Here's the naughty shot:
A coil of 8mm tube, wound round a jar of about the right size (not the one in the photo - a stainless storage jar which I've just blown some holes in with the MIG welder when trying to do an improved heat exchanger
):
I've crimped the tubing with a couple of inches between crimps, following these tests.
Here I've started sewing the tube onto the plywood spacers from the Quad IC project:
and here I've added vertical supports made from extra 8mm tube with the ends flattened and bent over:
Here it's been mostly soldered together:
Finally here is the water test:
Chilling results were inconclusive because I had problems with hoses during the brew (post now online) - it actually took 39 minutes to get from 97 degrees to 23 degrees C, including forgetting to start recirculating the hot wort, and the hose coming off the tap about five times
The longer-term aim is for this chiller to be the inner coil of a twin-coil chiller plumbed permanently into the shiny boiler, when I get it together. I rather like the idea of just plugging the garden hoses onto the outside of the boiler
In case anyone was wondering about glamourous settings for shiny porn, here is the setup with the old Vivitar 283, with blue filter and telephoto Fresnel lens, clamped to the banister with a Gorillapod SLR, while I used the Metz 60CT1 for fill. I'm afraid I almost always use the on-camera flash for brewdays pics.
Ooo Techie!! 
... Fine piece of work.
