Finished the new version of the boiler unit for the tracker.

The mylar's a bit bumpier than I'd like, it's currently stuck with double sided tape but I'll try to source some spray on adhesive. You get the idea tho.

It actually holds together really well, the form is surprisingly solid for just four bits of card.

The boiler:

Just a bit of copper pipe squashed flat, painted black and sheathed in clear plastic. I've used metal epoxy to seal the ends as it's about the only stuff that will resist heat and ethanol.

Now I'm just waiting for some sun to test it. It should give about twice the concentration of the prototype, and that got eths boiling in under 20 minutes from cold.

More updates as things are finished.