Plastic Alternative To 3/4" Brass Nipple Needed For Mash Tun

[hefevice]

OK, I screwed up (I think).

I attempted to convert a 55L Willow esky into a mash tun, complete with a MashMaster bi-metal thermometer. To mount the thermometer I had the "brilliant" idea of drilling a hole for a piece of 3/4" brass nipple, into which I tapped a 1/2" (BSP) thread for the thermometer.

What I forgot was that brass is a pretty good conductor of heat. My trials with heated water only showed a pretty high loss of about 5 degrees C over an hour (starting at 72.5C, volume of 20L). I suspect I am losing a fair bit of this through the brass (and increased conductivity to the actual body of the thermometer).

Spigot also uses brass nipple, so it is possible I am also losing some heat there.

So, does anyone have any suggestions on where I can get my hands on suitable 3/4" plastic nipple capable of handling elevated temperatures?

 

[DJR]

I'd say it's probably not the brass that you are losing heat through. You are probably losing it via the top. Try drilling a couple of holes in the lid and filling it with some spacepacker foam (selley's space invader or similar). That or cut a piece of styrofoam (a fish/vegetable packing box) to the appropriate size to float on top of the water/mash.

 

[lonte]

I got my stuff from an Irrigation shop (specifically "The Irrigation Shop", Moss St, Slacks Creek). Not entirely sure what temps they're rated too but they're still providing great service in my mash tun after over a year.

 

[hefevice]

I got my stuff from an Irrigation shop (specifically "The Irrigation Shop", Moss St, Slacks Creek). Not entirely sure what temps they're rated too but they're still providing great service in my mash tun after over a year.

Black poly-pipe type fittings?

 

[hefevice]

I'd say it's probably not the brass that you are losing heat through. You are probably losing it via the top. Try drilling a couple of holes in the lid and filling it with some spacepacker foam (selley's space invader or similar). That or cut a piece of styrofoam (a fish/vegetable packing box) to the appropriate size to float on top of the water/mash.

Yes, I was also suspicious of this, and the fact that there was a lot of air between the top of the water and the lid (only just over a third full). Also not sure how much lag the actual grain will provide, so my test conditions may well be a lot worse than real world.

Will definitely fill the lid with spacepacker foam...good idea!

 

[kook]

I really doubt thats how you're losing that much heat. When you drilled it, was there insulation material inside the walls?

Also, remember that your results with water will be a bit different to a mash. The grain itself will help to hold the temperature.

I lose aprox half a degree per hour with an esky (57L round KeepCool) and I've got a long SS shank coming out of it as well as a mashmaster thermometer.

 

[hefevice]

I really doubt thats how you're losing that much heat. When you drilled it, was there insulation material inside the walls?

Yup, it was insulated. Looks like I need to re-run my tests.

 

[PostModern]

I'm with kook, run your tests with a mash.

 

[blackbock]

Black poly-pipe type fittings?

I have no advice on the heat loss, but the black poly-pipe connectors might solve your connection problem.

 

[lonte]

Black poly-pipe type fittings?

that's them