Home-made fridge

[ChrisKlinger]

I'm setting up a coffee shop, and built an insulated corner into my bar, which I intend to use to display cold desserts. I scavenged a mini-fridge for everything but the evaporator, and tucked the compressor and condensor under the unit.

I'm using an evaporator from an old window-shaker, with a cap tube ( I forgot the length; if needed, I'll measure again).

I placed a muffin fan near the evap, routed to draw air through the evap.

Coldest temp I'm able to achieve is about 12C in the box. I've removed/compressed most of the fins on the evaporator to keep ice from blocking the unit, but if I run the fan, no dice, no ice, and 12C min. No fan, the evap ices, but i don't get the cold down from the evap to the rest of the box (evap is mounted to the ceiling of the unit).

I have some experience working on AC (as a helper when I was about 20, that being only a _few_ decades ago , but cold systems are completely new to me. What kind of low side pressure should I be looking for (R12)? Is my fan maybe too strong? Box not well enough insulated? Too large? (Maybe 20% more cubic space than the fridge the components came from).

Also, if I run a condensate drain to a pan, and place my (steel) condenser coil partially submerged, would I rust out in no time? increase eficiency? Be wasting my time?

Attached is a pic of the bar; the fridge is the part with the window (and a piece of wood holding up the condensate catch tray).

Any and all pointers appreciated.