Yet another thermo pot conversion

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schlafsack

Yet another thermo pot conversion

Post by schlafsack » Sun Jan 11, 2015 10:32 pm

Hello. I bought three 80L thermo pots last year with the intention of converting them into a HLT, mash tun and boiler. Unfortunately life got in the way and I've only just got round to starting. Now that the pots are available again in the UK and there was some interest in the elbow I found, I thought I'd post a few pictures as I go.

Most of what I'm attempting to do has been worked out by others, such as barneey, I'm very much standing on the shoulders of giants and appreciate the hard work they have put into figuring all this out.

I started on the HLT today, which has a pair of bottom drains and a pair of 3kw burco elements:

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This pot has 3.5cm between the skin and the inner wall, I was hoping that I would be able to use the square elbow and some of Mr. Lards pre-cut deck fittings without any modification, alas they are about 1cm too big. I'm going to have to cut the deck fitting down and use a slimmer nut and seal:

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What are my best options for cutting the deck fitting down? I read somewhere that you can use two nuts as a guide for a jigsaw blade, and then remove the nuts to tidy up the threads....

I've also managed to damage a pair of the square elbows. I couldn't screw a barrel more than a few turns into one, so I screwed in the second elbow and used some pipe for leverage. It wouldn't go any further in and proved very difficult to get out, turns out there was some swarf left over which has trashed the male thread of one elbow and the female thread of the other. If anybody else uses these parts make sure you check the insides thoroughly.

schlafsack

Re: Yet another thermo pot conversion

Post by schlafsack » Sun Jan 11, 2015 10:50 pm

For the boiler I'm going to try something slightly different. I've got two of MrLards lwd elements, and I've found a tri-clamp fitting that screws to the thread:

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I'm going to use tri-clamp fittings, through the pot walls, so that the elements are easily removed. Hopefully I can then use a false bottom as a hop filter and take the elements out for cleaning:

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barneey
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Re: Yet another thermo pot conversion

Post by barneey » Mon Jan 12, 2015 12:17 am

The easiest way to cut down a deck fitting is to grind it down.

I use a bench mounted sander (with ceramic belt) for the job, I have no idea where MrL got his deck fittings from but it was always a lottery (if bought from ASAP) if they were threaded all the way to the rim.

If you have access to a suitable bench sander you could always reduce the thickness of the nut as well, easy enough job with the right tools.

For cutting stainless items (if you go down that route) BUY a stainless cutting blade for a standard angle grinder (they are very thin). DONT cut with a standard metal blade.

When cutting the holes for the cable exit, size them to allow a cable gland screw fit.

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Re: Yet another thermo pot conversion

Post by Fil » Mon Jan 12, 2015 12:45 am

Interesting take on the build. Why the double drain on the hlt? I can only think its for a dedicated feed to a pump/recirc? or have you more cunning plans?

i assume your going for external chilling with an insulated kettle ;)

2 x 3kw elements may be overkill in an insulated kettle, and perhaps you may benefit from some power controllers, especially if a single 3kw creates to violent a boil, the hlt should heat up superfast tho ;)

for the chopping down of skin fittings chop off all but 4-5mm with an angle grinder or perhaps a jigsaw with a suitable blade? an angle grinder with a 1mm SS cutting disc (99p) will cut through easily. If your confident with your eye and hand coordination perhaps take off more.. fwiw my only chop with an angle grinder was not square at all.

a belt sander is the tool to grind down the last few mm.. im lucky i have one mounted on the bench, to use it i needed heat proof gloves and its not a quick job, (nasty black dust too)

with a hand sander you could hold the skin fitting in a jig or vice ;)

have you considered using the elbow with a M20 washer without a nut to make the seal, pack with more m20 washers if needed.. ??


to test the depth and progress as you go you will need a small file and perhaps a nut and spanner to open up the start of the thread after a grinding/cutting.

i can dig out a pic of my ground down fitting if useful, iirc it was about 3 threads left on it when finished.

if you dont have the tools and feel a lil cheeky, argos will accept tools you dont actually need as returns within 21 days ;). or if close to another brewbuilder a quick loan of facilities may be arranged ..

with a good pinch i found all i needed to make a seal when fitting was a light smear of lsx silicone thread sealer on the skin fitting flange rear and tighten.

for fitting the elements with triclamps (nice touch!) i think you will have problems finding a suitable fitting to make a threaded seal with the pot, you could however consider soldering a ferrule to the pot, its actually a very easy solder job easier than a 22mm copper pipe solder even.. with a good acid flux and clean metal loop solder around both inside and outside of the fitting and then simply apply heat to the triclamp fitting flange. being more substantial metal than the thin skinned pot it will soak up the heat and when its at solder melting temp so will the thin skin touching it too ;) job done..
i put a 2" triclamp flange on a 98l pot lid this way, once soldered i used a 38.5mm qmax to punch out the centre...

Hope you enjoy a trouble free build, keep the pics n info comming..
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

schlafsack

Re: Yet another thermo pot conversion

Post by schlafsack » Mon Jan 12, 2015 1:17 am

Thanks for the replys guys. Yes, I'm going to have a dedicated recirculation loop, hence the second bottom drain.

For the boiler I'm going to try the new auber pwm controller. My brother goes to the states quite regularly and one is on its way via San Fran as we speak.

Thanks for the tips on the thread cutting, I'll see if I can borrow a grinder for a couple of days.

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Re: Yet another thermo pot conversion

Post by ciderhead » Mon Jan 12, 2015 1:04 pm

You can never see enough posts about thermopot conversions and the different ways folks configure their pots, thanks for posting =D>

schlafsack

Re: Yet another thermo pot conversion

Post by schlafsack » Mon Jan 12, 2015 3:08 pm

I did some work on a herms pot last year, it's finished but untested. I used a small thermo pot and a coil from MrLard. Finding the right sized compression fittings for the coil was tricky and I'm concerned that I wont get a good flow rate through the coil. We shall see.

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Yet another thermo pot conversion

Post by ciderhead » Mon Jan 12, 2015 7:29 pm

Can you show a pic of your element? I just bought a 6l and am debating with myself about bottom or side wall elements, I am guessing side walls would be close to impossible to seal because of the curvature of the pot?
My coil from Mr lard is great at 11l/min with a chugger but it doesn't have that many turns!, I also found that I needed full bore disconnects on the feed to the pump and standard or narrower on outflow. Including pushback from the coil means I don't need to restrict the outflow with a valve.

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Re: Yet another thermo pot conversion

Post by Jocky » Tue Jan 13, 2015 10:07 am

How long are the 3kw LWD elements?

Good pictures and info here. Definitely keen to get a HERMS pot one day.
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Re: Yet another thermo pot conversion

Post by Fil » Tue Jan 13, 2015 12:19 pm

Jocky wrote:How long are the 3kw LWD elements?

Good pictures and info here. Definitely keen to get a HERMS pot one day.

Circa 35cm into the pot... 2 x in a 70-98l stockpot will cross in the centre..
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

schlafsack

Re: Yet another thermo pot conversion

Post by schlafsack » Thu Jan 15, 2015 9:56 pm

Based in on the principle of keeping it simple and using tools I have, I decided to try and use my jigsaw to cut down my deck fittings. I got some inox blades, used the nuts as a blade guide and a way of locking the fitting into a vice:

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I used plenty of oil ant it took two blades to get through. I finished it off with a hacksaw, which seemed to cut the steel better than the jigsaw, to such an extent that I'd consider using a hacksaw for the whole cut next time.

I used a file to finish off the surface and remove the sharp edges:

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I then removed the nut to clean up the threads, followed by a little filing to removed the swarf:

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The cut down deck drain screwed into the elbow like butter, giving a total height of about 2.75 cm:

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schlafsack

Re: Yet another thermo pot conversion

Post by schlafsack » Thu Jan 15, 2015 10:04 pm

Ciderhead, I've used a burco element in my herms pot, so it's a bottom fitting. It *just* fits, and you have to be careful drilling the hole as the element is slightly off-centre:

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Yet another thermo pot conversion

Post by ciderhead » Thu Jan 15, 2015 11:56 pm

Cheers for that I have one of those elements on order from Amazon, that's the 6l version yeah? I see what you mean about the drilling, I think I'll pop it in upside down, mark with a pencil and then go for it. Are you happy it's not too close to the edge and there aren't hot spots?
I know it stands off the floor so it should be ok on that front

schlafsack

Re: Yet another thermo pot conversion

Post by schlafsack » Sun Jan 18, 2015 1:11 am

Finished off the second deck drain today:

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...and started to fit the elements and the drains to the pot:

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After a quick soak test it's seems there is a leak. I've noticed that I've over tightened one of the element lock nuts and the washer has deformed. I've also over tightened one of the ball valves which has pulled one of the drains out of place.

Anybody know how to clean up furnox ls-x?

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Re: Yet another thermo pot conversion

Post by barneey » Mon Jan 19, 2015 11:55 am

Lsx should normally just rub off but IIRC a solvent such as white or meths might shift it also.

The last few tweaks regarding things moving is standard with these builds so nothing to worry about there.

Finally have a look through ebay at the laser cut disk (offcut pieces) either been cut wrong or have lead in marks, they make great covers for the holes, silicone in place for easy removal if needed. http://www.ebay.co.uk/sch/profilemen/m. ... 7675.l2562
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Hops, cider pips & hello.

Name the Movie + song :)

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