The tank was very much like the one I used for my boiler build, only this time smaller at 68litres. I cut the top off and made a wooden hoop for the top, which was covered in foil tape on its upper surface. I then glued on the ring and lagged the tank's sides in five layers of closed cell sleeping mat (fewer around the handle though). The underside was covered in 25mm celotex much as in my boiler build.
Then to make it wipe-clean (and shiny
) I wrapped it in bubble/foil insulation from B&Q - this seems to be tougher than some I tried before and more immune to steam and water. I then fixed an aluminium strip around the top with stainless screws, partly to tie in the top of the silver stuff and partly to form a small lip or rim for the lid. i then ran food-grade silicone around the joins between the foil covered ring and the alu strip and tank walls:
The tank drains from the bottom and also has a radius where the walls meet the floor. So I was able to make quite a simple false bottom that sat on the radius and one central support (an M6 stainless bolt with washers and nuts fixing the bolt at the right height). The false bottom was perforated stainless with 2mm holes and some beer line cut open and wrapped around to stop scratching (I may need to add a handle in addition to the bolt sticking up):
Then the lid. This was a first for me; I've never routed aluminium before. I screwed an alu sheet to some plywood and routed a disc just big enough to fit the MT's rim. Then I made a spiral shaped sparge arm from some 10mm microbore I had left over from my IC - this just seemed like the simplest way to spread the sparging over the surface of the MT - and drilled around 40x 1mm diameter holes along the spiral. This was stepped up to 15mm and fitted into a street elbow soldered into the back of a tank connector that I'd drilled out to accept it.
I covered the top of the lid in 25mm of celotex insulation and added a 3/4"BSP thread to the tank connector - as thats the size I'm going to terminate all my flexible piping in, using 3/4" tap connectors with rubber O rings instead of fibre washers.
Then I added a valentine arm (I think its called, anyway) so that I can adjust the height of liquor during fly sparges of different quantities. The arm has 3/4" BSP female and male threads so that the same thread is presented for my flexible piping with or without the arm in place. The arm has a sideways step just after the female threads, so that the tap lever can be opened when the arm is vertical:
Finally, I covered the rim of the MT in cling film, ran some clear food grade silicone all around over the top of it, and squashed down the lid onto it. The idea being that it'll cast a silicone rubber seal around the lid, but being mostly enclosed in non-permiable materials its taking a long time to cure so no photos of that yet.
Finally, this ever-lasting upgrade looks like it could be nearing completion!
Cheers,
Kev
