The finished sparge arm


There are several things I have been wanting to do for a while to help dial in my system and to make brew days, simpler and easier. One of these brew DIY tasks was to make a sparge arm that was suitable for my DIY Thermos cool box Mash Tun. As the cool box is only 37.5 x 24.5 cm internal dimensions, most shop bought sparge arms wont fit.

I had some 15mm copper pipe left over from when I made the manifold for the bottom of the mash tun, Gav (HoppyBrewerUK) has a great video of how to do that.  So it was going to be a copper sparge arm as the pipe was going to be effectively free.



Centre punched corners and 2mm holes

I got a few bits and pieces from Screwfix, (see below for the shopping and cutting list), and started to cut pipe and assemble my first attempt. After trying it for size against the mash tun, I felt the long pipes were a bit close to the sides so cut them down and went for a narrower end design.

After carefully marking out the pipe for a hole every 2cm, I used a centre punch to make sure the drill was not going to wander when it came to drilling the holes. Then went round and drilled each of them. It is just as well I had decided to use 2mm instead of a smaller size as the chuck on my drill wouldn’t have gripped a smaller bit properly.

A little trick you can do with the centre punch is to give it hit on all the fitting joints as you can see in this picture, the resulting dip in the fitting will grip the pipe fairly securely so that it will hold together happily yet still be easy to pull apart if you want to give it a good clean .

Clips cut down to make removal easier


The only other thing that is not immediately obvious from the picture is that I cut down the white plastic pipe clips. This is because they clip the pipe very tightly if you use them without cutting them down, and as I want to be able to unclip the pipe fairly easily so it doesn’t rip screws out of the mounts.

I plan to test it out on Sunday when I brew and will update the post to let you know how it works, if I need to tweak it and how I decided to mount it, as currently I’m torn between just mounting it inside the lid, or on a couple of plastic rails to support it.



Parts list

Cutting list

  • About 1 metre of 15mm copper pipe
  • 4 x 15mm end feed 90 degree elbow
  • 1 x 15mm equal tee
  • 1 pack of plastic pipe clips
  • 1 x 30cm
  • 2 x 6cm
  • 2 x 14cm
  • Any length for your water feed




Sarah is an experienced home brewer, a qualified BJCP beer judge, organiser of the Welsh National Homebrew Competition and sometimes Brewtuber under her home brewery name, Daft Cat Brewing