I wouldn't plug a solenoid into a surge protector. I'm willing to bet that when the solenoid fires, it will send a nice spike through the surge protector. I don't think that little resistor and capacitor will do much to filter that out. A good surge protector will cost as much as the solenoid. I would plug the solenoid into GFCI outlet though. Just in case the solenoid decides to melt and short out.
