Tuesday, March 08, 2011

The Sand Bath - An Alternative to the Oil Bath

Yes, I am still alive! I have been out of the lab for a loooong time so the inspiration hasn't been there. However, I am now finding myself in the lab again and it appears that I will get to stay there for a while. And today inspiration struck.
Let's talk about oil baths. Good way to heat stuff up in a controlled way, BUT, what a bloody mess they are. The oil becomes disgusting after a while, the glassware gets nasty, ocassionally oil baths break and make the mess from hell....
So whenever possible I use an aluminium heating block. However, we have a limited number of these in a limited number of shapes and sizes. When a heating block isn't available my next choice is a sand bath. These are traditionally used when you have to heat something to a ridiculous temperature that oil can't handle. However, I use them for any reflux (see picture). The problem with these things is that heat transfer isn't particularly effective so it's only really good for reflux and not for heating something at a well defined temperature below the boiling point. Also it can be quite tricky for the sand bath to heat up in a well ventilated fume hood so it is generally a good idea to wrap a bit of aluminium foil around the bath to get the heating going. D!