I want to pour a 100kg bronze bell and am looking into what methods I can use to do this as a backyarder! {1} Buy a cubicle large enough and build a brick kiln for it and use my tractors FEL to handle the crucible. This is the method I am leaning towards at this point {2} I could build two extra small furnaces and run three smaller ladles eg A40s. But I guess this has some logistical problems pouring from 3 separate ladles but is perhaps possible. {3} Build some type of fixed melting furnace that is tapable, which I at this point have no clue to there workings or should I say construction. Fuel to be used will defiantly be used oil! Any tips, advice, ideas, would be appreciated!
Just for completeness, I'll add one more, {4} a direct melting tilting furnace which can pour directly into a mold, maybe something along the lines of Master Yoda's design
Prob need a bigger capacity than 100kg to pour that. You need space for sprues and risers and whatnot. Maybe closer to 150 to 200 kg for a 100 kg bell which is about $2000 of metal at the cheapest price I've seen picking it up from the place in person.
Vincent, Are you going to do this once or make a habit of it? Have you given any thought to the mold size, mold material, and managing it? What's the OD and height of the bell? How adept are you at manipulating you tractor's arm? A gantry that tips and pours the crucible like a ladle may be more maneuverable. Agree with Zap on melt required vs casting weight. .....and I hate to say, but if at first you don't succeed, can you cut up and remelt a 100kg bell? Best, Kelly
I will probably only cast 3 bells that I could not handle with my current set up. the three bells will range from around 90kg down to about 40kg not including sprue or crowns. I was thinking an A130 or 150 would suffice They will be loam moulds, the biggest bell is around 450mm including the crown and 460 mm diameter Yeah bell metal is costly, it works out about $25 au per kg blending it myself, cost is not really the issue, the logistics of handling the metal is the issue in an economical way considering limited times it will be preformed. I have even considered adobe bricks to make the furnace, use three times and then use it for landfill.
It might be useful to do some research as to how bells were cast in colonial times. A quick search yielded the following: "Archaeological excavations of churchyards in Britain have revealed furnaces, which suggests that bells were often cast on site in pits dug in the building grounds.[7] Great Tom of Lincoln Cathedral was cast in the Minster yard in 1610, and the great bell of Canterbury in the Cathedral yard in 1762.[7] When the casting was complete, a tower was built over the casting pit, and the bell raised directly up into the tower.[8] In some instances, such as in Kirkby Malzeard and Haddenham the bells were actually cast in the church.[7]" It sounds like somehow a pit is made to perform as a furnace/crucible. For one-off or very few castings, such a method may be applicable. Surely there msut be some information providing more details. On a much smaller scale I recall seeing re-enactments videos of traditional methods used in Africa to melt iron and make agricultural implements where a small pit was dug, fuel and iron bits poured in and 10 to 15 people sat around the pit blowing air through reeds to melt the iron and form the implement. This is probably analogous to the bell casting methods enlarged to a much greater scale. The advantage being that being that the biggest investment is sweat and a small area of earth. Sounds like a challenging project and one worthy of chronicling. As an aside, if anyone knows more about the old-timey bell casting methods alluded to above, please let me know. I'm interested just for the sake of knowing. Denis
I don't wish to change how I make my moulds because the method I use making my moulds from loam has served me well so far! I also have ample supply of used oil so that is my preferred heat source. Above I mentioned using adobe bricks for a temporary furnace has anyone heard of this being done?
I'm not aware of adobe brick being used in that exactly fashion but I've seen videos of mud brick being used in single use cupola or bloomery furnaces so it seems at least plausible. I'm going to suggest a smaller experimental furnace maybe with an ursutz type oil burner, if that works, scale it up.
I saw a video of them casting a bell in the ground....right under a one shot furnace made from clay. They knocked a hole in the bottom of it and drained the metal into the mold under the furnace. I dont have time to search it but will later.
Having remembered seeing bell casting videos from medieval and (US) colonial times, I was on the same track as MS and Billy, thus my questions. If you needed to make one, those are good examples to follow. If you wanted to equip yourself to repeat the task, then maybe not. It's the classic trade of invested time for invested capital.....but there will be learning on either path. Best, Kelly
Today I just grabbed the bull by the horns, I Have ordered a Salamander A120. I will build a new brick furnace to suit the A120, I will build a swing jib crane and a new crucible lift and tip pourer, i will update here as I proceed! I will be able to use two furnaces to give me a capacity of around 140kg so I will be able to up my bell size
Gee that happened quicker than I anticipated went outside this morning and there it was sitting in the middle of the yard this is a mother of a size for what I am used to!
I know I posted this earlier, but this video has some good detail on incorporating a crucible properly into a tilting furnace so that it doesn't break:
I have been thinking a lot this morning, can I melt that much metal, how the hell will handling it on and on it goes. My whole life I have bitten off more than I can chew but I just chew like crazy!
You can get a peek at some nice heavy crucible handling equipment in the first 4 minutes or so here: Maybe that will give you some good ideas. The crane operated tongs and shank are in my care now and I've been meaning to dig them out of my shed and into the light to get some good pictures anyhow. Now that a lot of the snow is gone, I'll see if I can get to that this weekend and post some pictures. Jeff
I have a couple tilt-furnaces and one thing to keep in mind is that the pour spot varies by about a foot. I made a sort of refractory trough that exits through a funnel hole, so that the pour exits a fixed location. I think perhaps the best way is to build a ladle supported by a gantry or rail overhead. That's what I plan to add to my foundry next. Probably cost me $300-$500 and will have electric lift and will be 3-axes. A 2-axis system could be done with a single beam and could use a hand ratchet, come-along or hydraulic lift. Anyhow the idea of course is you pour into the ladle and the ladle is lifted and held at the height you set for you and roll it along a rail or gantry to where you want it. Then you have full pour control without having to lift it yourself.
I'm thinking something like this for myself - might make the beam cantilevered and on a pivot though. Probably do not need such a long beam of course - just long enough to go from your furnace to your mold. Then instead of a generator imagine a ladle. Or of course could build an crucible grabber to enable lifting the crucible out directly. Image from Champion hoist: https://amzn.to/3cbPcLx
