OK then, serious (foil) hat on now: Caldera Clones.
I googled them and found a long and detailed thread on Outdoors Magic here[/url]. I emailed the guy who worked out a template to create them and he sent me the latest version. It uses PostScript language, which for PC’s you’ll need to download some (free) software to open it up. I use a Mac, which conveniently turned the .ps file into .pdf without me having to do anything special.
I fiddled around with a couple of paper versions first to try out the various parameters of the template:
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Caldera Clone – paper trial[/url] by ianbarrington[/url], on Flickr
Once I was happy with the a template, I sourced some 0.15mm alu foil from here, and then printed and cut out out my final template:
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Caldera clone ready to be cut out[/url] by ianbarrington[/url], on Flickr
After about half an hour I had this, though I still need to add the vent holes:
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Completed Caldera Clone[/url] by ianbarrington[/url], on Flickr
The final version I produced had a series of fissues on it that interlock, so I can split it down into two parts, roll it up and pop it in my pan, thus:
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Caldera Clone packed[/url] by ianbarrington[/url], on Flickr
It weighs 21g, which is a 5g lighter my the other one, but looks more stable and more effective at excluding drafts.
Overall it was all a bit of a faff, but I’m quite pleased with it. It cost me £7 instead of £35 for a proper Caldera one. However, I suspect that the Caldera ones would be a thicker grade foil, as you have to handle this stuff a little more carefully. Because of this, I think it will be susceptible to picking up small creases or folds through use, but we’ll see.
As ever, you learn a lot doing the first one, and there is only enough foil supplied to do one, even for a small pan such at the Tibetan 550.