just ask for a copy of the bylaws. don't tell them what you want it for though.
a body corporate can have all sorts of things in their bylaws - environmental, noise, smell, etc.
a recent complex I am familiar, without notice, prohibited washing of cars in one's garage or common areas, on the basis all roof and run off water was collected for use in the pool. this obliged residents to do it elsewhere at cost.
another complex I am aware of specifically prevented persistent operation of electronic tools and construction work. this came after one bloke tinkered on his Harley week after week, periodically giving it full throttle...and another resident decided to make a business manufacturing aluminium framed massage tables in his garage. He used angle grinders throughout the day 6 days a week. I know of another tenant who was asked to stop playing his electric guitar for hours a day.
when you live in close proximity, such as a townhouse or apartment complex, there are certain freedoms you have to surrender....otherwise it is rats trapped in a cacophony of noise.
I would have said no problems to your original post but sanding and spraying are a bit different.
Is it your garage (or are you renting). I wouldn't want overspray in my garage.
Also there is dust and fumes to consider.
Is there a unit above your garage? If so this could be an issue.
I go by the rules of- if it doesn't affect anyone else in any way there is no harm. If it does affect others think again.