One for the engineersI don't think this isn't really going to be of any use or interest to any of the home breweer on here but it might be to one or two of the engineers as it's a purely accidental yet fantastic solutuion to making a great bit of brewingk kit.
In beer making you need to spray hot water evenly over the bed of grain, it's called sparging. One good way is to use a rotation sparge arm, which is effectively an upside down garden sprinkler. You can buy them for 30 quid but in playing around the other night I managed to knock up a really efficient one for less than a fiver - the key is to have a rotating pivot that doesn't leak.
I've just lifted my original post straight from a brewing forum:
| saw some plans online for making a sparge arm and whilst tinkering with those, I kind of stumbled onto quite a straight forward drip free pivot for a sparge arm. All the materials used are brass tubing from a modelling shop, approx £1 per length (either 30cm or 50cm)
1 off 1/4"
1 off 7/32"
1 off 3/16"
Each tube fits quite snugly within the next
The key to the arm working is to us a pipe cutter rather than a hacksaw as you need the bevelled finish that the cutter puts on the tube.
Cut a length of each approx lengths are (left to right) 3/16" 10cm, 7/32" 5cm and 1/4" 8cm - the 3/16" is longer in the phot but I trimmed it down to suit my mash tun.
Each tube needs to have one end which is straight and the other end needs to have the bevelled restriction caused by the pipe cutter. You then need to splay the straight end of the 3/16" tube so that it won't pass through the the 7/32" tube
Here are the straight ends and the slightly splayed 3/16" end
Here's what I mean by the bevel or restriction caused by the pipe cutter
Fit them together, one inside the other
Let them drop through each other so you will end up only seeing the 1/4" and 3/16" tubes - the 7/32" is hidden inside. Now the two smaller tubes both move freely inside the larger tube. You may need to do a bit of fettling/filing etc but you can get a very free running pivot.
take the remaining 25cm of the 7/32" tube - this will become the sparge arm. Mark the centre and drill it on one side only to accept the 3/16" tube
Solder it at right anngles, this is my 2nd attempt as I flooded the inside of the pipe with solder, for this one I use a tent peg as an insert to stop the solder preventing water flow. Then drill the opposing sides to cause the spinning action.
I've not found anything in my garage suitable to bung the ends up with yet, so for now I stuffed a rolled up ball of ptfe into each end so I could trial it. Initial tests have it working really well with relatively little head required. And there's not a drop coming from the pivot.