There's been some debate recently as to the types of elements to use, and I'm not wanting to start a parallel debate here. But after trying the jugs elements and backer-type kettle elements in the past my own personal preference these days is for immersion heaters, and so thats what I used. But my tank is a thick stainless jobby, so fitting was going to be interesting - I'd considered soft soldering it in this thread but been put off by the cost and difficulty of getting the flux. Welding would probably have been best, but I don't have the kit to weld stainless and wanted to do it myself. So, I decided to go with a mechanical approach - this doesn't harm the tank (aside from the hole thats needed anyway) so a stainless flange could always be welded on at a later date if I wanted.
First off I hammered a flat-ish area in the tank with a lump hammer and some sacrificial wood to prevent denting the surface - the wall is over 2mm thick and made quite a noise even though I was sitting on it at the time. I then cut a 64mm hole in it with a cobalt holesaw then spent a bit of time prying out/knocking in any small undulations in the flatness around the hole's rim. Initially I tried to use a 2 1/4" flange as a back nut, but it soon became clear that wasn't going to work - no way I could get enough leverage on it to seal against imperfectly flat walls that thick. So I got a mechanical flange instead and opened out the hole to the required 65mm with a half round file:
And here is the mechanical flange fitted - it needed some very large grips to seal properly:
And here is the 11" immersion fitted - its 3kw at 240v or 2.7kw at 230v. I also put the tap on (a 3/4" stainless fleabay bargain) so that I could test the seal:
The key issue of this flange over a welded/soldered one is that it has an internal part to it, which doesn't let all immersion elements fit due to the way they're bent over in a largish radius at the end, and which would make cleaning harder. I got over this by trying elements at a local plumbing retailer, and I squeezed some LS-X in behind it and around the threads before tightening the flange - which I had to do quite quickly as this seems to cure faster than normal silicone:
Next up was insulation - and as I'm hoping for a rolling boil in up to 25 gallons with one element this had to be good. I'd initially decided on armaflex, although the cost was a little hair-raising, a 1" mat has got a thermal resistance equivalent to several inches of rockwool though. However, I'd discovered that good quality closed-cell sleeping mats were similar in performance but were also not cheap so it seemed I may as well go for armaflex. Then I found that go outdoors had a two-for £8 in store offer on these mats - I couldn't find any thermal ratings but they seemed to be the same material as the expensive ones I'd seen which had the decent thermal ratings, and they did at least claim 'very high' thermal performance. When I discovered that the armaflex only came in awkward/inefficient sizes for my needs I decided to risk the mats. I decided to go for 24mm, or three layers, which took five mats in total (though I reduced it to one layer around the handle and left a 20mm gap around the element - didn't want anything overheating/melting):
I had purposely not cut the top off the tank so that it could be insulated almost all around, and I've also got plans for making a steam extraction pipe so leaving the top on would mean I didn't need to make a hood. This left a 6" hole so i may regret it when it comes to emptying hops/trub, but at least I can reach the bottom through it so it seemed worth a try. I insulated the top in the same way as the sides, and covered everything with that radiator foil bubble wrap stuff to make it wipe-clean (and shiny
). Mostly this was an old roll from wickes that I had left over but I had to buy some more for the top, and the foil on this was thinner, so i may have to cover it in more foil tape to make it more robust.Edit: Not only was the newer roll's foil thinner, but it also lost its shine after contact with steam/water and looked patchy and messy; the old foil roll used on the sides was much superior. So I am going to have to cover the top with more foil tape as I thought:
The brass doofa on top is a 3/4" male thread for my inlet; I've caused so many floods by loose pipes flopping out that I decided to put proper connectors on. I also decided to standardise my pipe fittings for the same size everywhere, and settled on 3/4" when I found how long it takes to drain 25 gallons through 15mm. I'm going to have a silicone hose dip tube inside this inlet to stop too much foaming when filling.
That left the underneath. Fortunately the tank sits on a rim (the base is angled down towards the outlet), so I could just fill this. I had some 1" celotex/kingspan type foam left over so friction fit that in the recess, and taped around the edge with more foil tape. Its maybe not the most robust approach having the tape over the ring it sits on, but the tank is so heavy I'm not intending to routinely move it about - think I may need a wet and dry vacuum cleaner or something to suck out the hops..
EDIT: Plan B - the foil tape wasn't robust enough for the tank to sit on; sliding/positioning the tank tore it. So I just taped the celotex to the inside if the bottom rim, rather than taping completely over it.
Then for the hop-stopper. As its quite a big tank I decided on a bigger one than I've used before, so went with the stainless braid from a 900mm hose - it says not for drinking water but I think that refers to the rubber inside that I discarded - can't see that it would be the stainless braid anyway. After having plated hose clips rust on me before, I used some stainless ones this time. By luck, I discovered that a bit of silicone tube I had fitted snugly in the outlet pipe, so I used that to connect the hop stopper:
So thats it. Annoyingly whilst I did get some hot condition flex I didn't get a plug as I assumed I already had one, typically though none of the ones I have look up to much and this isn't the right application for that sort of thing. Being bank hols I'm going to have to wait now before I can test it. I already have a HLT made from a hot water cylinder (which I may now lag with the same foil roll just for aesthetics) so next it'll be the MT - I have a smaller tank ready for that and yet more sleeping mats, but currently am waiting for my perforated stainless to arrive for its false bottom.
Cheers
Kev
, only thing i would worry about is getting hops out and cleaning it out after the boil,I myself looked at using the same type of 3kw element but was worried that my shed brew-house electrics would blow fuses hope yours are up to it.