I made a supersucker using my 6 horsepower shop vac. It supersucked. Not in a nice way. The plastic buckets tended to buckle and collapse, which also caused the lid to bend, warp and split. The contorted bucket tended to splash the waste oil back up towards the vacuum nozzle, resulting in a bunch of the oil being sucked into the shop vac. I went through three buckets in the process of changing my oil, as well as making a complete mess.
So, any advice on how to keep the buckets from collapsing? I am thinking about putting one bucket inside the other for added structural strength. A source for more durable buckets would also be welcomed. Lee
