When I ship my ewaste I use FedEx ground and so need to keep my boxes below 70lbs. I used to rely on dumpster diving for boxes, and I still do it from time to time, but I also realized that sometimes it's easier to buy a bunch of standard ones, and they are not that expensive. For instance, when I ship a bunch of scrap laptops, I use these from HD. They also have heavy duty ones but I managed with regular ones (and maybe some extra packing tape).



Use mediums/larges for other types of scrap