rock. Just an inch or so dent on the leading edge of a lead keel massively reduces structural damage to the hull compared to the same impact with an iron keel that has no "give" at all. Also dry out an encapsulated keel on a rough hard base and you can damage the GRP.
