Lead thermometer

I'm after a lead thermometer for use with my Lee bottom pour and for ingot making from scrap lead (over a gas ring), and I'm looking for suggestions/options.

Need to keep an eye on temp for being able to repeat results when casting, and to avoid approaching zinc melting temp (when I melt down scrap I get quite a bit of zinc wheel weights. I know there are ways of sorting them, but I can't be fucked, and just floating them off the top seems easiest. Accidently going too high with the lpg ring is too easy, and having realtime temp reading will make this easier).

I had considered a high temp thermocouple like https://www.jaycar.co.nz/k-type-thermocouple/p/QM1282 for use with my home or work multimeter, but I dunno if it will stand up to an hour or two of use at a time. Cheap enough to just try and see, but if someone pipes and says " Yeah nah fuck that", that's a bit of time and coin saved init?

One of those long probed thermometers with the disc shaped dial at the top seems to be the go, but I can only seem to find them in lower temp ranges, ie for cooking etc.

What do you fellahs use?

You could try an infrared/laser pointing thermo?

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Originally Posted by inglishill

You could try an infrared/laser pointing thermo?

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Yes, possible, but with both hands busy when casting, it'd nice to have a constant readout

A type J would probably do the job. Type K easier to source probably. You just need a suitable thermocouple pocket to hold it.

Optically with hand held may struggle with the varying emissivity of the molten surface i.e. sometimes clean after fluxing, sometime skummed over with doss.

Depends on how accurate you wish to measure.

The main thing is to avoid getting to 900 deg F/482 deg C.

I used to be pretty slack when casting, usually overheating to hell. Also a bit slack with good ventilation. Still alive though.

Just looked thru my Lyman book – thought there might have been a pic of a suitable thermometer there.

https://www.amazon.com/Lead-Pewter-B.../dp/B0026Q6GE0

With out googling, what's the issue if you get zinc melted in?

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Originally Posted by Beaker

With out googling, what's the issue if you get zinc melted in?

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A big mess and fucks your pot

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Originally Posted by zimmer

https://www.amazon.com/Lead-Pewter-B.../dp/B0026Q6GE0

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Yep that looks the go, although NZ$67 + freight owie

Also remember that zinc fumes will def have you puking your guts out. Ask any welder who's welded galvanised material.

just stick your figure in it to see if its melted :thumbsup:

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Originally Posted by northdude

just stick your figure in it to see if its melted :thumbsup:

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If it hurts it's hot!!
We used to drink milk to soak up galv fumes!

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Originally Posted by SiB

Also remember that zinc fumes will def have you puking your guts out. Ask any welder who's welded galvanised material.

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Been there done that got half a tshirt

@Tommy

Aliexpress is your friend :thumbsup:

https://www.aliexpress.com/item/XH-B...2-ab1c848f9f9a

https://www.aliexpress.com/item/PEAK...0-36ad5ffc0431

Cheers
Pete

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Originally Posted by P38

@Tommy

Aliexpress is your friend :thumbsup:

https://www.aliexpress.com/item/XH-B...2-ab1c848f9f9a

https://www.aliexpress.com/item/PEAK...0-36ad5ffc0431

Cheers
Pete

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Out-fucken-standing!

Just ordered one

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Originally Posted by Tommy

Out-fucken-standing!

Just ordered one

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no worries :thumbsup:

Cheers
Pete

Tommy, tommy, tommy, tommy, Tommy, tom Tom. Mate there is 90 some degrees C worth of difference in the two melting points. That means when the Lead has melted the Zinc has not. Can't you tell the difference between liquid and solid? (Start thinking the difference between the water in the dunny and the poop that is floating on the top). When the lead has melted scape the solid dross that is floating on the top off and Bob's your Nana. Alternately, 419.5 degrees C (the melting point of Zinc) is enough to make your foreskin sizzle so you could drop your old fellah in the pot and as long as it is not sizzling then the Zinc should still be solid.

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Originally Posted by Tommy

Out-fucken-standing!

Just ordered one

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@Tommy Which one did you go with?

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Originally Posted by Rushy

Tommy, tommy, tommy, tommy, Tommy, tom Tom. Mate there is 90 some degrees C worth of difference in the two melting points. That means when the Lead has melted the Zinc has not. Can't you tell the difference between liquid and solid? (Start thinking the difference between the water in the dunny and the poop that is floating on the top). When the lead has melted scape the solid dross that is floating on the top off and Bob's your Nana. Alternately, 419.5 degrees C (the melting point of Zinc) is enough to make your foreskin sizzle so you could drop your old fellah in the pot and as long as it is not sizzling then the Zinc should still be solid.

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Yes but sometimes you just like to keep an eye on things, and know where you're at. Hence I didn't want a million dollar unit. While I was looking for one I found a donut hole gauge set, I'll spring ya a set ;)

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Originally Posted by zimmer

@Tommy Which one did you go with?

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Went with the ten bucka one off our chinese mates. Have an account, so it was just a matter of hitting "yes please"

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Originally Posted by Tommy

Yes but sometimes you just like to keep an eye on things, and know where you're at. Hence I didn't want a million dollar unit. While I was looking for one I found a donut hole gauge set, I'll spring ya a set ;)


Went with the ten bucka one off our chinese mates. Have an account, so it was just a matter of hitting "yes please"

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@Tommy

That ones actually almost $16 nz pesos

But free shipping to this mans Banana Republic. :)

Cheers
Pete

The Zinc wont mix in with the lead but will form an oatmeal like appearance on the top even if you do overheat the lead. Drop the temps to normal and scoop the dross off. Reflux with grease or wax or whatever to reabsorb the tin and antimony and your good to go.

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Originally Posted by zimmer

@Tommy Which one did you go with?

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@Tommy interested to know the outcome. Have you received your bits?

Casting bullets demands experimentation. Out of interest I once tried casting a load of zinc projectiles because id read that you could push them at jacketed speeds. Takes much more effort than lead to do and the results were generally terrible the mould cooled too fast giving a wrinkled finish unless you were super quick. The finished articles that weight 180 in lead only weighed 120 ish in zinc. They shot ok from memory and didnt need lube. But i went back to lead and gas checks, and now even the gas checks are history.

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Originally Posted by zimmer

@Tommy interested to know the outcome. Have you received your bits?

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It arrived on Friday, haven't had a play yet

Tommy ........ how did the aliexpress thermometer work out with your casting