Icebox ~ Mash-tun woes oh woe is me

[droid]

Hi fellow brewers, looking for some help regarding my icebox come mash-tun...

After being inspired during my first attendance of the Xmas in July Vic case swap I came home determined to increase output. For a week after work I built up a copper manifold to fit my evakool ice box.

On Saturday brew day I filled it with water with a temp in the region of 70c. The internal walls and base ballooned up pushing the manifold up on one side - FFS

A guy at work suggested making a small hole in the outer side of the cooler, like 1/8th or 3mm to let the pressure out?

I'm spewing at the mo coz I want to use the manifold and don't want to buy another cooler...

Any ideas gratefully received

(Evakool responded to much the same in an email stating high temps are not recommended)

 

[Matplat]

I think your mate is on the right track.... but it depends on what the wall thickness is made of and how hard it is for the air to reach the hole. The problem would at least become transient.

Give it a go, if it doesn't work, plug the hole with epoxy.

Apart from that..... brace the inside of the esky somehow?

 

[droid]

Thanks Matplat, I'll give the hole a try somewhere - thinking higher outer centered?

bracing could be a goer if something simple and quick doesn't work

 

[antiphile]

I have to admit I like Matplat's second idea. I shouldn't be too difficult to make a "basket" to sit the esky in (even with just inexpensive 25 X 13 ml non-structural pine from bunnings).

 

[benno1973]

I have to admit I like Matplat's second idea. I shouldn't be too difficult to make a "basket" to sit the esky in (even with just inexpensive 25 X 13 ml non-structural pine from bunnings).

It's the internal walls ballooning up though, so the bracing would need to be inside the esky. That would require a bit more effort...

 

[Mardoo]

Seems pretty amazing that they're ballooning under the weight of the water and grain. The only bracing I can think of is stainless strips bolted through the bottom/walls to a similar strip on the outside.

I've got a Techni-ice, which is essentially one piece, no liner. Sounds like gas trapped between the liner and insulation, so your vent hole/s may need to go through to just below the liner. Pure speculation on my part though, so take it for what it is.

 

[antiphile]

Whoops. Sorry mate, I missed that.

 

[pcqypcqy]

I have similar issues with a 20 litre esky I use as a HLT. I think the lining/insulation doesn't like the temp, and it swells. Settles down a little afterwards but it's permanently bulgy on the inside.

If you're just worried about the manifold moving, could you brace it using your manifold? Swap out the corner pieces for tees, and then use a short length of copper and an end-cap so that the manifold is held in position against the walls? Shouldn't move at all then.

 

[pcqypcqy]

Seems pretty amazing that they're ballooning under the weight of the water and grain. The only bracing I can think of is stainless strips bolted through the bottom/walls to a similar strip on the outside.

I've got a Techni-ice, which is essentially one piece, no liner. Sounds like gas trapped between the liner and insulation, so your vent hole/s may need to go through to just below the liner. Pure speculation on my part though, so take it for what it is.

I don't think it's ballooning under the weight, it's the temperature doing things to the lining and insulation.

 

[barls]

mine did that. i drilled the opposite side. then filled with 80+ water and sat a brick on top of the bulge to flex it back down.
once cool i filled with expanding foam and haven't had a problem since.

 

[droid]

I have similar issues with a 20 litre esky I use as a HLT. I think the lining/insulation doesn't like the temp, and it swells. Settles down a little afterwards but it's permanently bulgy on the inside.
If you're just worried about the manifold moving, could you brace it using your manifold? Swap out the corner pieces for tees, and then use a short length of copper and an end-cap so that the manifold is held in position against the walls? Shouldn't move at all then.

The walls balloon out but I'm not really bothered by that, the base however, balloons up and pushes the manifold into the air on the end that is not fastened to the box. Initially I thought the manifold was floating (I never got around to putting grain in it Mardoo - thankfully) so I tried pushing the end of the manifold back down and it wasn't budging

mine did that. i drilled the opposite side. then filled with 80+ water and sat a brick on top of the bulge to flex it back down.
once cool i filled with expanding foam and haven't had a problem since.

So how about a small hole around the back under a hinge. Put some water in see what happens. If it buldges then pack it internally / brace it ... Empty let cool, then get some expanding foam into all areas, try again

Worst scenario, permanent bracing inside but **** I'd have to ask meeself some hard questions then

Cheers for all the ideas and help, I shall report back

 

[droid]

reporting in :

Drilled a hole under each hinge and held the manifold down with a brick as the water filled. Once the water was around the top of the manifold I pulled the brick and it stayed there. The walls still ballooned and the base was not flat but I reckon good enough.

Does anyone mash with their slots facing up? I thought I read that John Palmer said it doesn't matter which way they face, though I've always had them face down. Face up with the uneven base might be better - what say yee?

@pcqypcqy - found a couple of tees rattling around so next time I'm in Bunnings I'll grab a couple of caps and brace the ends as you said, can't see a problem with it, cheers mate and cheers all

 

[Ducatiboy stu]

I would tend to have them facing down so the grain doesnt block them up...


But then again I solved that problem by going to a false bottom B)

 

[pcqypcqy]

In theory facing down should syphon more wort out of the mash tun, leaving you less dead space. Sounds good in theory but it would only take on slot to suck in a bit of air somewhere before the vacuum is lost, so whether it makes an actual difference or not remains to be seen.

I haven't tested it on mine, but I end up with about a cup of liqour left when I have the slots down. I might try it slots up next time for fun.

 

[dicko]

I have a mash tun with a manifold with the slots actually cut in the sides of the pipe rather than the bottom or top.

My son uses it and it works fine but the drawback is mash tun deadspace... at least a couple of litres from memory.

 

[Adr_0]

Um,just a quick one...

Could the ballooning be caused by water coming into the walls of the esky? Could it alternatively be caused by the wall softening? I would've hopes is noted softening, but would've think it's more likely you have water entering your walls.

 

[pcqypcqy]

I've had small amounts of water entering the wall around the tap outlet, but never enough for it to balloon due to water pressure. Though thinking about it, I don't think it would balloon for this reason because the pressures would equalise on both sides of the wall, hence there'd be no force there to cause the ballooning.

In any case, I've carefully drilled holes in the outer lining only of my mash tun and HLT so that when they're sitting flat they should drain freely. You need to be careful when drilling this to make sure you don't push the drill bit through the inner lining.

Cheap esky insulation and lining warping due to the temperature, this I'm very familiar with. You can hear my HLT warp and crack as you throw the sparge water in. Only ever a few drips coming out of the drain holes I installed so I'm pretty sure it's all temp.

 

[droid]

sorry i missed these posts...

the icebox came with one deep and one shallow cage for internally holding foods or whatever. i have done two brews with the icebox now and while the water is filling up I put the cages in on top of the manifold to suppress any ballooning. i have drilled four external holes making sure not to go through the internal wall. all seems to be fine tho yet to taste the beer, not sure i would do a super clean lager in it. i guess the easy test would be to put some water at 67 through the tun and put it in the fridge and taste it - der brain, prolly should have done that initially

i think the expansion is due to temperature, as the walls heat up they have to also expand so with no-where else to go they balloon out. it seems the walls just have a cavity between them. the holes seem to have helped but i am loathe to drill any down around the base as surely muck could find its way inside and inbetween the walls ... i'd never get it out

seems all good presently and thanks for the advice/thoughts