You did not specify voltage and I presumed that you knew that these two models are only made in 110V as you had looked at them. Easy to find a converter which isnt expensive and what anyone buying a 110V would naturally use...
Take a look at 2k lacquer spray. Waterproof and hardwearing. Although primarily for cars I have used it on outdoor furniture and it has lasted for years
I thought of that but have since discovered that the motor is a sealed unit which is destroyed if opened up. Its probably the brushes burnt out and they are not replaceable on that unit anyhow as far as I understand