Copper Grain Filter for Igloo Cooler Mash Tun

In my first post, I outlined the process of how to build an Igloo Cube Cooler Mash Tun, using stainless steel braid as a filter media. While the stainless braid works very well, you do have to be careful when stirring the mash not to damage the braid. Because of that, I decided to build a grain filter manifold out of copper tubing and this post explains what I did.

I went to Ace Hardware (Got a gift card from my father in law for Christmas!), and purchased the following items:

4 feet of Straight Copper Tubing (5/8 Ouside Diameter)
4 EPC 90 Degree Elbow (5/8 Inside Diameter)
3 EPC Copper Tee (5/8 Inside Diameter)

I took the straight copper tubing and I cut into the following pieces using a pipe cutter (could also use a hack saw):

2 @ 10 1/4 in
2 @ 4 3/4 in
4 @ 3 1/8 in
1 @ 2 in

The picture to the upper right shows how these pieces were placed to create the manifold.

The single 2 inch piece is going to be used to attach the filter manifold to the output valve. Since the valve is slightly higher than the cooler bottom, you will need to put a slight bend in it. I did this by taking a short piece of 3/8 steel rod and putting it in the bench vise. Then take the copper 2 inch piece of copper tube and place about an inch over the rod sticking out from the vise. Then take a longer piece of 3/8 steel rod and put in the remaining end of the 2 inch piece of copper, applying downward pressure to bend the copper. It's a good idea to go slow and test fit by putting one end of the piece in one of the copper tees and the other into the valve fitting, bending little by little. Once the tee sits on the cooler bottom, you've got the bend you need.

For each of the remaining straight pieces, I then used a small drill bit to drill multiple holes in each piece. It works well if you put a piece of scrap wood underneath so you can drill through straight through, creating 2 holes at once. Try to keep the number of holes uniform across each piece to create a balanced flow. Drill holes evenly until you get the drain flow you want by testing periodically. Any burrs on created on the outside of the copper due to drilling can be removed using a file. You can reference the assembled copper manifold (above left) to see the holes in the copper tubing. I didn't drill any holes in the elbows or tees but that could be done as well. If you plan on using the valve to regulate flow, you can drill many more holes in the manifold than I did.

Right is the finished copper manifold assembled and installed in the cooler mash/lauter tun. I didn't use any solder to sweat the pieces together, but found a good tap from a hammer on all of the ends and elbows creates a pretty tight fit. If needed, it also makes it possible to disassemble in the future for cleaning or storage. If you have questions regarding the installation of the ball valve, please reference the original post which includes detailed mash tun conversion instructions.