Built a Peltier Block with a Swiftech Apogee GT

[initialised]

I bought this:

It was covered in some green gunge, probably a combination of algae and copper sulphate.

I cleaned it up with a dip in some Cillit Bang.
This etches the surface the redeposits the copper
Then passivated the water contact surface using a blowtorch.

This forms red copper oxide and should act as a barrier to electrochemical corrosion by forming a thin surface layer without hampering thermal performance.
I put it all back together and lapped the base to 1200 grit, cut a 50 mm x 50 mm coldplate (only 2mm) and lapped this. I find a rubber glove stops it slipping.

Applied Arctic Silver Epoxy to the base of the block and did the same with some Ceramique mixed in on the cold side and clamped it using a spare acrylic top from and Alphacool block.

The Peltier is a Qc=226, Pmax=350