How feasable is stamping your own pots with lips* from thin alu? In the absence of much expensive equipment that is.. Eg if you wanted to make a hyperUL third inner pot for a trangia (ie an inner-inner pot ). * for the pot grabber to grip on.
Do you need to? I think most pot lifters grip the pot wall rather than the lip, but they have to be able to accommodate the lip to do so. Also, if you're aiming for 'hyperUL', you might look at the GSI Minimalist pot grabber, (<½oz).
I'd recommend pressure spinning it - only needs a hardwood original form to build the form of the sheet metal disc against in your lathe. That's the way lots of thinwall round things are made. /Odd
I had assumed the pot gripping was made more secure by the lip having lost dinner on the v1 duossals' less substantial lip cf plain alu 27 pots.
The pot from one of these does exactly what you want: Sportztrek Hard Anodised Trek Set - 5 Piece They are an Australian brand, but I assume a Chinese item available through other brands in other places. The pot is slightly narrower, but squarer in the corners compared to the smaller T27 pot. The height inserted works. The squarer profile means there is a small gap under the pot when used as the third in a T27. The contact is the bottom edge. Still, does what you need. Burner and gripper fit. I don't have UL to compare. The Sportztrek pot weighs 70g. It is hard anodised. My older T27 pots weigh just over 100g.
@TRA_A I think it likely that you'd need to anneal (soften) the alu sheet to make it ductile enough to form without cracking, as that metal work hardens quite rapidly - i.e., if you put it under any stress, by bending, twisting, hammering, etc, it gets harder and harder until any further stress will make it crack. Almost certainly, it won't be pure aluminium, but an alloy of aluminium with one or more of copper, magnesium, manganese, silicon, tin or zinc. The mix has a marked effect on the properties, and unless you know the composition and grade, the simplest way to check is to bend it into a fairly sharp radius and see what happens. If it bends without apparent cracking, but the surface on the outside of the bend looks rather white, it needs annealing. The white appearance is actually a myriad of tiny surface cracks; if you see them, the metal is too close to cracking for comfort - especially if it will have boiling water inside it! Be warned that some Aluminium alloys - such as those alloyed with copper and zinc - are so fussy that you need an industrial grade annealing oven, and maybe a timer which can control the rate of cooling to 50 degrees F per hour. And both are very prone to stress-cracking! Light alloys used to make pots and pans are commonly Aluminium Manganese alloys. These are very formable, and anneal fairly easily. Aluminium Magnesium and Aluminium Magnesium Silicon alloys are commonly found in sheet form, can be worked fairly easily, and are pretty easy to anneal. A home workshop way of annealing these alloys only needs a source of heat and a bar of soap. Smear thin lines of soap on the top surface, then heat the alloy as evenly as possible on the underside until the soap turns brown. Leave to cool down naturally - don't quench in water. Annealing temperatures range from 650 - 775 degrees F, depending on grade. This is getting pretty close to melting points, so take great care to heat evenly, avoiding the creation of hot-spots. Depending on the amount of bending / stretching, you may need to do it in stages, stopping short as soon as your feel the metal getting hard, and re-annealing before working it some more. HTH, Gunner
