Hello Everyone, I'm planning on building my first foundry using a decomissioned 20lb propane tank, the standard kind you would see under a gas grill. I've seen a million tutorials of people building this type of foundry but I can only find one video of one designed to handle cast iron. I would like to start with softer metals and slowly work my way up to being able to cast mangalloy. Here are the parts I'm considering using: Ceramic Insulation: https://www.amazon.com/dp/B07C4V9LZ...olid=3GBH2PVN7XOF7&psc=1&ref_=lv_ov_lig_dp_it Choice of plaster: https://www.amazon.com/ITC-100HT-Ce...7SFP9RCF2B4S&refRID=8J1HB6WP7SFP9RCF2B4S&th=1 The plaster apparently has a max temp rating of 4500F. Crucible: https://www.amazon.com/dp/B07MNM388...colid=3GBH2PVN7XOF7&ref_=lv_ov_lig_dp_it&th=1 A foundry similar to what I'm looking to build: The only homemade iron foundry I can find with a parts list: My biggest question would be, does the ceramic insulation have to be rated to 2800F , 1540C or is it okay at 2600F? Thanks in advance, Raymond Bryant - Mechanical and Aerospace Engineer
Welcome Raymond, I have a propane tank furnace, 2" wool, Satanite coating. It accommodates an A6. With 1" wool, an A10 would be a better fit. If you're talking iron, see Melterskelter's thread on Blu-Ram. That's a CC crucible, get a Salamader Super, it's the most important piece in the foundry.
Here is one of my build threads. Works pretty well. Fairly heavy design. Used a scrap 30 gallon hot water tank. The ones that are heated with gas since they have an inner 3 inch diameter steel tube to funnel hot burning gasses past the water (free burner tube metal). http://forums.thehomefoundry.org/index.php?threads/furnace-wax-burnout-3-0-zapins.317/
Welcome Raymond! I'm a mechanical engineer too. You have come to the right place. A lot of resources here by people who are successful. The videos you posted looked like experimenters. I highly recommend Satanite. It is cheap and until it is fired you can let it dry out in a can and reconstitute it by adding water. Works great. I agree buy a super salamander. Don't forget to build the tools to manage the crucible. Where do you live? You can do a lot better on ceramic fiber by finding a local supplier. You'll be glad you did. Most folks build two, three, or four furnaces. It's a furnace, not a foundry. The foundry is where the furnace is used. Build cheap to start then build new if you need to when you get ready for cast iron. Time at temperature is what deteriorates insulation. 2,800F will last longer than 2,600F. With Satanite of HT-100 the wool will last longer. But it will still deteriorate eventually. Build it so you can replace it. My first furnace was a loose stack of 2,600F firebrick. Quick, no dryout, excellent insulation, and you can alter it at will. No exterior structure. Mizzou is your best bet for concrete. It is readily available. Inside of the lid (called the arch) the bolts the guy used will not last long. Holding refractory overhead is one of the difficult problems in building a good furnace. Refractory concrete holds itself but is heavy and does not insulate well. Ceramic fiber is excellent insulation but is friable and does not stand mechanical abuse after it has been fired. Stay off YouTube and read here, you'll get less misinformation. Some of us have YouTube videos. We're not experts but we are successful.
Welcome Raymond. The 3 men above have got you covered! I'm looking forward to seeing your build. You can find Salamander Super at legend mining: Lmine.com Pete
Mine is made from 2 20# propane cans (actual use is about 1.5 cans, wanted it a little taller than a single can would allow), inswool, and a satanite coating. I can fit an A12 in, but tend to use an A8 as it fits better and most of my projects are small parts. Can't comment on fuel as I'm using charcoal; I keep saying I'm going to move to something else, but until I run out of charcoal there's little impetus.
Okay, I'm gonna go with the wool I found on Amazon since I'm in too rural of an area to find a local supplier. Unfortunately, the 3000F wool I found only comes in bulk packages at a price of 2700$ per roll. I'll order the Satanite Mortar and I'll update you guys on the construction in this thread.
I don't recall where I bought my inswool, may have been the same place I got the satanite, I just can't remember anymore. But, for price checking here's HighTempTools where I know I bought the satanite from: http://www.hightemptools.com/inswool.html Seems to me for inswool and other large items, it's usually cheaper to buy more than you need as volume discounts often offset shipping costs, assuming one finds a use for the extra that is.
Thanks for sharing the link, I already ordered the material for this furnase but its very likely I'll have to build another one.
I'm 50 miles from Tulsa, so I'm lucky there are refractory suppliers there due to the refining industry. Other industries which result in refractory suppliers are steel making, glass making, brick making, mining, and heat treating for equipment manufacturing. They really are all over.
Lancaster found supply in Lancaster PA sells 3000f ceramic fiber blanket. They sell by the foot and ship. Its pretty inexpensive. I think I bought about 12x4 feet for around $100? They also sell 3000f cashable refractory which makes a great inner layer/face to contain flames. They also sell the cheapest everdur silicon bronze you can buy.
When you use wool, it is easier. Use chicken gauze as a 'reinforcement', wrap it over the wool and then coat it with Satanite (or Fermit). The gauze wires should be well buried (a few mm) under the mortar. Old wool pieces / leftover can be used as well to patch smaller holes. Note: always wear a face mask when working with wool, the ceramic fibers are bad for your lungs ! Finishing can be done with a wet brush or mixing the mortar with just too much water and painting it onto the surface, like wall paint. This will hold very well and after a few heats, the worst cracks can be painted over with the same mortar porridge.
