hello, im trying to build an orb, using thick aluminum wire, that will break down into 2 halves, making it easy to store. my idea of the design will have the wires soldered to a washer on the top and bottom of the orb (ball), using a bolt of some sort, (stacking the washers) to hold the two halves together when it is being used. having trouble soldering the wire to the washers.. is aluminum not a good material to use? i was drawn to it because of how lightweight it is, along with being strong enough to support weight of other balls on top of it, ..and it reflects the light well.. please help. appreciate any suggestions.

my wife purchased a set of plastic cutting boards. They are great, BUT they slide around on the counter tops. She's old school and won't do anything to keep them in place (wet cloth, paper towel etc) so I'm wondering if there is something I can put on the back to keep them in place. The back has a texture of small dots, here shown up close. Not sure it would take a self stick rubber 'dot' or not. Looking for spray ideas which would also work in the dishwasher (though I'm not above washing them by hand if need be.