Erlenmeyer Flask bottom warped?

[king5899]

I used a new 2L flask for a starter 2 batches ago where I boiled in a pot and transferred the wort into the flask. The stirbar worked great at full power. My next batch I boiled in the flask and then cooled. When I started the stirplate I could barely get the whirlpool going because it kept throwing the bar off at maybe 50% power. I noticed the flask bottom doesn't seem flat. Could the direct heat have warped the bottom of the flask preventing the stir bar from staying in the center at higher speeds?

 

[doug293cz]

I used a new 2L flask for a starter 2 batches ago where I boiled in a pot and transferred the wort into the flask. The stirbar worked great at full power. My next batch I boiled in the flask and then cooled. When I started the stirplate I could barely get the whirlpool going because it kept throwing the bar off at maybe 50% power. I noticed the flask bottom doesn't seem flat. Could the direct heat have warped the bottom of the flask preventing the stir bar from staying in the center at higher speeds?

No, you need to get the glass very hot to deform it.

Brew on

 

[Gameface]

Some flasks have flatter bottoms than others. But no, you did not warp borosilicate glass. No chance of that.

How did you store your spinbar? I've recently learned that they lose magnetic strength if exposed to strong magnets for too long. I used to keep my stir bars on my fridge door stuck to a neodymium magnet and after a while they started getting thrown. Had to buy new spin bars and now I store them in a small tackle box.

 

[passedpawn]

Some flasks have flatter bottoms than others. But no, you did not warp borosilicate glass. No chance of that.

How did you store your spinbar? I've recently learned that they lose magnetic strength if exposed to strong magnets for too long. I used to keep my stir bars on my fridge door stuck to a neodymium magnet and after a while they started getting thrown. Had to buy new spin bars and now I store them in a small tackle box.

Why not just store the stirbar in the flask?

 

[Gameface]

Why not just store the stirbar in the flask?

Now you tell me?

 

[passedpawn]

Now you tell me?

Better late than never

 

[king5899]

OK good to know, I was about to buy a new flask. I stored my stirbar on the stirplate. I have a few new spinbar, maybe I'll try them.

thanks

 

[DurtyChemist]

Also, you might want to turn the speed down and see if you slowly increase it if the stir bar stays in place. It could have just been going too fast. I've never had my stir plate throw a stir bar unless I started it too fast and added the stir bar.

 

[Bellybuster]

quantity of liquid can make a big difference as well. When my flask is more full it holds the bar better than when not.

 

[beergolf]

You only need to spin a little. A good dimple on the surface is sufficient. On my stir plate I usually use about 1/4 speed. No need to go full blast or have a huge vortex.

 

[b-boy]

I highly recommend these. They never get thrown. They are a little bit noisier though.

https://www.southernlabware.com/ind...gle_shopping&gclid=CLOY-ZXI_8kCFQ2OaQod1nEPZQ