Couple of stir plate build questions

What type of epoxy do you guys use to glue the large washer to the fan? I tried hot glue and it doesnt stick worth a damn.

Do you also epoxy the magnet to the washer?

The fan I pulled from the old tower does not seem to have a lot of oomph. It spins just fine, but it doesnt take much to stop the spinning. A light touch and it stops. Is this normal?

I just used super glue with the washer. Then the magnet just sticks to the washer without glue. I stack two magnets. Also, my fan is pretty weak too, but it's still enough to spin the stir bar in 1500 mL.

Hmmmm...I used hot glue on mine and it's held for almost three years now. I know there are different types of glue sticks (heavy duty versus general purpose) so maybe try a different one.

Regarding the fan power, how many volts is your power supply? Could be that your fan is worn out if it came from an old tower. I only run 6 volts through mine because 12 was way too much power. It has quite a bit of power though...I wouldn't voluntarily try stopping it with my finger.