I have used mine several times you will not warp the sheet metal because of the water and it works good. they pump sand at a much lower pressure then the 2500 psi of the pump. I have a 2500psi honda motor one. the sand blaster end I bought at wal-mart for the rediculous amount of about $15.00 didn't ask why they where so cheap when others sell them for over $50.00. also bought the small tube that you use to clean traps and drains for a little money. not sure they still carry them this was about 6 years ago. Ed