Another 45 litre Igloo Mash Tun

[FutureBrewer]

Hi all,

Inspired by PDTNC's recent mash tun build and a desire to go all-grain, I thought I'd have a go at making my own mash tun from an Igloo cool box.


Igloo Ice Cube 48QT with stainless ball-valve and adaptor

I bought the cool-box new from Ebay and ordered the ball-valve (part no. 16829), hose-tail (part no. 14558) and adaptor (part no. 7786) from BES.


Copper tube, elbows and tees

I had some 22mm copper tube knocking about from a DIY plumbing job I did a years ago. So, using a pipe cutter, I cut:

4 x 23cm lengths
5 x 5.9cm lengths

And from some 15mm pipe I cut:

1 x 3.2cm length for the outlet tail.

From Wickes, I bought some end-feed solder joints:

4 x 22mm 90 degree elbows
4x 22mm Tees
and
1 x 22mm to 15mm Reducing Tee


Measuring up...

I wanted to get an even distribution of tubes on the floor of the mash tun, but because this arrangement doesn't leave any room for another joint, I cut down one end of two of the 22mm tees and both 22mm ends of the reducing tee, putting two short connecting tubes in between:


Custom Tees for outlet

Spot on!


Finished manifold... besides sawing the slots

For the cool box, I measured 4cm from the bottom on the thinnest part of the wall (recessed area) and drilled a small pilot hole, making sure that it tallied up with the inside measurement.


Pilot hole

Satisfied with this, I drilled a second hole big enough for the Q-max shank:


Another hole

Then, Q-max'd a hole for the adaptor:


Q-maxing a bigger 'ole




Adaptor hole

The Q-max that I have is 20.4mm, which to be honest is barely big enough for the adaptor, but it DOES fit:




Adaptor

And here's the manifold in place:


Manifold

I haven't soldered any part of the manifold and I'm not sure if I will - it holds together pretty well without, and it'll be easier to clean this way.

Using the BES fittings means that the valve handle is quite close to the wall of the mash tun (in fact, the picture makes it look closer than it really is...) but it's not a problem


Ball-valve & hose-tail

So, besides sawing a load of slots in the manifold, I'm officially ready to go all-grain!


Mash it up!

Cheers,
FB.

[Tron]

Great stuff, i have exactly the same mash tun and its great, only problem i do have with it, is that i only do around 23 litre batches and i think it could easily hold x2 if not x3 times the grain bill, so you end up with having quite a lot of headspace and lose 3/4 degress over a 90 minute mash, i also started putting towels on the top and wrapping up the valve as that is a great big heat sink! so now only loses around 2 degrees.

The remedy of course is i need to get a bigger boiler

[richc]

I converted one of those this weekend as well, my only difference was I didn't do your clever bit with the outlet so had to go for a simpler manifold design because I couldn't fit the T joints into that sort of layout. Nice work there and if I ever need to replace the manifold I'll copy your trick.

[WishboneBrewery]

Nice going, looks good. I built the one for Rob from www.hopzine.com but haven't got round to doing my own yet.

[jmc]

Great stuff, i have exactly the same mash tun and its great, only problem i do have with it, is that i only do around 23 litre batches and i think it could easily hold x2 if not x3 times the grain bill, so you end up with having quite a lot of headspace and lose 3/4 degress over a 90 minute mash, i also started putting towels on the top and wrapping up the valve as that is a great big heat sink! so now only loses around 2 degrees.

The remedy of course is i need to get a bigger boiler

Hi Tron

I too have a cooler mashtun that's too big for my 23L brews, however I followed advice here and I found that having a thin mash and strapping down lid really helped.
See thread Mash Tun

+1 for the insulation as well. I use bubble wrap on the tap/heat sink.

ATB John

[retourrbx]

QUOTE "For the cool box, I measured 4cm from the bottom on the thinnest part of the wall (recessed area) and drilled a small pilot hole, making sure that it tallied up with the inside measurement."

Is this the optimum distance - is it measured from the outside, and also, is it measured from the flat surface that the box is sitting on or, from the bottom of the plastic itself?

Cheers

[FutureBrewer]

Is this the optimum distance - is it measured from the outside, and also, is it measured from the flat surface that the box is sitting on or, from the bottom of the plastic itself?

It was the optimum distance for me... With the 22mm tube manifold sitting on the bottom of the coolbox, I measured the position of where the reducing tee touched the wall. I measured this (from the top) on the outside of the box, but because of the curves, angles and handles, it made it difficult to mark the position. So, I measured down on a 'straighter' area, and measured up with a steel rule. 4cm if I remember correctly

And yes, for marking the pilot hole, I measured up from a flat surface (a table) rather than the box itself...

Hope this helps!

Cheers,
FB.

[HopZine Rob]

I've found I've lost no heat during a 60min mash with the Igloo cooler PDTNC built me. Its a great piece of kit. I've only brewed 5.2-5.4% pale ales so far but its good to know I can whack in more grain and get a big old 7% IPA no problem.

[dazer23866]

When you saw the slots will you use a junior hack saw

[retourrbx]

When you saw the slots will you use a junior hack saw

angle grinder will make quicker work of it - need the right size disc though

[smeggedup]

hi
nice build
could you tell me how the hose bar piece is conectted to the tap is it just screwed in looks that way ?
cheers

[smeggedup]

hi
could some also give a link to the adaptor as the part number shows afew results
wanting 1/2inch or 15mm for my build
cheers

[FutureBrewer]

could you tell me how the hose bar piece is conectted to the tap is it just screwed in looks that way ?
cheers

If you mean the hose tail on the front of the tap, then yes it screws into the tap.

could some also give a link to the adaptor as the part number shows afew results wanting 1/2inch or 15mm for my build
cheers

The adaptor is part no. 7786 from BES which is 15mm to 1/2". 15mm connector with nut & olive inside the coolbox to attach the manifold to. 1/2" BSP thread on the outside to connect the tap to...

When you saw the slots will you use a junior hack saw

I originally planned to use a full-size hacksaw, but I think I'll be borrowing an angle-grinder (as retourrbx suggests) because me arm will probably drop off after sawing all those slots otherwise

Hope this helps

Cheers,
FB.

[johndavies]

I would like to make this mash tun, would a dremel cutter be ok to cut the slots?

if so what cutter would I need to use?

[Dave1970]

I have one of these too, I lost 2 degrees over 90 minutes on a 7kg mash the other day. One thing that might help a bit is to pull the little bung in the lid and squirt it full of builders expanding foam.