New member from SE Wisconsin

Welcome Redwolf. I get my crucibles from Legend https://www.lmine.com/index.php?main_page=index&cPath=1_2_142.
I've melted a lot of aluminum in them, some bronze, and will be trying cast iron pretty shortly. I've had no performance problems yet.
Overbuilding your furnace ain't a bad idea. From your O.P. I'd guess you haven't really decided on your fuel yet. I mostly run waste oil which requires a bit more combustion space than propane. I'm set up to run all 3 though (charcoal, oil, and gas). The fact that WO is free means that even if I'm using a small crucible in a larger bore furnace the inefficiency doesn't really cost me anything. Most folks recommend that you have your crucible in-hand before you start your furnace build, but I use a #7, #10, and #18 in my 10" bore furnace. If you want the capacity for a certain size it's a good idea to get the crucible first so you don't cut yourself short on bore size and so you can make your lifting/pouring tools to fit your crucible properly as well as fit into the furnace. There's only one way to get a hot crucible out of the furnace and that lifting tool has to be right. Pliers are not an adequate substitute!
Trannys are great casting metal. From my own experience with them do yourself a favor and clean that sucker pretty good overall before you start breaking it up so you're not dealing with the grime every time you use the stuff. You can get it to crucible sized chunks pretty easily with a sledge. As for the cans and 80/20, it'll melt and you can use it, but keep it separate from your cast Al.
There's a great bunch of folks here. You'll fit right in!

Pete

 

Thank you all for being so helpful with information and feedback. I may not post alot but I'm here and reading in the background. I may not get a lot done this year but I'm enjoying the education here..

 

Come on Petee... Anyone that's watched youtube knows it's perfectly safe to use water pump pliers to pick up a #10 full of melted beer cans.

 

As petee says the wrought alloy is a very different beast to a casting alloy. Night and day in respect to fluidity and shrinkage. It will cast but the silicon alloy will be vastly better and more rewarding when setting out.

Jason, I thought it was BBQ tongs?

 

Are you saying I might do better if I quit using extruded junk?