Aluminum is slow to dissipate heat. It has a much higher capacity to store heat, but slows it's transfer considerably compared to SS, and hilariously slow compared to copper.
Basically I'm only hooking up when i'm ready to serve and washing it aggressively before and after. As soon as i can scrape up the money I'll switch to a preformed Stainless coil, but this is cheap effective and safe if used intelligently.
Mostly though it was that a 25' x 1/4" ID copper coil...
I came up with a nifty idea about how to build a jockey box. It went something like "I already have one... it's just disguised as a mash tun. I'm rather handy so I schemed up a jockey box.
Shopping list for jockey box
1/4" x 25' copper coil
10 feet liquid keg line (in two 5' sections)...