Tried a larger magnet but i think the bottom is too thick. Thought about getting a Black Maxx but too $$s. any ideas?
what type of bar and what type of plate. How much volume did you have in the flask? Also do you know how many volts your stir plate is putting out. 6/9/12?
Most of the homebrew comercial stir plates use two small magnets that only hold a 1" bar well. Though a 1" bar will not stir 5l by any means.
Best option would be to look for a lab surplus stir/hot plate since they have an actual bar magnet and will work with bars from 2mm to 3inches. If that isn’t possible you can build one using 2 bar magnets (think for expansion for larger bars) that will hold anything from 1inch to how ever big the bar magnets span.
My stirplates are from http://www.stirstarters.com/. 1" stir bars handle a 4.5L starter in a 5L flash just fine.
These also use 2 small, but powerfull Neodynium magnets. Yeah, it can do a 5L starter. I know this works!
I use the same stirplate, but have a hard time getting a dimple in a 4 L starter without throwing the 1" stir bar.
I think it depends on the flasks you have. The 5L ones I have luckily have a very flat bottom and I can usually take them almost all the way up to the highest speed without throwing them.
My 2L flask, on the other hand, has a very slight convex bottom and will easily throw the stir bar at anything over the very lowest speed.
I just got a stirstarter and this thing ROCKS. I can get a nice vortex using a 1" bar, but the larger bar wont work very well.
+1 to stirstarters.com
I have one from stirstarters and to use it with a 5L flask I have to prop up the flask so the bar is on the side and not the center, because of the hump in the middle of the flask. I just use the stir bar that came with it.
if it wont get enough traction on the bar you can try taking the top off of the stirplate(if it has one) to get the magnet a little closer to the stir bar.
Anyone tried this with a carboy?