To my knowledge there is no such material called aeronium. It’s a fancy word made up to call an existing very light and very strong grade of aluminum extrusion. My guess would be a 7000 grade which is loaded with magnesium. Posh mountain bikes are often made with it and if welded properly (subject to sound design of course) will last a lifetime, it’s also used in some aerospace applications which these companies love to promote because it sounds so cool………. My chair is made out of rocket ship and jumbo jet metal
Well that might be the case but it wasn’t built by bloody NASA.
Problem is it’s very difficult to weld especially the thinner gages and this is where the lifespan comes in.
I know from personal experience what a lot of aluminum grades are like to weld up and I know the skill involved. I’ve repaired dozens of mountain bike frames in the past (wouldn’t waste my time on a fishing chair)
For that very reason I’d sooner have a more commonly used, more weldable aluminum extrusion grade used for my chair like the older models because there is a far better chance it’s been done to a better standard.
In short the weight limit of your chair I wouldn’t have a clue! But the heavier you are the quicker you’ll suffer what I believe to be pretty inevitable.
The frame should suffer “creep” before the welds let go but sadly I doubt that will be the case.