Lead Ballast

[mylo]

All,

I wish I could lay claim to this idea, but I can't. I read it here somewhere but thought I would touch briefly on it again.

I just bought 200lbs of used lead wheel weights from my local tire repair shop for $40.00. That's a 5 gal pail about 2/3 full of these things. The tire guy said that a few years ago, he used to give them away, but now with lead being difficult / a hassle to get due to health concerns, he's got all kinds of guys who reload ammunition or make fishing lures coming to him asking for them, that he decided to make some money. When I told him I needed it for lead ballast in a submarine.....I got a blank look. None the less, I feel that $40 for 200lbs is pretty good. No shipping, no handling, no questions.

Mylo

[tmsmalley]

Besides tire weights and lead

Besides tire weights and lead roof flashing, duck decoy strap weights, available at your local Bass Pro Shop, Cabelas or other shooting sports shop are great and a lot cheaper than the little lead "cubes in a row" you buy at the hobby shop. You can bend them to shape by hand and cut them to length with tin snips.

[KevinMC]

So far I've been lucky

So far I've been lucky enough to be able to finnagle all my used tire weights for free, but maybe that ship will be sailing soon. Regardless, what ever the source of lead you use, if the shape you have to work with doesn't suit your needs lead can easily be melted down and poured into molds to make it what ever shape suits your fancy. I have an old stainless steel pot and a propane one-burner camp stove that I use just for this purpose. (Be very careful about the fumes when doing this, and definitely do it outside!) Molds can be as simple as a tin-foil lined wood box... YMMV

[bigdave]

I have been using 1/4"

I have been using 1/4" lead wire I got from Mcmaster Carr. It came on a 5LB spool. BD.

[Larry Kuntz]

Hey Dave, on the same

Hey Dave, on the same note, why not electrical solder of the non flux type (though I don't think the rosin flux would hurt anything). It is 60/40 tin and lead, and in many sizes (diameters). I think it would work especially well for trimming. Very small pieces easily formed around internal areas.

[mylo]

Kevin,

Yes, these used wheel

Kevin,

Yes, these used wheel weights "used" to be freebees, but no longer. Too many cheap skate hunters and fishermen (and now a sub guy) lurking around tire shops I guess.

So a stainless pot of some sort works well for melting ? What do you use for breathing protection ? Do you think just your average paint mask (not just one of those little dust mask things) would do ? That little propane stove thing is a good idea. I was going to use a torch, but I like that idea better.

Mylo

[KevinMC]

Hi Mylo,

I originally started by

Hi Mylo,

I originally started by melting weights using a propane torch, but it too easy to put all the heat in a small portion of the pot- making for only one place that the lead would melt well and I was afraid I'd eventually burn that spot out. Besides, with the propane stove you don't need to hold the pot while you're throwing more lead into the brew and trying to stay up wind... (When melting tyre weights I hold onto the weight's clamp with a pair of pliers, dip the end of the weight into the pot and allow the lead to fall/melt off the clamp. They're also useful for pulling the slag that accumulates on top of the molten lead)

If there's a good enough breeze sometimes I'll just stay up wind, but if the air is still I grab my paint mask.

KMc

[jeffrey j]

....

hey guys,
I used lead shot in all my subs, its small beads will fill in the areas in your hull perfect, , my first sub I mixed in resin to hold it in, big mistake but it worked fine. Then I started using plastic sandwich bags to hold it and it will still form to the shape of the hull. Any gun store will sell you this by the bag. Jeff J.

[cstranc]

I used diving weights. I

I used diving weights. I think it was around $2.00 for 3lb. Not as good as Mylo. I borrow my Dad's induction heater to melt the lead then pour it into molds.

Been doing that in the basement though. All this talk of working outside has me thinking that's what happened to my coordination and IQ...

I find if you make really large weights you have to plan for the thermal expansion & contraction when you build the mold. Remember it's going to expand the most in the longest direction, so allow for it, or else the mold will buckle and twist.

[mylo]

Chris,

Good point on the

Chris,

Good point on the mold. I plan on pouring the lead into square steel channel and then using the entire thing as my ballast weight which will fit nicely in the keel. I'll make sure I don't fill it to the top though. Thanks for the pointer, or I would have. Wait a minute, wouldn't it be expanded as much as it's going to be when it's in melted liquid state ? so in effect, it will shrink after it cools in the mold ? I know a bunch of gun guys who reload and they always melt indoors........mind you......they are all messed up too.......I doubt it's a coincidence

Mylo

[tmsmalley]

You can make a good

You can make a good mold by creating your lead shape from clay, make a mold of the clay from plaster of paris (get it at a good crafts shop), pull the clay out once the plaster sets, and pour in the molten lead.

I used to make fishing jigs that way and it works great! The hot lead doesn't deform the plaster.

[mylo]

Tim,

Are you one of

Tim,

Are you one of the aforementioned "cheap skate fishermen" that lurk around Tire Shops for those used wheel weights ?, or are you over that silly fishing hobby and now just do subs ?

Mylo

[cstranc]

Just so you don't make

Just so you don't make the same mistakes as me.



This is the induction heater and mold I was using. Funny I'm sure dad uses it for making fishing weights too. So many of those fishing people out there. There must be a more R/C way to disturb fish...

You can see the aluminum sheeting I was using to create the inside of the mold. If you look carefully you can see a brass tube going through the center of the form. That's for a lead screw so I can shift the weight dynamically to re-trim the Sierra as she goes.

I thought I was ok with the thermal expansion because the ends of the mold were held in place by elastic so they could expand...

So the one thing I did learn from pouring lead weights before. Don't just barely melt the lead then it sets so quickly that it creates a very un-even surface. The other thing was to soak the mold in water so it's not as likely to burn...



That is what it looked like after the pour. The two ends came out quite nicely. But in the middle the aluminum buckled due to the thermal changes. The other interesting thing. That brass rod I mentioned. Well the temperature caused it to bow upwards in the center. About 1/32" deformation.

Being a safety conscious group I just have to say. When I saw the aluminum start to buckle I started to thing of all sorts of things to do to try and fix it before it set. But I left it. I have a huge respect for the type of burn even the smallest drop of molten lead would cause. It's not worth playing around with. Let it set as-is. If it annoys you enough melt it down and do it again.

Working with large quantities of lead there is a lot of heat involved. As I mentioned the wood was soaking for 2 hours prior to the pouring and it dried out, then started to smoke so I was dropping water on it as the lead was cooling down.

I used thin aluminum sheeting for the form so I could get a contour that matched the bottom of the hull. Next time I shall use aluminum L that are 1/16" so the don't deform like that.

Working with smaller weights sound like more fun that pouring big things. It's probably a whole lot easier to trim later being able to add a little here and there. But then I guess you plan to have main ballast weight, and separate small trimming weights.

[mylo]

Chris,

Your lead ballast pour

Chris,

Your lead ballast pour looks exactly like something I would do.....in other words, screw it up the first time.

What I have planned for my lead ballast is going to be very easy, just pour the molten lead into a piece of square steel channel that has an end cap on it. This lead filled piece of steel will then be stuck using magnets, so that I can adjust it, to a piece of flat iron that I'm using as a keel base plate, which in turn is screwed right through the bottom of the fiberglass to a flat iron keel skid plate that I put on in case I run 'er a ground, or just drop the thing on a table or something. It's a heavy duty setup and should take considerable abuse.

Would the magnets in this setup cause any radio or electronics interference ? If so, I guess I'll try velcro, which might be better anyway.

Mylo

[sailman58]

Casting Lead

Water and liquid lead (or any molten metal) do not mix well! The usual result is a loud bang as the water flashes to steam followed by a spray of molten metal. All parts of a mold should be bone dry. The wood can be treated with waterglass which I think is sodium silicate.