I have a couple of stir plates made, but before I plunk down the money for a couple of erlenmeyer flasks, I have some 1gallon pickle jars that I’d like to try. Since the jars have concave bottoms, I’m told I should use dumbbell stir bars. The ones that I’ve found run $19 each! Any cheaper sources?
Have you checked to see if a regular stir bar works? They do with mine.
No, I haven’t. Are you saying your jars have concave bottoms? That would be awesome if a regular stir bar would suffice. What length vstir bar do you use? Does your stir bar have the ring around the center.
Yeah, I just use gallon jugs and 1/2 gal growlers for my starters. The bar is 25 mm with a center ring. http://www.coleparmer.com/Product/MONO_MOLD_small_sup_reg_sup_small_Standard_Stir_Bar_with_Spinning_Ring_1_L_x_3_8_dia/EW-08550-00
More than anything, it depends on the placement of the magnets, and how strong they are.
We got ours from http://stirbars.com/
I just noticed they have a $50 minimum order, but we did a club buy. Maybe that’s an option for you.
I have one, I used it once; too noisy. Pm me and I will send it to you free.
If it’s too noisy or the bottom is concave, put an o-ring on each end. The ones that are used for the dip tube of a Corny keg work perfect.