Metal working/Casting

[ScottishGasMan]

Watched a few videos a while back about homemade furnaces etc for melting down aluminium/brass and casting new things from it.

Working in heating trade I've generally access to quite a bit of scrap brass, any one do this sort of thing on here already?

 

[ladylola]

Funny you should mention it but we did just that this weekend on a re-enactment. Our group has a forge normally used for ironwork but this time we heated both brass and copper in a crucible. The first attempt at brass wasn't perfect as when the lid was removed yellowish smoke or vapours came out of the crucible. It did however melt and we successfully cast . The next time we tried copper , copper pipe to be exact , but added crushed coke to the mix. This helped a lot and the resulting melt was trouble free producing decent castings in sand. Copper melts at around 1083*C and of course the working temperature needs to be hotter probably around 1200*C .

 

[Dave54]

There was quite a good article in Practical Classics magazine many years back about metal casting. (A web search says it was May 1980) You may be able to get hold of a copy on eBay. IIRC they used a reversed vacuum cleaner to provide the forced air into a bed of coke to melt the brass. From what I remember (and I've always been meaning to have a go at it and never got around to it) they used "degassing tablets" in the melt. It helps stop oxidisation I think.

 

[ladylola]

Ah degassing agents , that'll be what adding the crushed coke or charcoal is doing , stopping the oxidisation when the air gets to the molten metal. Ours "burned" only when the lid was removed on the first attempt. A site to check out is Taranti's http://www.tiranti.co.uk/EdgeImpact...&Content=Casting+Casting+Tools+and+materials+
interesting but a tad pricy .

 

[Dave54]

AS you say, interesting. They look more aimed at art / jewellery and so on though. I haven't looked, but I'd assume the bits and pieces needed would be easy to get off t'internet these days.
Again IIRC. (I think I can remember getting that magazine. I'd cut my hand and was walking back from the hospital) they were sand casting in the mag. They made some castings from old car badges I think. Of course if they were using originals as patterns the new ones would be slightly undersize, but that wouldn't matter for some things.

 

[theprinceofdarkness]

I believe the big problem with home casting brass is that some of the zinc evaporates during the melt (the yellow smoke?).
Frank

 

[oilboffin]

look on Camden books a bloke called gingerly wrote a book on how to build a gas fired
small furnace from bits and pieces and it really work can melt glass in 2 mins

 

[Razor900]

Check out Grant Thompson King of Random on youtube

He has loads of vids including ones on how to avoid oxidation!