# Washing Cement No Buchner Funnel



## Profikiskery (Jun 14, 2016)

I haven't seen any posts on this so thought I would share.

One thing I do not have yet is a vacuum system with a Buchner Funnel. Needless to say, if you have a good amount of cement, gravity can take a while and many washes.

I have found if I decant, then add some filtered water to the cement, still in the beaker, and preliminarily wash it in there before pouring into a filtered funnel in a separate beaker saves me a ton of time. I pour that cement into a filtered funnel and wash it one more time to see the color, but have found I rarely have to wash it again.

It has saved me a few hours and hope it will you guys too.

Craig


----------



## 4metals (Jun 14, 2016)

Another trick to speed up the filtration in a standard tapered funnel is to use screening, the same type used under the paper in a buchner funnel, fiberglass window screening. 

If you cut a circle of the fiberglass screening the same diameter as your filter paper and fold it in half and then into a quarter size (shaped like a pizza slice) then open it up in the funnel just like a filter paper. Then add your filter paper by folding it the same way so you will have a screen in the funnel and a filter paper over the screen.

This will keep the paper from sticking tightly to the funnel wall and preventing flow through the paper because the filter papers surface area will not be blinded by it's adhering to the plastic or glass of the funnel. 

Your trick of lining the filter with rinsed cemented silver is still a good one to prevent clogging the pores of the paper but combined with this technique the overall flow will be better.


----------



## Profikiskery (Jun 14, 2016)

Makes total sense....since I have no Buchner, I am not familiar with the screen, but a great suggestion. I lose a lot of filtration time just for that reason...filter stuck up against the sides of my funnel. 

On it!!


----------

