I make QWET then filter cold material with my Buchner and vacuum. This it the first time using a larger pump then the crappy little one that came with my setup and I ran into an issue of fluid getting into the pump. While I was running it on my second batch I noticed the oil in the vacuum pump sight glass was a cream color. I then shut the pump off and disconnected the hose from the Buchner and the hose was full of oil from the vacuum, I'm guessing it was that oil it was thick when I blew it out of the hose and a few drops got into my liquids in the flask and if separated and floated at the top. Always, I been reading I need something in-between but what? I read about vacuum traps and Cold traps and to me they are the same thing.... What do I need?