Bought a mash tun!

[oldjiver]

Sitting here with too much time on my hands, I have just bought online an IGLOO 400 5 (US) gallon cool box, the red and yellow one. It seems to get good reviews for holding heat and not warping. I have always used a sparging bag rather than a false bottom so this should suit well. I only do 3-4 gallon brews so it is big enough (cant lift any more as I am disabled).
Only problem may be the tap, its a push button one I think. Finding a proper tap for that size may be a problem, but as its going to be about three months before I can do a brew I should find something.

 

[oldjiver]

Adding to this..
For all of my mash tuns I have always made a piece of polystyrene that fits inside the tun. I put this in a plastic bag and push it down to just above the level of the mash. I find this greatly helps hold the heat in.

 

[Frogfurlong]

Don't know it myself but a bit of google-fu brought up this

http://www.onemansbeer.com/diy-mash-tun-parts/


Hope it helps you

 

[oldjiver]

Oh to be in America!! Dirt cheap tuns and all the bits!
But thanks for that, shows it can be done. I understand American pipe threads are slightly different to ours but should fit. Fingers crossed.

 

[oldjiver]

Hears another really usefull link

http://www.youtube.com/watch?v=rMUs8snP ... r_embedded

I was concerned that the gap between the walls might fill up with mash, but it appears the two sides meet where the tap is so it should be much easier to fit another tap.

 

[oldjiver]

Igloo tun arrived yesterday!! Seems good solid construction. Sides are solid foam filled. The lid is hollow which is disappointing. Also the bottom of the tun may be hollow, (stick your head in and hold it to the window you can see a bit of light where the bottom curves under). I can fix the top, dont know about the bottom. Tap hole is 3/4" across, thats standard 1/2"BSP. I havent got one of my plastic taps here to try as my gear is in storage waiting to move, will try later. Initially very pleased. Didnt cost me any real cash as thanks to this great site I sold some spare demijohns and a mill that covered the cost.!! (I will be getting my malt/hops from the sponsor!).

 

[rpt]

I'm guessing you won't lose much heat through the bottom as heat rises. This is why the lids are often hollow - they are sold to keep things cold so not much escapes up. Although the bottom is hollow it is always going to be used on a surface which will add insulation (especially if it's kept on the ground).

 

[tazuk]

here is mine i never had any probs yet :thumb:

 

[oldjiver]

Hi Tazuk, The first picture seems to show a blanked off hole?? where my push tap is. Can you explain please. Secondly are you using a brass tap? I am trying to locate a 1/2" bsp plastic tap as there seems to still be a debate about using brass. Thanks.

 

[rpt]

That just looks like he's taken the tap out before taking the picture.

Have you added lots of extra insulation to it? In the third picture it looks like it's wrapped in something.

 

[oldjiver]

That just looks like he's taken the tap out before taking the picture.

Have you added lots of extra insulation to it? In the third picture it looks like it's wrapped in something.

Yes I can see that now its been pointed out.!
Looks like cling film over bubble wrap? Would be a good idea to keep everything in place.

 

[oldjiver]

Anyone think of a reason I shouldnt use a brass tap like this? (I have one already)

 

[oldjiver]

Failure!! Not sufficient length of thread to get required washers on. Tried it with single plastic washer and it leaks. Start again

 

[oldjiver]

JUst noticed the lid has two small holes with pop studs in them. Just right for squirting foam filler in. Will do that some time.

 

[oldjiver]

Just finished adding a tap. Read a lot online about Brass fittings, and have decided personally I am happy to use them. Got all the bits from a local hardware store for about £9.00. Doesnt leak!! (thats why the pics are taken next to the sink, just in case). The lads at the store cut the copper pipe to size free on the promise of a pint when its made!! Will test for heat retention soon.

 

[oldjiver]

By the way, the tap will be disconnected when not in use. I would hate to bump it and tear it out of the plastic.

 

[oldjiver]

Heat retention......
Checked (150deg) after 1/2 hour lost 2 deg. After 1 hour 4 deg. Sides absolutely cold. Bottom tiny warm patch, will fix by standing on polystyrene slab. Lid was warm?? Must insulate with foam. Contacted Polycell some time ago asked if foam can was closed cell (good) or open cell (bad) .Answer 80% closed 20% open. So will probably use that. Luckily two plugs in lid come out for injecting.
Tap ... Red hot!! cant really do much about that? (bit of bubble wrap perhaps) (open to suggestions)
Did heat test now I have insulated the lid with Perlite. Preheated tun lost 0 degrees after 1/2 hour and 1 degree fahrenheit after 1 hour. :party:

 

[LeedsBrewer]

Is your test using the full amount of liquid you'd be using in a propper mash? If not then your figures will be out cos a half empty (or half full depending on your disposition) MT will lose heat quicker than a full one.

Also when it comes to doing your actual brew i would suggest preheating your MT several hours before with several L of water.

A preheated MT will not lose as much. :thumb:

 

[oldjiver]

Tested full to the brim and preheated. I have always wondered why a mash should hold heat better than water? A high mass is usually considered to hold heat best. Mass equals Volume x weight, and as water has higher mass than grain I would have thought the opposite would apply. I wonder if the theory started by being mixed up with the ENORMOUS mass of a brewery mash tun relative to the much smaller homebrew tun?
Worth a discussion?? :wha:

 

[oldjiver]

Apart from my "Dave Line" square tun when I started brewing, I have just used a FV wrapped up in anything I had to hand, bubble wrap, foam, blankets etc, or my thermostatically controlled boiler. As I mash at 156 for bitters and fill the tun with liquor I havent had any real; heat problems. But I think once the lid is foamed I will have a cracker here :