I'm quite new to steel trowls. Mine seems to get in a right old state. I rub it with a wd40 rag at end of day which seems to minimise rust but doesn't stop the build up of plaster over days. If I was to leave it in a bucket of water like I used to with stainless I'm guessing it would rust. Also if I give it a rub with sand paper am I ok to rub back to shiny metal? Thankyou in advance for any help