I just bought a sintered-glass style Büchner funnel for some vacuum filtration tasks. There's two issues I'm having with it:
- Filter material, especially activated charcoal, ends up stuck in the glass disc. I did a little bit of research trying to find out how to clean it out and the only thing I found (for the carbon, at least), was piranha solution, but I have neither the equipment nor the experience to use it safely so I'm SOL on cleaning. Fortunately the presence of carbon isn't a huge deal for my uses, though.
- For paper filtering; the sintered disc goes all the way to the edge of the funnel, so unless I've got filter paper exactly the size of the funnel (which I don't), I'm worried that the 0.5-1.0mm gap I usually end up with around the edge of the paper gives fluid a path to bypass the paper. If I err on the side of larger paper it's still a poor fit with large channels around the edge.
It seems to me that the perforated-disc style of Büchner funnel would solve both of these problems; since the funnel itself can't trap filter material and also the holes don't go all the way to the edge of the disc:
(Incidentally, the pictured funnel on the left is exactly the one I own.)
My question is, given the two apparent disadvantages I've observed with the sintered-glass style funnel, what are the pros and cons of each type? More specifically, what could I do with a sintered-glass funnel that I couldn't do (as easily) with a perforated-disc funnel?
The context here is "kitchen chemistry"; I'm not a chemist I just do a few DIY projects here and there and all my knowledge comes from YouTube and Google searches. The only lab equipment I own is this funnel, a flask, and a vacuum pump. The only relevant PPE I own is a respirator, various gloves, and some chemical safety goggles.