I have had numerous requests to make a tutorial for using a hand held palm sander to wet felt. This is the way that I do it. There are many ways to felt and I'm sure there are many ways to use a sander while felting. I will give some other options as I go along. You should try following the tutorial and see how you like using the sander. If you don't have the specific type of plastic or equipment that I use, don't let that stop you. Use what you have and give it a go. This is the equipment that I use. I will talk about each piece of equipment as it comes into use in the tutorial.
water, just lift your towel and place down carefully each time you move it. If the upper layer starts pulling up then stop.
Next you need to get some white vinegar. Do you think this is a big enough bottle? I use it for my dyeing as well.
If you try using your sander, let me know how it goes. I'd love to hear how you did and see your felt. You can use a sander for almost any type of wet felting. I have used it with nuno felting, using a resist, thicker felt etc. When you nuno felt with a sander, sand first from the silk side as opposed to the wool side. That helps the wool to migrate through the silk instead of felting to itself. Once the wool starts to migrate through, then you can turn over and sand the wool side. Any questions, please feel free to leave a comment and I'll answer your question.