Stir Plate

[Cloud Surfer]

I’m looking for a large size stir plate that will hold a 5L size flask. Does anyone have any recommendations?

 

[Coalminer]

https://www.kegland.com.au/compact-adjustable-magnetic-stirrer-machine.html

 

[mje1980]

I dont think that’ll hold a 5 litre flask. I have one and it’s ok for 3 litres but I don’t know about a 5 litre. Others may have tried it though

 

[MHB]

Most "value" stir plates are really only good to a liter or two. Some mid priced ones are OK up to 3.5L but anything that will get a real spin going in a 5L batch will cost.
It all depends on what you are trying to achieve, if its a vortex that is sucking air all the way to the bottom, you need a powerful stirrer, if its just to keep the yeast in suspension then its a lot easier. A bit of playing around with the length of the stir-bar and the speed will give you what you need, even from quite a small stirrer.
To get the best growth of yeast keeping plenty of air in solution helps, an air-stone with a HEPA filter and enough stirring to stop the yeast settling will see you getting plenty of healthy yeast. A couple of drops of antifoam wouldn't go astray, lets you keep pumping in the air without the wort foaming out the top.
Mark

 

[Cloud Surfer]

https://www.kegland.com.au/compact-adjustable-magnetic-stirrer-machine.html

Yes I contacted KL about their stirrer because I wasn’t sure it would handle a 5L. They sent me back a photo that showed the flask was twice as wide as the stir plate. If I can’t find any reasonably priced plates that can handle a 5L, I’ll buy the KL one and modify it.

 

[kadmium]

Just build one. I built one easy lease.

 

[Coalminer]

I dont think that’ll hold a 5 litre flask. I have one and it’s ok for 3 litres but I don’t know about a 5 litre. Others may have tried it though

Well I have one and a 5 Litre flask and it will hold a 5L flask otherwise I would not have suggested it

 

[mje1980]

My old digital one could easily handle 5L and was whisper quiet. Sold it when I had a few years out of brewing unfortunately. The KL one is noisy as hell ( need to use it in the garage ) and fairly basic in design but does work. My flask is domed on the bottom and its a pain in the arse to get the stir plate going.

 

[Coalminer]

My old digital one could easily handle 5L and was whisper quiet. Sold it when I had a few years out of brewing unfortunately. The KL one is noisy as hell ( need to use it in the garage ) and fairly basic in design but does work. My flask is domed on the bottom and its a pain in the arse to get the stir plate going.

Suggest you send it back. I have 2 and they are very quiet

 

[kadmium]

I built mine for about $20 and a new housing to fit a 5L flask would be about $10

Building them is very easy and cheap.

 

[Cloud Surfer]

I built mine for about $20 and a new housing to fit a 5L flask would be about $10

Building them is very easy and cheap.

View attachment 119210

That’s a clever way of building one.

 

[kadmium]

Yeah I'm a pretty clever bloke. What's that saying? FIGJAM?

Yeah I couldn't figure out a good housing and then that was on special at slaveway and I thought for $5 why not try it.

I can show you how I built it if you would like, made a few changes which helped alot with it. It's very simple but stirs 3L with a vortex down to the magnet. Took a little fiddling but it's a ripper now.

 

[CaptainMachSnot]

@kadmium , I'd be keen to see how you made it. Been thinking that this might be my next acquisition, but a bit put off by the few hundred price tag, and i thought that the cheap ones probably wouldn't be worth getting. Did you make it out of a computer fan?

 

[kadmium]

Yeah mate.

I bought a computer fan from local computer shop, was about $10

LED dimmer was about $6

Magnets were about $8

You can use what ever enclosure you like. The Tupperware was on sale at woollies for like $5

I had an old 12v power supply from a router, you want something with a few amps to ensure constant supply. You can't go too high in amps because it only draws what it needs so anything 12v will be good.

Hook the power to the dimmer, and dimmer to the fan.

Set the fan to spin and trace a dot in the centre so you know where the dead middle of the fan is.

Use a ruler and make a straight line along the fan. Get your rare earth magnets (i used button magnets from online I can let you know the specific ones if you want) and set them up.

Mine stuck to the fan by magnetism but sometimes they don't.

I used a holesaw to make a hole the size of the fan, and then those 3m Velcro strip's to fix the fan to the inside of the lid. This gave the fan clearance so the magnets didn't stick out the top of the lid.

I drilled some holes in the box to allow air to flow, as the fan is obstructed by the flask.

I also made some holes through the box to feed the power supply, and I can coil it all up inside the box for storage. I'll take some photos for you.

 

[Teebs]

Stir plate and flask in action
Bought both from KegLand
Works great

 

[CaptainMachSnot]

Cheers, just hadnt seen a dimmer like that one before, wasnt sure what it was. I have loads of electrical crap at home (electrician by trade), so power supplies aren't an issue, just dont have an ELV dimmer. Was thinking of getting a pot to do it with, just not sure of the current draw. Haven't looked too far into it yet. The cheap fans on ebay don't really give proper specs (at least the ones i have looked at), and havent seriously chased them down yet. Seen quite a few of these made, and when you said you made a few changes, wondered what they might be.