there are 2 different types of PVC cement...one cleaner/glue together and one primer and glue in seperate containers....i swear by the seperate components myself.....and yes it basically melts the plastic and alows the gluse to make a chemical bond between the 2 pieces of plastic........on pipe you would wipe the primer on then the glue.......put the pieces together and give them about 1/4 turn and hold for 30 seconds or so....this really gives all the surface area a chance to bond ...................but pvc to toilet ring might be a little tough ...i'd still use silicon just in case ..............

And I don't consider myself a plumber....lol more an excavator that installs septic systems as well as other things........lol ....i never mess with the toilets...unless it's my own ..................

Boss