Lead / Pewter Casting at Home

Intro: Lead / Pewter Casting at Home

How to cast lead / pewter at home using what you have around you.

I needed some lead balls for using in a homemade ball mill and they are too expensive to buy and I had some lead kicking around in the shed so I figured I would cast my own.

At this point it is worth noting that lead is poisonous so be careful.

you can cast pewter in the same method as I have shown for the lead.

STEP 1: What You Will Need

what you will need

----------------------

some lead, I used roofing lead off cuts

plaster or other casting media

non-drying modelling clay

old tin can

biscuit tin or somewhere to put scrap molten lead

an old teaspoon

long handle pliers

1 x G clamps

a shallow muffin tin or somewhere to put excess molten lead

hacksaw or tin snips to cut off excess lead

old scissors for cutting lead

petroleum jelly

STEP 2: Making a Mould

I need a mould for pouring molten lead in to unfortunately the best thing for this is a metal mould but they cost money unless you have a home foundry to cast your own. I decided that I would use what I know and make it from plaster which I had kicking around.

using my non-drying modelling clay I made a ball of roughly the right size, then made a rough cone which will form my sprue.

I cut it in half and lay one half on my desk.

Make a small ball and cut that in half and place the 2 halves on either side of the part to be cast, make them staggered, these will form our key for the mould making sure it will only fit together in the correct way and aligned correctly.

using the modelling clay build walls all the way round the part but make sure the bottom of the cone/sprue is butted up to one of the walls.

mix up your plaster to the consistency of thick cream, only mix up enough for this half of the mould, pour this in to the mould all the way to the top of the walls.

Agitate (shake gently) the mix to dispel any bubbles.

let your plaster harden then remove the walls and turn the mould over.

remove the small ball parts we used for the key, and then using a hobby knife carve off the edges of the key points so there's no overlap.

now place the other half of the part on top of the one in the plaster, line it up and push down lightly to make it stick.

now build walls again high enough so they come above the highest point of the part.

coat the plaster and the 2nd half of the part in a thin coat of petroleum jelly, this will act as a release agent and stop the plaster sticking to its self so we can separate the 2 halves.

now mix up some more plaster and pour it in to the 2nd half, agitate again and then wait for it to harden.

once its hard remove the walls and separate the mould, remove the clay from the mould.

now you can wait for a couple of days for the mould to dry out or you can cheat, pop the 2 halves on a baking tray separately, pop in a cold oven then put the oven on low and leave for a few hours to get the water out the moulds.

do not cast with wet / damp moulds, they will crack/crumble or explode.

STEP 3: Prepare Your Lead

while your mould is in the oven you can prepare your lead

I'm using roofing lead off cuts so it's easy enough to cut up with some old scissors.

you need to make small pieces so you can gradually fill your crucible (tin can)

STEP 4: The Melt

take your tin can and squeeze one end so its pointy, this will be your pouring spout.

pop your can on the small ring of your hob on high heat, pop about 5 or 6 bits of lead in.

your can will smoke to start with as it burns off the coating inside the can, this will stop after a few minutes.

important note here, do not put too many pieces in at once you will freeze the melt, e.g. it will solidify and take a while to melt again.

slowly add up to 4 pieces at a time, waiting for each batch to melt before adding the next, you can check if they are melted by poking the pieces you have put in.

don't put too much lead in your crucible otherwise you may not be able to pick it up safely. only melt what you need maybe a little more to be sure you have enough.

once all your lead has melted, leave it for a few minutes to super heat, this will give you extra time for your pour.

using your spoon, bend it so you can get it in the crucible, hold it with the pliers and skim off the debris floating on the top this is known as dross. tap your spoon in the biscuit tin to get rid of the dross.

to pick up the crucible use the long pliers.

those who have done casting before might be tempted to put in salt to help as a flux, don't do this it produces too much gas, don't put anything in the metal its fine without it.

STEP 5: The Pour

if your plaster mould is cold, warm it up gently in the oven, this will help protect the mould somewhat from thermal shock. e.g. it shattering, or exploding.

do your pour outside for safety.

hold your mould together using a clamp.

pick up your crucible and take it to your mould, put it down next to your mould and adjust your grip so you're ready to pour.

pour slowly in to your mould, it should be a steady trickle, too fast and the air inside will bubble and splash lead everywhere and create gas pockets.

make sure you fill your mould up to the top of the sprue, this is important as when the metal cools it will shrink this sprue will help feed the mould making sure you don't get dips or voids.

once you have filled the mould return the crucible to the hob and turn the heat down, you just want to keep it liquid, you can turn it back up when you want to add more lead.

wait for a few minutes for the lead to cool in the mould, you can then release the clamp and remove one half of the mould.

using the pliers grab hold of the sprue and wiggle the cast and it should release.

STEP 6: Finishing

Now all that is left to do, once they are cooled, is to tidy them up.

using a hacksaw or some tin snips cut off the sprue as close to the part as you can.

using a file clean up the edges and the cut where the sprue was.

you can pop the sprue you cut off back in to the crucible.

if you have finished casting pour the remaining lead in to the muffin pan to form an ingot which can be melted down the next time you want to cast something in lead.

Comments

[LoïcB4]

How many uses did you get out of that mold?

[PamBensman]

I have about 50lb.s of pewter plates. They are scratched beyond saving I was wondering if I melt them, could I use them for making jewelry?

[BenB346]

I read an article that said it's not safe to have lead around your arm and neck on a daily basis or to even eat off of them like silverware.

[RiddlywalkerB]

yes- our art college was buying battered old pewter mugs as it was a lot cheaper than buying 'new' ingots.

I am concerned by the use of plaster moulds on this page- ANY moisture in the plaster and the hot metal will splatter all over the place when it hits and makes steam- 'warming the moulds' is not enough. traditional bronze moulds were plaster and crushed ceramic (brick?) baked for 24-48 hours to melt out the wax and properly dry the mould, lead and pewter can now be safely cast in high temp silicone- which means you can do a run rather than single objects.

Melting lead? well ventilated space, fume mask if you are doing this regularly, always wear Eye Protection- stupid not to?

[n1cod3mus]

I can't see why not, you could make molds out of plaster, as long as you heat the molds before you pour they should come out well.

when you have done some post them up here, it would be nice to see.

try a bracelet you could do that flat then bend it to shape afterwards should be nice and easy.

[BenB346]

This isn't pewter this is only lead remelted and repoured. Unless I missed another element that you used in it?

[ak47freak]

would it be possible to pre-heat the mold in an oven/toaster oven to try and reduce the effects of heat shock?

[n1cod3mus]

thats exactly what i did when i started but between casts it cooled too much, i should have put it back in the oven betwen casts

[RiddlywalkerB]

the 'frog' of a house brick makes a fantastic ingot mould- you can pour them shallow for small amounts..... never any problem with sticking, and they hold the heat well.

[johnathan2520]

I appreciate your will in teaching these things to us. My problem is different: I have to make a mold to cast lead from a piece I can not duplicate or make myself. It's a rectangular piece (1X1X4" long), that has two 'rings' around itself, made out of steel. Do I need to make a plastic or clay mold out of it?

Thanks,

john

[n1cod3mus]

Hmmmm, well you would need to make a mole that flexible, so I would use silicone to make a block mold of the original probably a 2 part mould. Then pour hot wax in the mould to make a wax copy. Using that you can use a technique called lost wax casting. Coating the wax in plaster letting it set the. Slowly heating it to melt the wax out. Then you can pour lead in that, break the mold to get the part out.

[Tavistock]

I joined specifically so I could post on this instructable because I have some questions.

1) I assume since I didn't read it in page five that you didn't use a release agent when you poured the lead into the mould, is that correct?

2) I plan to use your instructions to make open faced press moulds for moulding bases for the game Battletech. The bases are just flat hexagons roughly an inch and a quarter from any two opposing flat sides. I would assume I would just replace your half ball and half cone with one or more of the bases for the game, pour in the plaster as per page two, then follow the rest of your instructions?

3) Is there a specific kind of plaster I should be looking for?

Thanks so much for all the inspiration thus far.

[n1cod3mus]

no release agent, if you are pouring just hexagons you could probably just use half a mould. plaster wise, it depends on how many casts you want really, but almost any will do but you want to make sure its really dried out before using it otherwise it will crack.

any reason you are not using a silicone mould and pouring it with liquid plastic? probably be cheaper.

[Tavistock]

Mostly because I have two full lead sheets (about 25 pounds or so each) and around 15 to 20 pounds of pewter/lead/palladium/raladium sprue and shavings from miniatures that I'd like to make use of, and I prefer the weight of metal bases for the larger minis, though your idea of silicon moulds and plastic bases for lighter minis would probably work well.

[WilliamK38]

I know this is a while after you posted this, but two questions. 1) what kind of table did you use when pouring your plaster mold? I've never worked with plaster before and I don't know if "sticking to the table" is something to worry about or not. 2) I have a Coleman two burner camp stove...will that really be hot enough to melt pewter? I know pewter has a melting point close to 500 degrees F, and people in the chat say a camp stove would work...I just didn't realize camp stoves got that hot. Thanks.

[n1cod3mus]

if you are worried about your table just put some plastic down or put it on a plastic board or glossy piece of card.

yes a camping stove would be fine.

[sachinp7]

i studying about lead casting,, nd cast from lead acid baterries,,we can produce upto 95% of lead from an baterry but the problem is antimony and salenium,,how can i reduce these two element..both have high melting point than lead,,if we are going to reduce antimony so lead will ixidised ,,and either going to cast lead,,,so the recovery in only 60%,,,so what can i do,,,

pls help me,,to figure out the problem,,

[Fardenco]

I know it has been a long time since you asked this, but whatever.

Antimony's melting T° is about 630°C, and lead melt at just 330°. So if you just heat your thing between these 2 temperature, you'll be able to isolate the lead (liquid) and the antimony (solid).
I hope I help anybody =)

[n1cod3mus]

Honestly, i have no idea, I didn't study chemistry at school :-( probably best to google it.

[dragonthc]

could you use silicone as a mold? It's supposed to have heat resistance up to 700º F