If you are a fiber art novice just learning how to wet felt, using an electric handheld sander might seem intimidating.
Why do I have my students use a sander for wet felting, even if they have never felted before? Felting by hand is fine if you are doing a tiny project, but for large projects you will not be pleased if you try to tackle it with just your bare hands.
I felt every single day and I love my sander, it saves my back and speeds up the process immensely. Sanders are a must for most professional felters and even casual ones too. If you are very sensitive to loud noise like me just use cordless headphones to drown out the sander with music, or use ear plugs.
When choosing a sander I've had the most luck with the older models of finishing sanders by Black and Decker. The older models don't have holes on the faceplate that are meant to suck up saw-dust and when used for felting suck up water into the sander. My Model is the 7558 Finishing Sander by Black and Decker. Here are some other older models:
The sander must have a foam bottom face plate and not a velcor one. No orbital sanders, your sander can't have rotating or spinning parts that will touch the wool. Please remember that you do NOT need to use any sandpaper and leave the dust collecting bag unattached if there is one.
The first thing every one worries about is the mixing of water and electricity. I have honestly never even once had a problem, but if you are worried about getting your sander wet follow these simple safety rules.
Always use common sense when working with your sander. Less is more when it comes to water amounts when felting with a sander. Keep towels nearby to mop up excess water on the floor and your work area.
Plug your sander into a grounded plug when you are using it. Up to code houses have these. Faulty wiring is dangerous no matter what, avoid sanding in a location with bad or older wiring.