Improving vacuum cleaner performance
I use a vacuum cleaner with a plastic nozzle on the concrete floor of my shed, and the abrasion had worn it flat. The flat nozzle would just stick to the floor, and the airflow would be blocked. I glued a washer to each side of the nozzle with some two-part epoxy (Araldite, pic 1), and now it works perfectly again because of the small gap (pic 2) between the nozzle and the floor. The metal washers should stand up to abrasion better than the plastic, and can be easily replaced.
A high return for a 10 minute job.