Thermopot Bottom Drain Options

[YeastFace Brew Co.]

I have recently acquired a thermopot which I plan to convert into a MT when I've moved house (Probably January). I've also for 2 pots which I will convert to HLT and Boiler, but I've decided what I'm doing with these.

I'm trying to decide on draining method as I hope to purchase all the bits over the coming months.

There's a wealth of information already on this site and others, but I wanted to collect some thoughts/experiences in one place.

I'm settled on a bottle drain, but can't choose between central or offset positioning of the skin fitting.

What are the pros and cons of each option?

I'll be converting this myself, possibly with the assistance of either my Dad or Father-In-Law who are both more handy than myself.

TIA.

[Jocky]

I have a centre drain. Can't tell you if a side drain is better - with a false bottom over it I doubt there is any difference.

[JamesF]

I'm in the same position of working out how I'm going to assemble my new mash tun at the moment.

I think the possible advantages of a drain nearer the edge of the base is that there's less cutting to do and you can tip the mash tun to finish draining it. Oh, presumably the fittings are a little cheaper too as you don't need such a long length of pipe to reach the edge.

I think they're all fairly marginal gains though.

James

[Andy]

I went with the side drain, Easier to construct and you can slightly tip the tun to reduce deadspace.

[JamesF]

You mean in the wall of the pot, rather than near the edge of the base?

James

[kev93_10]

Forget dead space. Extraction is your concern.

Read How to brew by Palmer. While chapter on this.

K

[mooj]

I think central drain is better if you're fly sparging because of even draining but if you're batch sparging then it probably makes no difference. If you're happy to solder then you can avoid cutting up the bottom too much too - threaded fittings seem to involve a lot more cutting on the underside of the pot. I just cut a 60mm hole underside, 21mm q max for the inside central drain and a 15mm hole in the side, just pushing the 15mm pipe through the insulation. I have some pics somewhere if you want a visual idea.

[mooj]

I agree with not worrying about dead space on a mash tun, you can easily just add more liquor.

[GrowlingDogBeer]

I put a centre drain in mine, I had a false bottom.
At the time I converted mine we all had centre drain, not sure there is a good reason for it. If I was to convert another I would still bottom drain but put it near the edge.

[Monkeybrew]

Forget dead space. Extraction is your concern.

Read How to brew by Palmer. While chapter on this.

K

I learnt alot from that chapter when designing my cool box manifold, even extraction is your friend

Cheers

[brew like a dog]

I am yet to drill mine. I have put it off because i am concerned about my accuracy in cutting the the hole and subsequent leaking. Do you use a pilot hole before using the q max? is there a 'best way' of doing this? Its such a fantastic pot, i dont wish to end up with a leaking mash tun. Mine is going in the center and i have the stainless steel pipe work ready for it.

[JamesF]

The Q-Max needs a pilot hole for the bolt to go through. With the pots I think I started with a 5mm drill and then stepped up sizes to get the required diameter for the bolt. It's not such a major issue with something that can go under the drill press (I cut a 47mm hole in the lid of my boiler pot so I could pipe the steam outside). Where possible I also centre-punch the hole, but where that isn't possible a couple of layers of masking tape or insulting tape over the point to be drilled can help to stop the drill "wandering".

Something to act as a coolant whilst drilling can also be handy. I used cutting fluid I have for the lathe, but 3-in-1 or WD-40 or even a splash of paraffin would probably be ok for doing this particular job.

James

[GeeThom]

I had my thermopot for almost a year before I plucked up the courage to go near it with a drill. When I did it was quite simple using a pilot drill and a Q max cutter. These pots are usually quite thin so do not require a lot of drilling and it is helpful to let the drill do the work otherwise it hardens the steel, try to support it underneath if you can to prevent dents in the pot.
Once you have a pilot hole it is easy to widen it and the Q max literally takes seconds to cut through.

[barneey]

Dont forget a qmax cutter needs access to both sides of the piece of metal

[YeastFace Brew Co.]

Thanks for your comments.

I'm leaning to the offset drain I think, will mean less cutting of the underside and I should be able to get away with connecting to the Tao via an elbow and nipple rather than having to mess about with pipe.

I get to see the pots today, so will measure up for false bottom etc.

Last question (actually I highly doubt that). Do people bother with fitting a temp dial into a thermopot? The sunken ones look lovely, but if they hold the heat so well I could just check with a probe thermometer prior to sealing the lid?