Casting brass or bronze

[AjohnwParticipant @ajohnw51620]

[AjohnwParticipant @ajohnw51620]

Does any body have any experience if this. Likely pouring temperatures and fluxes etc.

Zinc fever might concern me on brass and silicone bronze seems to be the best option with that one.

But info is scant. I was surprised to see brass being cast on youtube complete with white fumes.

John

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[DMBParticipant @dmb]

If you do, drink a pint of milk as an antidote to the zinc fumes.

Loss of zinc via the fumes is countered by adding extra zinc to the already molten mix but I dont know how much.

There are so many different grades of brass for various uses that I suspect the foundries have some sort of scientific means of checking the proportions of different metals in the alloy.

HTH.

Personally, I would do the patterns and pass on to some other mug to do the actual casting.

John

[Johnboy25Participant @johnboy25]

Hi… Take look at bronze casting on YouTube in particular there's a guy under the pseudonym of Doubleboost. He's made loads of useful video clips on all sorts of machining and engineering topics. Well worth a look.

John 

[AjohnwParticipant @ajohnw51620]

I've decided to give brass a miss. Bronze is of more interest anyway but some grades do have a fair amount of zinc in them.

Doubleboost's casting video's aren't much good. If interested people would get a lot more info from Myfordboy.

John

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[Johnboy25Participant @johnboy25]

Sorry I wasted my time mentioning it…

[Martin ConnellyParticipant @martinconnelly55370]

DMB, I tried to find evidence for the use of milk as something for welders to use as an antidote to welding fumes some years ago (for where I work) . I failed to find any research, do you know of any that exists, I came to the conclusion at the time that it may be an old wives tale but I would love to be sure one way or the other.

Martin

[Clive HartlandParticipant @clivehartland94829]

It is maybe the calcium in the milk that acts as a chellate? I remember the spray painters getting a pint of free milk a day but not the workers close by who were also getting affected by the vapors from the paint.

Clive

[Martin ConnellyParticipant @martinconnelly55370]

UK HSE state that drinking milk does nothing to prevent metal fume fever. Milk is sometimes suggested for ingested metal based poisons but I have not been able to find definitive research on the subject of milk for the prevention of metal fume fever.

Martin

[AjohnwParticipant @ajohnw51620]

Posted by Johnboy25 on 01/01/2016 22:48:29:

Sorry I wasted my time mentioning it…

No need. I just thought it was worth mentioning a better source of info. As a for instance you can just stick metal in some sort of furnace and heat it up but to what temperature? He does cover that for aluminium and brass and a cheap way of measuring but I would buy a dvm that can measure temperature rather than a controller, however the controller can be cheaper. Plenty of info on moulds too. It can all save people a lot of time figuring it out for themselves. He even admits his mistakes and mentions why at times. He's had several furnaces.

Forgot to add that Doubleboost does do some good video's as well of course. I reckon he is basically sound. I think he mentions using carbide inserts above centre – best look at manufacturers data for that. Some should ideally be used like that but it's a pretty small amount, probably because the cutting edge isn't actually sharp.

Personally I think zinc fever is best avoided and as copper alloys tend to be expensive anyway may as well use another one other than brass. it's probably safer in a propane furnace as there should be little oxygen about so the zinc may not oxidise but when it comes out it will and is likely to fume anyway. Myfordboy uses borax as a flux.

Zinc fever has also been called Monday Flu or something like that. It's possible to develop some resistance to it but it disappears over the weekend. Sounds to me like something that really needs extraction and plenty of it.

John

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Edited By Ajohnw on 02/01/2016 11:13:57

[Clive HartlandParticipant @clivehartland94829]

A bit more research comes up with a recommendation to take Vit. C. and then another says to take cold remedies as they have SpeudoEphidrene in them.

By far the best 'Cure' is to use an air fed mask which would eliminate any inhalation of the Zinc fumes.

Clive

[Bob StevensonParticipant @bobstevenson13909]

There is a man by the name of Knolle Shelley who is an excellent brass caster and gives a very interesting talk/demo. I know he has been to several model engineering clubs in the south of England including some more than once. A couple of years ago I went to his talk at Chingford Model Engineering Club by invitation of a member who is a friend (thanks again Gordon!)

 

Basically, he does not add any zinc and does not fear the fumes…..he controls temp very accurately using a thermocouple and pours at 1070 degrees…….failure to do so risks a 'shunt', a fault in the cast due to the metal cooling as it pours…….heats using propane………allows for the slight shrinkage when making the patterns…….uses Bentonite enriched sand……..makes lots of bits for the traction engine fraternity which come out f the sand needing little or no finishing………he had a beautiful name plaque about 18 inches long from a traction engine where the owners only had the one side and he used this as the pattern for the replacement one for the other side…….quality was superb although he demonstrated that shrinkage meant the new plaque was actually slightly smaller than the original.

Edited By Bob Stevenson on 26/01/2016 01:14:09

[jason udallParticipant @jasonudall57142]

Mmm..ignoring for a moment the hazards of zinc fumes…

What is the loss rate of zinc…
I mean what is the composition of the alloy if “cooked” for a while…would the notional alloy of copper/zinc reach an equilibrium when the “excess” zinc has evaporated ?..
Brass..horid stuff..usesless in boat fasteners. .you get de zincification..and are left with crumbly copper screws

[jason udallParticipant @jasonudall57142]

Btw. There exists kits for casting (brass) using a microware oven ..basically lost wax investment casting with special slip that creates the “crucible”

[Chris Evans 6Participant @chrisevans6]

Where are you based ? Lots of brass foundries around the Black Country area of the West Midlands. I used to pass two on the way to work but both recently closed.

[Ian S CParticipant @iansc]

How's this for high-tech. Ian S C

[Neil WyattModerator @neilwyatt]

Does a floppy hat and loin-cloth constitute adequate PPE?

Neil

[Ian S CParticipant @iansc]

Neil, yep.

Found these a while back when a thread on Sterioscopes came up, andI had a look through my box of photos from early last century.

Ian S C

[AjohnwParticipant @ajohnw51620]

Thanks Bob. The the info that seems to be hard to find is a suitable pouring temperature for brass.

The fumes are likely to be a problem for a simple electric furnace. It would probably need to be a true muffle to keep them away from the elements.

Maybe propane is the best bet what ever is being melted.

John

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