i have concerns about whether a magnetic stirrer-heating mantle combo or an overhead stirrer (w/ separate heating mantle) is appropriate to my application. the stirrer is required to stir an amalgam of zinc and [insert precursor here] during a reflux of 12+ hours.

my concern is that if the amalgam + precursor mix becomes too viscous during later stages of the reflux, then the magnetic stirrer will not do its job correctly and/or get stuck in the leftover sludge. the possibility of this is currently weighted against the increased cost of an overhead stirrer, so both sides of the coin have disadvantages. any suggestions/experiences to share?

Improvised Overhead Stirrer on rhodium's page.

Obviously some people are swearing by cheap methods when they're making enuff to buy real overhead stirrers.
*GRinZ*
=þ