Just another backyard tinkerer. A long time ago I took, and eventually started teaching metalworking and welding at the community college in northern Arizona (which was actually held at night at one of the local high schools). Besides mills, lathes, spot welders, plasma cutters, brakes, and all that other stuff, we had a gas forge and foundry. One of the nicest features was the flooring was a grill over a raised pit, so any spilt metal wasn't an issue. I also managed to find a long throw optical pyrometer with a separate display, and mount it up on the fume hood over the foundry pointing right down the hole in the lid, and you could watch the melt temperature from anywhere in the room. Forms were steel flasks and petrobond sand. Melted a lot of cans (so many cans), and a lot of brass scrapped from a local hydraulics company. After doing the shop patterns, it was interesting to see what the students would bring in to use as a pattern. But I put that all behind me and moved to NY ten years ago. Then I moved to Space Coast in Florida (go rockets). And then I moved to Waterloo. It's a long tragic story, best told with a strong drink. Anyways, watching too much utube, and Paul's Garage gets this little desktop electric hotpot, and I'm thinking to myself, I could do that. Ordered it up. Decided the graphite crucibles were a liability, at least for aluminum, so made my own steel ones, just for scrapping (1/8" wall, 1/4" base, TIG welded with a spout); and have melted down a little over fifty pounds of aluminum foil and food trays. Inspired by Kelly's lost foam work, I made up some laser cut paper forms, coated them in wallboard mud, and did some castings that way. Needs a little work, I had forgotten everything I ever knew about shrinkage, and I'm thinking of using some piranha solution for better removing the paper next time. Now I'm looking to upscale, because that little oven is just slow. Wired a new 40A 240V circuit in the garage, and doing some calculations. Will be making a trip further north to the nearest big city to hit up a refractory store for bricks, fiberboard, and castable material.
Welcome woolstar. Looking forward to a build thread on your furnace and casting projects. Nothing wrong with scrap casting stock but think you will find casting with stock that were previously castings will produce better results than wrought alloys. Best, Kelly
Here's an action shot of last summer's casting setup. Don't worry I have heavier gloves for working with the metal, those were just for forming the scraps. Sometimes will also run a hot-plate to pre-heat the metal and make sure there's no moisture.
Also here's some 4043 being sacrificed in my scrapping steel crucible (mk II). The first version of the crucible had a solid brim, and that wicked too much heat away. Yes I know wrought aluminum is not as good for casting, but it was free and it melted down nicely.
Since the weather was already miserable, and the kids had the day off, I decided to drive further north up to Minneapolis, to grab some supplies from Smith-Sharpe Fire Brick Supply. Great people, picked up a ton of brick, fiber board, mortar, castable refactory and some Minro z-wash. Always fun to go in person and check out the operation. Have some wire on order from Euclids, so when this all comes together, I'm ready to make a serious mess. Luckily I bought enough extra for a second and third attempt.
Some of my loot from the trip, These have been calling to me, but with temperatures below zero, they'll just have to wait a bit longer.