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  1. #1
    BobL is online now Member: Blue and white apron brigade
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    Default Casting small amount its of brass

    A family member has picked up about 30kg of brass (0.22 used rifle cartridges) from his gun club and wants to experiment with some small brass castings. He only has a small charcoal forge and couple of small (120 mL) graphite crucibles. He knows about needing to crush the cartridges before melting and yesterday we cut up a short length (70 mm) of 5mm wall x 40mm ID pipe (70mm) and made up a small press using a car jack. This doesn't seem to be working all that well - it seems like he'll need a heftier jack.

    A trial melting plan is to transfer some of the crushed cartridges to a 50 mm long piece of 25mm water pipe with a piece of steel welded to the bottom so it can stand up in the forge and just melt the brass inside the pipe. The question is - will the greater coefficient of thermal expansion of the brass (meaning the brass will shrink more when its cooled) allow for the solid bras slug to be removed say with a press?

    Apart from the obvious of careful inspection to make sure the cartridge is empty is there anything else he should be aware of. Is it worth the bother of cleaning the cartridges in something?

    His ultimate goal is to cast round nose brass heads for his long bow - these are around 11mm in diam x 19 mm long and have n short 8mm hole in the into which the arrow shaft is inserted - currently I turn these for him but I am over doing this.
    He'll almost certainly want to scale up from the charcoal forge to something a little larger whereby he can say cast 10 or 20 arrow heads at one time./

  2. #2
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    Quote Originally Posted by BobL View Post
    A trial melting plan is to transfer some of the crushed cartridges to a 50 mm long piece of 25mm water pipe with a piece of steel welded to the bottom so it can stand up in the forge and just melt the brass inside the pipe. The question is - will the greater coefficient of thermal expansion of the brass (meaning the brass will shrink more when its cooled) allow for the solid bras slug to be removed say with a press?
    Probably, but you will have to see. It would help if the inside of the pipe was smooth (no fin) and tapered slightly outwards.

    Quote Originally Posted by BobL View Post
    Apart from the obvious of careful inspection to make sure the cartridge is empty is there anything else he should be aware of. Is it worth the bother of cleaning the cartridges in something?
    Any dirt will become slag on the top. Apart from the dangers of working with molten metal at around 900 degrees C, remember that the zinc will fume off from the brass, so the composition will change as well as the obvious health issues to be considered.

    Michael

  3. #3
    BobL is online now Member: Blue and white apron brigade
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    Thanks MG. Well he's had a go and reported back that he's made a "few scraggy looking molten blobs". I don't think he can control the temperature too well (or at all really) and he admits he needs a better heaT source.

  4. #4
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    Keep in mind that cartridge brass has approx 30% zinc content and will be giving off toxic fumes, more so than other brass like round stock or plumbing fittings.

    Have never melted spent cartridges but I have heard they dross badly, you lose a bit of brass. With tricky metals it helps to get a small molten pool going then feed into that, rather than load up the crucible from the start. Good luck!

  5. #5
    BobL is online now Member: Blue and white apron brigade
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    Thanks Ratters.

    I'm going to steer said relative away from experimenting with the rifle cartridges and instead use some old brass plumbing parts.

  6. #6
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    When I was doing the Foundry course at Wollongong TAFE they wouldn’t put plumbing stuff in the pot. There were complete tap bodies in the 20 litre drum of scrap I had.
    They’d had explosions from water in taps.
    Be ok if you dismantle everything and preheat on the furnace lid.
    H.
    Jimcracks for the rich and/or wealthy. (aka GKB '88)

  7. #7
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    If yer chasing some cheap brass to melt down I’ve seen some cheap lots of large unused brass plumbing fittings and large door hinges, etc, going through the Pickles monthly military auctions.

    https://www.pickles.com.au/campaigns/ex-military/auctions/industrial/sale-type/Ex-Military/buy-method/Pickles%20Online/sort-by/custom-date-ascending/page/1


    Not items I’ve been bidding on so haven’t paid close attention though I think the items are navy related.

    Been a few lathes etc go through recently.




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