Cheap & Easy 10 Gallon Rubbermaid MLT Conversion

[FlyGuy]

You can buy Kewler Kit conversions that supply you with a pre-build bulkhead and faucet for converting a 10 gallon Rubbermaid beverage cooler into a mash & lauter tun. 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 for a fraction of the cost of a Kewler conversion kit, or other commercial products.

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 (sometimes hard to find, but try Fastenal or read this thread if you are stuck)
- 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)

 

[FlyGuy]

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

 

[FlyGuy]

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

 

[FlyGuy]

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

EDIT: The hose clamps didn't work. See my update here: https://www.homebrewtalk.com/showpost.php?p=253344&postcount=62

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!

For additional details and some higher res photos, go to:
http://members.shaw.ca/Fly_Guy/mlt.htm

 

[Sir Humpsalot]

AWESOME!!!!!!!

What was the total bill?

 

[FlyGuy]

AWESOME!!!!!!!

What was the total bill?

Well, these are Canadian dollars, but here goes:

- Rubbermaid 10 gallon round beverage cooler - $34.99
- all stainless steel ¼” hose clamps x 2 - $0.66/ea
- brass square head plug (Watts A-737) - $1.09
- ½” x 12” (or larger) braided stainless steel supply hose - $4.99
- 3/8” female barb adapter (Watts A-298) - $1.72
- 5/8” stainless steel fender washer - $0.39
- 3/8” MIP x 1-1/2” brass nipple (Watts A-786) - $1.49
- 5/8” O-ring (preferably heat resistant, if you can find one) - $0.59
- 3 x 5/8” fender washers - $.29/ea
- 3/8” threaded ball valve - $6.89
- 3/8” male barb adapter (Watts A-294) - $1.89

Total cost: $56.23 CDN, which is about $8 USD.

No seriously, it would be about $46 US.

If you buy something similar from places like morebeer.com, it would be over $100. It took all of about 5 minutes to assemble everything (although I did do a few trips to Home Depot to find the parts to make it all work).

 

[Orfy]

Can I use this for the Wiki or do you want to add it?

https://www.homebrewtalk.com/wiki/index.php/Converting_a_cooler_to_a_mash_tun

 

[FlyGuy]

Can I use this for the Wiki or do you want to add it?

https://www.homebrewtalk.com/wiki/index.php/Converting_a_cooler_to_a_mash_tun

Sure, add away. I'm not a wiki kinda guy.

 

[Orfy]

Thanks.

https://www.homebrewtalk.com/wiki/index.php/Converting_a_cooler_to_a_mash_tun

If you add it to your signature it'll help others.

Cheers.

 

[Tony]

Great posting FlyGuy!!! And good job on the mash tun!

 

[FlyGuy]

Thanks.

https://www.homebrewtalk.com/wiki/index.php/Converting_a_cooler_to_a_mash_tun

If you add it to your signature it'll help others.

Cheers.

Good suggestion - done!

 

[Toilet Rocker]

Nicely done. And great step-by-step instructions there.

 

[ripley]

Great post, I've been looking into going AG and this just made it easier. Going to Lowes today hopefully they have everything

 

[ColoradoXJ13]

where is the best place to get one of these coolers at a good price?

 

[Brewnurse]

where is the best place to get one of these coolers at a good price?

I have been looking around this week and the 10 gallons are a little hard to find. Most of the stores, at least here in California, have the 5 gallon coolers. The 5 gallons go for $23-45. But, I found a roofing company in AZ that has the 10 gallons for $45, I think. I got two shipped for $110. Most stores sell the 10 gallons for $75-89. Best bet is to look around, check e-bay and craigs list you may get luckky. Hope that helps.

 

[GoatFarmersInternational]

Thank you FlyGuy, for this excellent post. The parts list is really helpful; I just finished putting mine together (I couldn't find a 5/8" stainless fender washer for the inside, but I found some wierd metric washer that was close to 5/8 and it ended up working fine).
So if everything goes well, I should be doing my first AG batch before the end of next week (waiting for a turkey fryer to come in the mail).

Regarding the 10 gal coolers, I got mine from Ace Hardware for just under $50, but I did notice that this place http://cspoutdoors.stores.yahoo.net/10galwatcool.html is selling them for $41.95 (not including shipping).

 

[ColoradoXJ13]

Well, that was easy, I went to work today, came home, went for a 5 mile run with the dog, and when I get back, I have a text message from the guy that I do about 1/2 of my brew sessions with saying "We now have a MLT", I had sent him this link a couple days ago and he said he was bored today and went to Home Depot...

As a side note, he said the water cooler was only $40....not bad at all.

 

[skifast1]

FWIW, others have recommended putting a short length of tubing over the inner barb to let the hose clamp get a better grip over the stainless weave. I did this on my 2-gal MLT and it seemed to really get a good bite.

 

[The Pol]

I purchased my 10 gallon coolers at Ace, they were $49 with free shipping to the store. Total was $106 for (2) of them

 

[uuurang]

Great post! Ordered one at Ace hardware. $47. will pick up tomorrow. Picked up all parts for bulk head at homedepot. Great description of parts. found them all except for the stainless 5/8 washers. only had zinc coated. found them at menards. Awesome! Thanks!

Also, this will be 1st AG when up and running, do I need to be concerned about grain depth on smaller beers under 1.065 with this 10 gal. cooler? IIRC, john palmer said ideal depth is 12 in. Please correct if wrong! Thanks!

 

[skifast1]

...found them all except for the stainless 5/8 washers.

My math may be off, but I think i've seen other posters say they've found 16mm SS washers that are a close fit.

 

[The Pol]

Purchased an 18x36x72" industrial shelving unit from Lowes today for $60 to use as a sculpture for my new 10 gallon tuns and my brewpot... it looks awesome, sorry now pics. Each shelf is rated for 1,000 lbs, not a problem! Pics coming?!

Pol

 

[uuurang]

My math may be off, but I think i've seen other posters say they've found 16mm SS washers that are a close fit.

That didn't occur to me...when standard fails, go metric! It's good enough for the rest of the world. thanks!

 

[RoaringBrewer]

Awesome. Just the inspiration I needed to get me into mini-mash or start on some AG...

 

[uuurang]

Well, I hate to poo-poo this, but finding 5/8 ss washer is a tough call at stores in my area. The largest I've been able to find are 1/2 in ss washers. Home Despot, no dice, True Value hardware, nope, Ace hardware, nada. And as far as the metric goes nobody carries stainless metric washers. Asked at each one.

Would a steel washer be good enough? I can find regular steel washers in the 5/8 in. size no prob. Will they rust? Ahh, humbug, I'll just give it a try and see what happens.

Just sharing my experience.

 

[JnJ]

Well, I hate to poo-poo this, but finding 5/8 ss washer is a tough call at stores in my area. The largest I've been able to find are 1/2 in ss washers. Home Despot, no dice, True Value hardware, nope, Ace hardware, nada. And as far as the metric goes nobody carries stainless metric washers. Asked at each one.

Would a steel washer be good enough? I can find regular steel washers in the 5/8 in. size no prob. Will they rust? Ahh, humbug, I'll just give it a try and see what happens.

Just sharing my experience.

No stainless here either. I found zinc plated, anyone have any idea if it will work?

 

[uuurang]

found a stainless 5/8 washer at Menards in wi. So, there out there. Just not easy to find.

 

[FlyGuy]

No stainless here either. I found zinc plated, anyone have any idea if it will work?

No, you don't want to use any plated washers. It can lead to off flavours in the beer. I got frustrated looking for them too, trying a few stores, but as it turned out, the original store I bought everything else at (Home Depot) had them. I just didn't look hard enough.

If you can't find stainless steel, try nylon washers, or even brass washers. Those might be available.

 

[shlap]

Looks a lot easier than the cooler w/copper pipe MT that I just finished building. I get about 76% efficiency with it. What efficiency can you get with this sort of MT?

 

[FlyGuy]

Looks a lot easier than the cooler w/copper pipe MT that I just finished building. I get about 76% efficiency with it. What efficiency can you get with this sort of MT?

Yes, the SS braid is the essence of simplicity (and it is cheap). But if you fly sparge, this setup is not for you (you probably won't get 76% efficiency). If you batch sparge, 76% efficiency is acheivable, based on the experience of others.

 

[uuurang]

Yo, flyguy, Thanks for the great idea on this mash tun. I assembled and built one myself. Haven't used it yet. Too much snow out back and the wife doesn't care for brewing indoors.

Of all the DIY mash tuns i've seen on the net yours has to be among the best. The parts list is complete and consistent. The Watts part #'s are great. The toughest part was locating a 10 gal. cooler, and locating stainless washers. I suppoose using a rectangular cooler would be cheaper and easier to find. I wonder if this setup would work as well on a 5 gal. cooler (much easier to find, imo)?

 

[uuurang]

Also,

What's your opinion on placing a 4-way brass junction halfway up stainless mesh screen and splitting another mesh screen perpindicular to original so as to increase mash efficiency? Probably wouldn't be worh the effort

TIA!

 

[The Pol]

Here is my new 10 gallon setup, with my 3 tier system. I cannot wait to fire this thing up!!! It is obviously the 3 tier system with the orange coolers on it... Through the wall therms are coming, waiting for parts to arrive.

http://s168.photobucket.com/albums/u189/PolTavern/

Pol

 

[kladue]

If you want more coverage on the bottom, use a tee where the plug is and bring two braid arms back toward the outlet. You could use some bare #14 copper wire to hold the arms halfway between side and center braid or pull the arms together in the center for an X pattern for better coverage.

 

[skifast1]

I wonder if this setup would work as well on a 5 gal. cooler (much easier to find, imo)?

FWIW, it definitely works on a 2-gal Rubbermaid round cooler. I did this with the exact same hardware a few weeks ago. Stands to reason the 5-gal would be the same dimensions as well.

 

[FlyGuy]

Also,

What's your opinion on placing a 4-way brass junction halfway up stainless mesh screen and splitting another mesh screen perpindicular to original so as to increase mash efficiency? Probably wouldn't be worh the effort

TIA!

I am sure this would work, but if you are going to go to the effort and expense, you might be better off building a CPVC manifold instead. It would work very well for both batch sparging and even fly sparging.

Another option is to use a 3-way connector (i.e. a T-connector) and use a longer braid that forms a loop in the cooler. I am sure that would be just as good as anything, and be really easy to build, too. Cheers!

 

[FlyGuy]

Here is my new 10 gallon setup, with my 3 tier system. I cannot wait to fire this thing up!!! It is obviously the 3 tier system with the orange coolers on it... Through the wall therms are coming, waiting for parts to arrive.

http://s168.photobucket.com/albums/u189/PolTavern/

Pol

Very nice! Let us know how it works out for you. I will be especially interested since I will be using a similar setup -- I just won't have time to try it out myself for a while.

 

[skifast1]

FYI - I got tired of scouring the local hardware stores for 5/8" stainless washers for my in-progress MLT's so I just got a bulk order online. If anyone wants some, i'll mail 'em to you for a buck apiece, postage included. Drop me a PM if you're interested.

Edit - all sold out, sorry!

 

[TUCK]

Wow thanks for the detailed tutorial.

Nice Job!

 

[skifast1]

Yee-hah, count me as another member of the 10-gal Rubbermaid MLT club

Next up on the road to AG: A big honkin-pot!