Internal Ballast - to melt or not to melt

[double u]

Originally Posted by Sailmonkey

I would be all for melting it, but then your left with the question of how to shape it to the keel. You can’t very well pour molten lead into a fiberglass keel.

I seem to recall that (a good while ago) some krauts did just that (with the boat in the water) & it only damaged the innermost layer of the fiberglass (how they knew I don't remember)

[Cadence]

Originally Posted by DavidSaunders

Thanks again to all for sharing your thoughts, insight, experience, wisdom and concerns.

I just did some "digging" and discovered a large chunk of what also appears to be lead (at least by flashlight)- it was soft and shiny inside when I poked at it with my pry bar. Maybe this is just fill around the main pieces.... More digging is obviously in order.

I took about 1500ml (I know, but that's what the measuring cup uses for units) of lead pieces out, and was able to use about 600ml of water to fairly cover the lead.
So if my math is correct it is a little over one third by volume of airspace right now. Is it right then, that I could reduce the size by about 1/3 if it were all melted? The draft on Theodora is about 5'8", so I'd guess the keel to be about three feet deep.

What I initially thought was some sort of string in the mix are in fact short pieces of metal, which may also be lead. More investigation all around, it seems. I just thought I'd give you an update.

I'll continue to keep you posted.
Thanks Again,
DavidSaunders

David,
You may wand to make a wooden plug that fits and make a sand casting from it or them if you made multiple plug shapes to account for the change in keel shape. Doing several layers might make it easer to install weight wise
Roger.

[evm1024]

At some point I will be adding 1000# of lead shot to the bottom of my bilge. I'll mix this shot with epoxy to hold it in place and then glass over it. I do also want to raise the top of the ballast (damn, the bilge is just too deep) so I'll likely put a layer of foam on top of the glassed in lead shot and then glass over that.

One reason to just use shot is that I will be able to get the 1000# of lead shot in a slab that is about 5.5"" thick. By using cast lead ingots instead I could get the lead in a sheet (assuming I could pour it in the keel) that was about 4.25" thick.

The difference in the position of the center of mass between shot and cast lead the center of mass is about 5/8". (1/2 of 5.5" = 2.75" vs 1/2 of 4.25 = 2.125" )

So, in my case the change in righting moment between shot and cast is only 5/8". Not worth the effort for me to melt and cast the lead.

From the photos it appears that the lead bullets in your ballast are not copper jacketed (that is good) and thus the decrease in density of your ballast is caused by impurities and trash in the mix.

Melting would certainly get rid of those impurities and thus lower the center of mass of the ballast. But just cleaning them up and setting them in epoxy may also get you most of the way there.

If in the case like me you have a large area (mine is 4' by 1') to place the ballast then the change in density only lowers the center of mass slightly.

On the other hand if you have a much smaller area to place the ballast then the increased density may lower the center of mass significantly. Lowering the center of mass by 6" for example would be very significant in a boat with a 4' draft.

Choices, but you can do some math to see what the advantages are.

[Cadence]

Originally Posted by Cadence

David,
You may wand to make a wooden plug that fits and make a sand casting from it or them if you made multiple plug shapes to account for the change in keel shape. Doing several layers might make it easer to install weight wise
Roger.

However, I'm still in the camp of if it ain't broke don't fix it. I have no idea how much but it sounds like stiffening your boat. Don't she need that?

[StuM]

Are you sure those projectiles are lead? They don't look deformed enough to have come from a range if they are just lead. Try cutting up a few to see if they are jacketed projectiles.

[Steve Bean]

Unjacketed bullets fired into sand can end up with practically no damage. The jacketed projectiles I have experience with have a shell of copper. This would be easy to see; I don't see it in these pictures. I would dig much deeper to find out how many big chunks of lead are in the mix. The more and the bigger they are, the less volume is being lost to air space.

[Cadence]

Originally Posted by Steve Bean

Unjacketed bullets fired into sand can end up with practically no damage. The jacketed projectiles I have experience with have a shell of copper. This would be easy to see; I don't see it in these pictures. I would dig much deeper to find out how many big chunks of lead are in the mix. The more and the bigger they are, the less volume is being lost to air space.

Most people going to an outdoor range with a sand backdrop aren't shooting jacked bullets. Lets make sure we kill the sand after our paper target. I'll bet most are wad cutters or hard ball, just lead.

[a64pilot]

I’d say due to the required lower velocity, and the fact that factory non jacketed bullets are rare, that the majority of rounds fired anywhere are jacketed.
However from the picture there seems to be what look like strings or something? I have no idea where the projectiles came from, but speculate that maybe they were not fired, cause even shooting into sand usually does deform them to some extent.
Plus as has been said, bullets, tire weights etc, are not pure lead.
Also as has already been said, you won’t believe how much dross or trash you will get from this stuff once you melt it. What are you going or do with all that hazardous waste?
Take a small steel can and melt some and see. You can melt lead in a steel can, with a hot plate.

[DavidSaunders]

Thanks again for your replies everyone. I am still learning as I go here. I went to buy another sailboat tonight, for parts, so didn't get to melting this stuff.
A64Pilot, I though they were strings, too, but it appears to be metal. Very flexible. The rounds appear unfired. It could be that they were surplus to someone's needs.
The original owner is a Navy vet, but his memory is going, so I didn't press him on it. I was just glad to see it was lead and not scrap steel....

[DavidSaunders]

I cut the tips off these bullets to check hardness, and scratched the wire for colour. It all looks the same to me, but then I'm a little colour blind.
David Saunders

[frozenhawaiian]

I'd melt it into bricks personally, actually easier to get in and out if you need to again.

[Steve Bean]

If the bullets have been fired, they will have rifling marks, caused by the spiral grooves in a gun barrel, that make the bullet spin so it flies straight. Forensic investigators can use these marks to tell if a bullet has been fired from a certain gun, because there are slight differences from one gun to another. If any of these bullets were copper jacketed, it would be obvious even to a color-blind person.

[DavidSaunders]

Well, further investigation reveals that they beat me to it. It's already bricks of lead. It may not show up well in the picture, but it cut easily with the knife and revealed a shiny interior. Now onto the fun of removing them for dry out and repairs....
Thanks again for all of your responses.

[hellosailor]

"Most people going to an outdoor range with a sand backdrop aren't shooting jacked bullets. "
Except, I've been to ranges that either had a large sand berm in back, or were simply on a sand quarry's floor. And folks were using military surplus rifle ammunition, which is commonly copper jacketed.
So lots of the cleanup was and will be copper jacketed. Very different from plain lead in hunting rounds or unjacketed handgun rounds.

I'd vote in favor of melting the pot metal and skimming the dross, IF you could be happy with not setting the keel skin on fire, and IF you could be happy about hot breathing lead vapors, and IF the magnitude of the task wasn't all an issue. Melting a thousand or two pounds of lead is going to be a long job, unless you do it foundry style, using a cast iron bathtub as the crucible and some huge gas torches to get a continuous melt and pour. And of course, you can add in some lead ingots once there's a puddle in the keel.

There's a dangerously hypnotic quality to molten lead, it looks clear and cool like water, inviting you to touch it. Which of course, is not a very good idea.

[CarlF]

I think the center of gravity improvements will be minimal. I don't think it's worth the time or the very real health dangers of working with lead. "The perfect is the enemy of the good"

Using resin is safe, easy, and avoids any future moisture problem.

Shannon did this using cast lead pieces that are sized and fit into the keel cavity and then casting resin is poured in until it's above the level of the lead.