magnets inside fermenter - Neodymium no good?

[buckerooni]

So I got these, https://www.bunnings.com.au/everhang-12mm-rare-earth-disc-magnet-6-pack_p3690099 but see in other threads it's recommeded ones with teflon, like stirbars.

what's the issue with Neodymium ones, corrosion?

as I will have up to 150g of hops in a bag, I'll probably go with something stronger than stirbars: https://magnet.com.au/neodymium-disc-25mm-x-2mm-teflon-coated.html

 

[MHB]

The Nd is part of the alloy that makes up the magnet, they are coated with Nickel, so the question is really - Nickel no good?
Short answer is Ni is pretty nasty in other than trace amounts.
Mark

 

[buckerooni]

thanks for the info, have ordered these teflon coated discs - https://magnet.com.au/neodymium-disc-25mm-x-2mm-teflon-coated.html.

will keep the existing ones out of the wort!

 

[sixfignig]

I just want to know where you got that TC dump valve assembly? @buckerooni

 

[awfulknauful]

I just want to know where you got that TC dump valve assembly? @buckerooni

https://aussiehomebrewer.com/threads/modding-the-fermentasaurus.98202/page-2
The new Fermenter King comes ready to adapt. I think the 60 litre is out now as well.

 

[buckerooni]

yep that's the link! I think it's a great mod, I only use it for dumping yeast and it's a bit questionable about reusing the yeast, it does get a bit errr....squirty.... but I haven't spent any time trying to solve that problem yet. I used QD fittings, so a collection bottle with a QD fitting would probably work.

I have a 55L fermzilla, so this will work! https://www.kegland.com.au/fermzilla-conical-2inch-tri-clover-harvest-adapter.html

 

[Mrdanielpcollins]

thanks for the info, have ordered these teflon coated discs - https://magnet.com.au/neodymium-disc-25mm-x-2mm-teflon-coated.html.

will keep the existing ones out of the wort!

Hey, do you need two of these magnets or an you use one on outside and have a metal disc in a hop bag?

 

[buckerooni]

what kind of metal disc? none of my stainless washers (316) would work.

 

[MHB]

Use a stir bar if you have one, they are pretty strongly attracted to other magnets, especially strong ones.
You would get away with a bit of round bar inside a piece of food grade plastic tube that is maybe 20mm longer (10mm at each end) than the bar, fill the ends with food grade silicone. Make sure you let the silicone set fully.
Mind you Teflon will be better its about the least reactive material known, its tough, chemically inert, temperature stable... everything you could ask for really.
Mark

 

[Kev R]

what kind of metal disc? none of my stainless washers (316) would work.

304 SS is a little magnetic, SS rulers are are very magnetic, you could buy a cheapy and cut it up?

 

[wide eyed and legless]

304 SS is a little magnetic, SS rulers are are very magnetic, you could buy a cheapy and cut it up?

Trouble is cutting it up disrupts the surface and the mild steel comes through. Magnet on either side is the go.

 

[YAPN]

That's strange.

I've never had a hop sock that sank down onto the yeast cake. Mine have always floated on top. I use generic brand pantyhose, neutral colour, with up to 100gm of pellets.

 

[buckerooni]

That's strange.

I've never had a hop sock that sank down onto the yeast cake. Mine have always floated on top. I use generic brand pantyhose, neutral colour, with up to 100gm of pellets.

the idea is to control hop contact time in the wort with no O2 ingress.

with certain ferments, I find sometimes it takes multiple extra days to pass the diactyl test, and I want to ensure I can control hop contact time and mean you can experiment with early ferment VS late ferment dry hopping.

 

[MHB]

Having a think about what you are trying to do, you could tether the magnet inside the fermenter, find a way to attach a bit line to the lid of the fermenter and get a magnet with a hook or loop on it (googled magnet lifting hook and found plenty) like this

Shouldn't be too hard to arrange it so the tether stops the magnet falling into the brew. Some of the ones from Google had like 50kg lifting capacity, a magnet outside or even a bit of iron should be all you need.
Mark