Hi,
I sincerely hope you will find time because being in the US means you may be the first to experience 'difficult times'.
To make things easier for you I made 2 drawings and generated a couple of other ideas.
To make a simple water heater using solar power is shown above. You don't have to create parabolic structures.
But with a parabolic structure you will be able to concentrate much more heat. This will do to
pre-heat it a great deal ....
It's a rectangular mirror working as reflector. The tube should be half the size of opening side where the sun comes in.
As you can see it will perfectly be heated all around using all sunlight coming in.
You can easily and quickly build a 'grid' of this side by side either heating the tubes in parallel (making more water warm) or
connect them at the end making them work serial and thus generate less water but hotter ....
If you want to create a parabolic structure you can do it as shown above. It's a result of half the distance between
a dot and a straight line. I think the resulting focal point is twice the distance following the line square to the black line.
But that you will easily find by moving the tube up and down the line. The focal point will illuminate brightly.
I have built such a thing before. It was less than a square meter. Using weak sunlight on a late afternoon during fall
(in the Netherlands) it even boiled the water in less than 2 minutes !
I created it by jigsawing the parabolic shape in 2 pieces of plywood. I had a lot of mirror tiles. If you cut long but thin
pieces you can glue them in the parabolic structures. If you make the pieces too wide the parabolic structure maybe
too curvy to glue them in ...
Another way to set it up quickly is using tinfoil ....
I didn't do that before but I guess that if you take a piece of bendable carton and glue (don't make it bubble) tinfoil on it
may be working as well.
Mirrors will reflect more energy. However bending carton will give a more perfect parabolic shape than a series
of straight pieces of mirror.
I used a copper tube which I spray painted black. There is special heat resistant paint available ...
And finally I have another idea. I guess it will work but I didn't try it myself.
Once you have fresh water you might want it to be available somewhere high up in a tank in order
to have some water pressure. Consider this: you are already creating steam probably which will ascend by itself.
So if you delay the cooling process by keeping the steam hot all the way up it will keep you from carrying the resulting
water physically by yourself ....
Ok, this part is some of my experience with fresh ideas added. If I get new ideas I will post them here again.
Maybe it's an idea to post back results since the production of things may generate new tips as well.
Good luck you all