Hi I am just starting out. I decided after much looking around to buy a Fucina Furnace. https://fucina-forges.com/products/...elting-furnace-propane-forge-metal-melter-usa I had options to try to make my own but given I work full time and it seems like a lot of figuring out I thought this would be easier. I look forward to learning from everyone here and contributing where I can... I have some questions about crucibles and which are the most durable... which I need to know.
That furnace seems like reasonable value for money however it doesn't appear have any sort of coating on the kaowool, that's important for your health and the longevity of the furnace. The video in THIS THREAD will show you how to apply a Satanite coating
I wouldn't buy one of those furnaces.. Just another tin can with some kaowool and a 20dollar burner. When a company calls their furnace a forge, it tells me right off they don't know WTF they are doing. Besides, I spent less on my furnace that will last me easily a decade. One more time for the easily confused.
Actually, they call it a "Propane metal melting furnace propane forge metal smelter", which is least as wrong. Anyways, I'm definitely in the build your own camp but for someone that for some reason can't or doesn't want to, that one looks at least as good as any of the other similar type furnaces out there. It's got a nice regulator with a stainless steel burner, fairly thick wall construction, all it's missing is a durable hot face. It would probably cost close to $200 to build something similar which, in my books, makes $320 for a completed unit reasonable value for the money.
I dont quite see that being able to melt 10KG with a 7.9 Diameter bore the 10KG crucible belows OD is 7.5 you need a full inch of clearence with Propane https://pmcsupplies.com/procasttm-no-8-10-kg-clay-graphite-foundry-crucible.html As metioned, its not rigidized, and I doubt it has a Plith , may not have a drain, I would pass V/r HT1
You see the certifications on that page? OMG, the only one they left is ICU-812. Fuel efficient AND meets every requirement the world over. Too bad it's more deadly than smoking. Wonder if it can cure our covid19 issue
I never went past the 'Maybe Later' graphic on that site. You never know what awaits the unsuspecting sheep.
Can be used as a furnace, yes. Can be used as a forge, yes. Can be used to smelt metal, yes I suppose so. The only mainstream keywords the left out were gold and precious, but they're all valid. Anyways, welcome. Whatever crucible you decide on you have to consider it a consumable. You can buy a high dollar silicon carbide crucible that might last a novice his whole life or you can buy a much less expensive clay graphite crucible that might last a novice his whole life. A lot depends on how it's used, how it's handled, and how it's stored. All of my crucibles are clay graphite and my very first one which is about 8 years old has finally reached the end. It has at times not been used well, not been handled well, and not been stored well (but never dropped). But it doesn't ring anymore. The one linked above is a pretty good price from a reputable dealer. Decide as close as is possible what metal you want to melt and how much of it. Figure out which crucible to get, and then make your furnace decision. HT1's observation is spot on. You need to lift your crucible out with the proper tools without shredding your bore. Using pliers on the rim is stupid and indefensible. Your bore needs to give at least an inch around the crucible for combustion and lifting. You'll probably be buying more than one so I'd start on the smaller side. If you took an empty 5 gallon steel paint bucket, lined it with wool and coated with satanite, which you have to do anyway, cut the top 3 or 4 inches off the top of a second paint bucket with the lid still crimped on and lined and coated it, it would be 100% as effective as the fucina. A burner is $100 on Amazon, the wool is 50-$60 on Amazon. Get satanite at hightemptools.com. Pretend it's a kit from two different vendors with some assembly required. If you need a bigger furnace you can use a hot water tank or beer keg. Building an effective propane burner isn't hard either. Yes there would be some work involved, but once it's done it'll be done. Pete
Another vote for a clay graphite crucible, it should last a long time if treated with care. I try to take good care of mine but I do have one I've decided not to use again. It was given to me used by a blacksmith friend who only rarely does any casting, and who knows what horrors the thing had endured in his coal forge before I got it... It has a surface that looks like dry, cracked earth, and a bunch of sticky goo came out with the dross when I skimmed the last melt... Maybe that goop was just some old flux he had been using finally coming unstuck from the bottom or something and I could get a few more heats out of it, but there was a lot of it, and for all I know it was melted bits of crucible or something... Clay graphite crucibles aren't expensive enough that I'd rather take risks and be nervous pouring than just pay the man. I expect the ones that only I have used will last for years and years though, they are all still in great shape. Hey, what a coincidence, FedEx just dropped off my new ones! The homemade furnace in the thread Rocco linked above cost mrhomescientist $300 for the custom welded steel outer shell plus another $90 in materials such as ceramic fiber blanket and Satanite. That is why a lot of us advocate building your own using scrap metal; some do the welding themselves, but most simply use an old (ideally free) scrap propane tank, steel bucket, air tank, or whatever is handy to build the furnace in. It's fun and it's cheaper. But no worries, yours should work fine once you get those ceramic fibers get sealed up. Good luck! Jeff
I'd just get a silicon carbide crucible and be done with it. Best money you'll spend. They are near indestructible. There's even a guy on youtube that heats his up to >2000f then dunks it in cold water and it doesn't shatter, and he keeps using it. Too rich for my blood but I think it proves the point they are durable. And if there's one characteristic you want in a crucible its durability. Unless you don't like your feet. My 2 cents.
Only for non-ferrous work. A clay graphite crucible can be used for most any metal service and is considerably less expensive. Durability will vary. I get hundred of melts out of my clay graphites in aluminum duty. SiC is more thermally conductive and likely to produce modest improvements in melt time. Flux resistance can also be a consideration. Best, Kelly
