I have not had time to sort out my photos yet, hope to get to it the end of next week but here is the finished first bell, I made my own bell metal, 79% copper 21% tin, final weight is 13.5 kgs base width 260mm
Thanks, but probably more arse than class! (Aussie slang i think) The pour went really well right up till i assume the crown started to fill, and it started spitting and farting metal everywhere but I just kept pouring even though it was overflowing! any suggestions why this would happen, was it because I was pouring too fast or some other reason, to give some idea this is the vents and sprue setup
The main sprue probably should have entered the bottom of the bells rim so the trapped air could be pushed up and out without burping out the melt. As you have it gated now it probably filled the top surface of the bell trapping air in the lower section.
Gee I am ahead of time, I have thrown some pics of the process I went through, I am actually making two bells at the same time so some pictures are of the second bell which I hope to cast tomorrow. https://stonevahestate.tripod.com/bells/
Bells seem to be traditionally molded using this method so I doubt that is the problem, I am really starting to think as the bell fills the metal flow needs to slow, I am a few hours away from my second bell so I might get a better idea.
Yeah...the pour must be much slower or you will do just as David suggested. The vents do not let air out if they have metal blocking them. I cast mine from the top with no vent and the bottom without a vent. Failed twice with vents. Top is easier but bottom seems to be superior quality cosmetically and..has a better ring to it...just my opinion.
Finished mounting the bell today, it has consumed much more time than expected but I think it was worth it. I sand cast all fittings, the bottom post collar weighed heaps it just about emptied my brass scrape box