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 ..................
anyways... i don't trust paints that are going to go into a reef system... and i ended up going with 1" and 3/4" pvc for my overflows... i'll post up pics in the other forum... they're going to look horrible in my tank but f*ck it... i don't want to jepordize the aquatic fauna and floura for asthetics...