I last used a magnetic stirrer around 30 years ago, it was an industrial model capable of handling 20 litres of solution; there was another stirrer which I never got to use which handled up to 500ml. Back then the cost of magnetic stirrers in this country was prohibitive, now it seems as though every person needs a magnetic stirrer for all sorts of things, including cooking food; which I find a fascinating development of this probably once pure scientific tool.
I would like something that can handle up to 2.5 litres of solution, which is when I mix chemistry for paper developer. Looking around the web at Australian based suppliers, there seems to be a plethora of units with varying degrees of doodads which, within reason, seem surplus to my requirements, or maybe not.
The main extra seems to be one with heating capability, which invariably has a temperature sensor held by a swinging frame into your solution. Photographically speaking I pretty much use 50ºC as my starting temperature using the inbuilt temperature monitor (Tel-Tru) on my darkroom over the sink water pipe. Fill whatever container I'm using to approximately 65% of the intended maximum and start from there. I have a standby jug of water with the same temperature with which I rinse my containers out after depositing dry chemistry into the solution; placing that rinse into the solution.
My 3 litre glass mixing container calibrated to 2500ml, is pretty much what I use for paper developer and such, it has a base of 115mm diameter and would work perfectly with this unit. For film developers I work from 500ml through to around 2000ml with three sizes of containers. These days I'm mixing chemistry close to once a week, mainly film developer, and although I don't mind spending 30 minutes or so getting all chemistry into solution using a Paterson hand mixer (on my third one in 40 years), I could be doing something else in the darkroom while the chemistry was being mixed into solution.
On the other hand spending a bit more, adds a heating element into the unit as well as temperature monitor and so on. My question here is this:- is having a heating possibility by those who have that possibility useful, or something you don't use much, if at all?
Last but not least, is having different sized stirring bars a requirement, bearing in mind my differing solution capacities being stirred? Or is a bigger one in small solutions running slower, just as good as a small one going like the clappers? Perhaps there is a stirring bar size to revolution ratio formula, which indicates which size range of stirring bar is better suited to a certain range of solution size? Thinking of vortex size here.
I would like something that can handle up to 2.5 litres of solution, which is when I mix chemistry for paper developer. Looking around the web at Australian based suppliers, there seems to be a plethora of units with varying degrees of doodads which, within reason, seem surplus to my requirements, or maybe not.
The main extra seems to be one with heating capability, which invariably has a temperature sensor held by a swinging frame into your solution. Photographically speaking I pretty much use 50ºC as my starting temperature using the inbuilt temperature monitor (Tel-Tru) on my darkroom over the sink water pipe. Fill whatever container I'm using to approximately 65% of the intended maximum and start from there. I have a standby jug of water with the same temperature with which I rinse my containers out after depositing dry chemistry into the solution; placing that rinse into the solution.
My 3 litre glass mixing container calibrated to 2500ml, is pretty much what I use for paper developer and such, it has a base of 115mm diameter and would work perfectly with this unit. For film developers I work from 500ml through to around 2000ml with three sizes of containers. These days I'm mixing chemistry close to once a week, mainly film developer, and although I don't mind spending 30 minutes or so getting all chemistry into solution using a Paterson hand mixer (on my third one in 40 years), I could be doing something else in the darkroom while the chemistry was being mixed into solution.
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On the other hand spending a bit more, adds a heating element into the unit as well as temperature monitor and so on. My question here is this:- is having a heating possibility by those who have that possibility useful, or something you don't use much, if at all?
VEVOR Magnetic Stirrer Hot Plate Digital Hotplate Stirrer 2000/3000RPM 1/2/3L | eBay
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Last but not least, is having different sized stirring bars a requirement, bearing in mind my differing solution capacities being stirred? Or is a bigger one in small solutions running slower, just as good as a small one going like the clappers? Perhaps there is a stirring bar size to revolution ratio formula, which indicates which size range of stirring bar is better suited to a certain range of solution size? Thinking of vortex size here.