Cheap and Easy 10 gal Rubbermaid MLT Conversion

Building a mash & lauter tun from a large beverage container is easy and inexpensive to do.  You can buy Kewler Kit conversions that supply you with a pre-build bulkhead and faucet, but off-the-shelf components from your local hardware store work just as well, and cost far less.  I got all my parts at my local Home Depot.

The style of MLT that I built was for batch sparging.  To make it easy and cheap to build, I used a stainless steel braid for straining the grist during lautering.  But one could easily substitute a false bottom or manifold, if desired.  The bulkhead is made from a brass nipple connector and a few washers to add rigidity and obtain the correct spacing.  The faucet is a simple ball valve.  That's it!

(Click on any picture to enlarge it.)

Parts List:

Here are the parts you will need for the conversion (see picture, left to right):

•  Rubbermaid 10 gallon round beverage cooler
•  all stainless steel ¼” hose clamps x 2
•  brass square head plug (Watts A-737)
•  ½” x 12” (or larger) braided stainless steel supply hose
•  3/8” female barb adapter (Watts A-298)
•  5/8” stainless steel fender washer
•  3/8” MIP x 1-1/2” brass nipple (Watts A-786)
•  seal from plastic spigot of cooler (shown below)
•  Teflon tape (note: everything to the left of the tape in the picture above goes inside the cooler, and everything to the right goes outside)
•  5/8” O-ring (preferably heat resistant, if you can find one)
•  3 x 5/8” fender washers
•  3/8” threaded ball valve
•  3/8” male barb adapter (Watts A-294)

Assembly

Step 1 - Remove the spigot from the cooler:

• using a wrench to firmly hold the nut inside the cooler, remove the plastic spigot from the Rubbermaid cooler
• retain the seal from the inside of the cooler for use in Step 2 below

Step 2 - Inside parts:

•  Stainless steel braid:
  • cut the ends off the stainless steel braided supply hose using a hacksaw or rotary tool (my Dremel tool cut through the braid like nothing -- took about 60 seconds)
  • using a set of needle nose pliers, grab the flexible hose inside the braid, and PUSH the braid off the hose (don't pull!)
  • insert the brass square head plug into one end of the braid and secure with a hose clamp (or you can just crimp down the end, but then the braid may float up in your mash)

•  Bulkhead:
  • apply a few wraps of teflon tape to threads on the brass nipple
  • slide stainless steel washer onto brass nipple
  • securely attach female barb adapter to brass nipple
  • insert seal from plastic spigot on inside of cooler and insert brass nipple inside

Step 3 - Outside Parts:

•  pull brass nipple all the way through the hole in the cooler, and insert O-ring

•  apply teflon tape to threads on nipple
•  add fender washers as spacers to ensure a tight fit of the components once the ball valve is attached (mine needed 3 washers)
•  attach the ball valve
•  apply teflon tape to the male barb connector, and attach it to the bal valve

Step 4 - Attach Stainless Steel Braid

•  slip a SS hose clamp over the open end of the SS braid
• slide the braid onto the barb connector inside the cooler, and tighten the hose clamp

The Finished Product

That's it. You now have a cheap MLT that was easy to put together.  To be sure mine didn't leak, I filled it to the 10 gallon capacity with water, and let it sit for 45 minutes.  Didn't leak a drop!