Hi again, all
Somewhere further down these threads I showed my failed first attempt at bronze. Well, I melted all that cr*p again and managed to scrape the dross off (I used glass, which formed an extremely sticky lid into which all sorts stuck). I've also come by a huge quantity of spoiled hydraulic oil which seems to burn nice and hot, and is much cleaner than the nasty black motor oil I was using previously. The result was a 3" long bronze ingot in a baked bean tin which seems nice and solid below the top 1/8" which is perhaps oxidised.
Flushed with success I then tried copper; failing entirely on the first attempt, I then found a stack of ceramic wool insulation blanket. With this on the furnace I tried again, and managed to pour nice runny copper, again into a bean tin.
This time, on turning off the bean tin 'skin' (which had fused on, rather) I find the whole thing full of voids / gas bubbles from very small up to perhaps 3-4mm diameter.
I wonder if anyone can suggest ideas for what I might have done wrong? (Anyone in NW UK fancying a trip to Manchester might like to see my setup, give me advice, and perhaps leave with a length of ceramic wool furnace insulation!)
cheers
Mark
Somewhere further down these threads I showed my failed first attempt at bronze. Well, I melted all that cr*p again and managed to scrape the dross off (I used glass, which formed an extremely sticky lid into which all sorts stuck). I've also come by a huge quantity of spoiled hydraulic oil which seems to burn nice and hot, and is much cleaner than the nasty black motor oil I was using previously. The result was a 3" long bronze ingot in a baked bean tin which seems nice and solid below the top 1/8" which is perhaps oxidised.
Flushed with success I then tried copper; failing entirely on the first attempt, I then found a stack of ceramic wool insulation blanket. With this on the furnace I tried again, and managed to pour nice runny copper, again into a bean tin.
This time, on turning off the bean tin 'skin' (which had fused on, rather) I find the whole thing full of voids / gas bubbles from very small up to perhaps 3-4mm diameter.
I wonder if anyone can suggest ideas for what I might have done wrong? (Anyone in NW UK fancying a trip to Manchester might like to see my setup, give me advice, and perhaps leave with a length of ceramic wool furnace insulation!)
cheers
Mark
