Sciencemadness Discussion Board

porous plate

Magpie - 22-12-2010 at 16:39

I occaisionally see a "porous plate" specified in a procedure, especially in some of the older ones. It's usually used for drying wet crystals.

I don't know exactly how these are made but I'm thinking that one could easily be made with a potter's wheel and then fired in a kiln. I'm thinking that a mix of 50% kaolin clay, 25% feldspar, and 25% SiO2 would make a nice white plate. I don't know what would be the best proportions for the right porosity. Any suggestions?

not_important - 22-12-2010 at 17:22

You've got the idea, just about any general purpose clay works and fireclays were common. Also for those without facilities for making their own, pottery supply shops often carry unfired greenware, bisqued, or fully fired plain unglazed tiles such as http://www.dogwoodceramics.com/Products/unglazed_ceramic_bis...

I'd just wedge the clay then roll it out, with an old rolling pin if nothing else.

The optimal pore size varies some with the product crystal size and shape, but doesn't seem to be too critical.



Sedit - 22-12-2010 at 18:08

I have a ton of these since I have a kiln and much experience in ceramic works. Honestly, I love them. There are times where they shorten a process so much that I couldn't live without them. My suggestion since its for chemical work is to just go with Porcelain since its some of the highest quality clay around and its pore structure is quite small while still allowing substances to dry quickly.

Take care to only fire the clay to bisqe ware temperatures to avoid vitrification else all your work would be in vain and you would have nothing more but a piece of glass.

Magpie - 23-12-2010 at 16:48

Thanks to both of you for the good suggestions. And Sedit, I'm glad to see that somebody is actually putting porous plates to good use.

I do think I will investigate what my local pottery shop has for bisqueware before trying to make one of my own.