Cheap & Easy 10 Gallon Rubbermaid MLT Conversion

I just finished building my MLT, thanks FlyGuy! It took three different hardware stores to find it all, but it's all done, and tighter than a gnat's ass. I ended up using hose clamps from work, the building guys use SS clamps and screws in solution, so I know the screws won't get all crappy.

Oh, and another way to get a clean cut on your braid: I cut the ends, then put in a small piece of copper tubing in the ends of the braid and used a handheld pipe cutter to cut a clean line.

Here's a question, though; how do you guys clean this after a mash? Do you actually disassemble the whole thing? Do you just remove the braid, then run hot water through it?


Pics of my beautiful new MLT:

It looks so.... erect....

I had a good lol moment at your observation. Yes, it does!

Has anyone converted on of these coolers to use as a MT? Opinions please.

https://cdn.homebrewtalk.com/gallery/data/1/cooler_image.JPG

Sorry Here's a pic.

Walmart has 5 Gallon Igloo's for $22, and in three colors! I'm thinking of picking one up this weekend along with a turkey fryer...they are only $37.

I found a source for stainless steel hose clamps AND screws. I haven't ordered them yet, but the price is right.

Marine grade all stainless steel hose clamps - PlumbingSupply.com

The 7/8" water heater braid works great. Plenty of flow and no floating as some experience with the smaller diameter braids. At the end of the line used the brass cap with a piece of the original vinyl tubing for a snug fit.

The difficult portion, other than finding the washers, was connecting to the barb. I used a small piece of the original vinyl tubing from inside the heater braid and another piece of a smaller OD vinyl tubing to bridge the gap. Then pierced thru the whole thing with stainless steel wire to hold it in place. No clamps necessary. Brewed on Saturday and everything stayed in place, no leaks. The temp dropped no more than 2F with a 60 minute mash.

Of course if you don't have stainless steel wire your line may slip off with vigorous stirring.

Thanks flyguy!!

ps. Used a little clear silicon to seal the wort from leaking in between the cooler layers and foam.

I just finished my second cooler conversion! The first was a 5-gallon, and the second was the 10-gallon that I snagged at HD. Like others have said, the 5-gallon is adequate for many AG batches, but with a grain bill over 9 lbs, you won't have room for a mash-out if you so desire. It looks like the 10-gallon will get most of the use, but it's nice to have both! Not a single drop of a leak so far with the 10-gallon. Initially, I had a few small drops leak out of the 5-gallon tun, but I just tweaked the tightness of the fittings and it stopped.

On a side note, this thread encouraged me to donate to the forum. Anyone on the fence about donating, just think how much money you have saved by threads such as this!

just finished my conversion tonight as well... (who didn't get the mlt conversion memo?)

i found a 42 quart coleman at KMART for 20.99. the spout on this one was a bit bigger, so i used 1/2 inch parts instead of the 3/8. looks good so far... no leaks!

i know it's some where in this crazy long thread... i can use the pvc tubing that was inside the stainless braid correct? i took it out, cut holes in the pvc and then pushed it back on.

thanks again to all for the great ideas.

My tun is pretty much complete too - however, I've got one small issue I'm wondering if others have hit: Even with my ball-valve assembly cinched down tight (not too tight!) the whole thing spins in the cooler hole - this happen to anyone else? How have you rectified this?

I'm using a rectangular Coleman Extreme cooler for which the drain hole is every-so-slightly larger than the 3/8th sized hardware which is probably the source of my issue, but I'm wondering how tightly the whole assemble fits in the round coolers or if there's some slipping there too?

Mine slipped, too, until I added the stainless steel washer on the inside of the cooler. It is now rock solid and never slips.

hmmm, mine is definitely not rock solid and I have the washer positioned as pictured in the post. My guess is slight differences in the hold opening in my cooler is the culprit. Using the o-ring between the cooler-seal and the stainless washer seems to create a water-tight seal (it leaked previously), but it's kind of a squishy fit, so opening and closing the ball-valve requires a little more care. At least it doesn't leak, I can brew - I'll have to work on a more solid solution. I will post pics if I figure out an elegant work-around since I know alot of guys are using the Coleman Extreme square coolers

Thanks again for you contribution to the homebrewing community flyguy - I've stepped into AG brewing much sooner than I would have because of the excellence of your post! I think everyone who used your post should send you a 6'er from the first batch we all brew from our new MLTs....well, maybe our 2nd or third batches when we've got the process figured out, lol

GimmeAles said:

hmmm, mine is definitely not rock solid and I have the washer positioned as pictured in the post. My guess is slight differences in the hold opening in my cooler is the culprit. Using the o-ring between the cooler-seal and the stainless washer seems to create a water-tight seal (it leaked previously), but it's kind of a squishy fit, so opening and closing the ball-valve requires a little more care. At least it doesn't leak, I can brew - I'll have to work on a more solid solution. I will post pics if I figure out an elegant work-around since I know alot of guys are using the Coleman Extreme square coolers

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Yes, that is certainly possible. One thing first -- have you tried tightening it up some more? If you go too far, it will likely start to leak, but I would be tempted to tighten it as much as it will allow and see if that helps (but you probably did this already). Otherwise, you might try adding a rubber washer between the exterior cooler wall and the fender washer. That might add enough resistance that it won't budge.

GimmeAles said:

Thanks again for you contribution to the homebrewing community flyguy - I've stepped into AG brewing much sooner than I would have because of the excellence of your post! I think everyone who used your post should send you a 6'er from the first batch we all brew from our new MLTs....well, maybe our 2nd or third batches when we've got the process figured out, lol

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I really appreciate the sentiment GA! Your heartfelt thanks alone is plenty of gratitude. (Besides, shipping beer to Canada will cost more than the whole MLT build!).

Cheers!

Good suggestion, I might try the extra washer on the outside. Actually, I'd thought about ordering a replacement valve from Coleman and using the perfectly fitted seal on the inside AND outside of the cooler wall, maybe negating one of the stainless washers and adding more rubber surface are for extra 'grip'.

It's true you are probably over 1k miles away even though we're right 'next' door . I will definitely drink you health from here on out for your input. Cheers!

I built one my MLT based on these designs last week and it worked Great! I made a copper pipe manifold instead of using a braid. It was a lot of work, but it turned out perfect. I brewed with it the next day and got ~80% mash efficiency! I'm stoked.

Thanks, FlyGuy!

BTW, my ball valve spins too. I may try adding a few O-rings here and there, but it doesn't leak a drop so I'm not too concerned.

My ball valve spins too. No leaks and added silicon to seal the foam core so there's nothing to worry about.

Mine spins too - well, would without extra washers (I used 5). O ring was an exercise in futility (Hole in cooler too big).

For clairity, I used the home depot 10 gallon cooler. Probably would have been better off doing a 1/2 inch conversion instead, but I'm happy with my conversion.

curtis97322 said:

Mine spins too - well, would without extra washers (I used 5). O ring was an exercise in futility (Hole in cooler too big).

For clairity, I used the home depot 10 gallon cooler. Probably would have been better off doing a 1/2 inch conversion instead, but I'm happy with my conversion.

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I am guessing you didn't use the method in this thread? What works really well with the 3/8" fittings is to re-use the original seal from around the cooler's plastic spigot. A 1/2" fitting is too large for this seal (unless you REALLY stretch it, which didn't work well for me).

What about bulk gasket material to make a new seal? They have it at the Ho-Dot in the sink reapir section for around $3 for a 10"x10" piece.

FlyGuy said:

Your heartfelt thanks alone is plenty of gratitude. (Besides, shipping beer to Canada will cost more than the whole MLT build!).

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I'm glad you feel that way, as I just finished my third cooler conversion! I don't want to think about the cost of shipping three six packs...

I used the method in the thread - and the original seal... But the opening in the cooler is pretty large - and the O ring isn't touching anything.

There are, however, NO LEAKS from my build...

And I am grateful for the parts list - without it I would have never gotten around to building a MLT

Interesting, I would have assumed that all the Rubbermaid 10 gal beverage coolers would have the same size opening. Regardless, the o-ring behind the outside washers is somewhat optional.

Glad to hear it is all holding water regardless!

We just made one, and it generally was easy and great. Just wanted to note some changes we made:

We used another barb at the internal end of the tube inside of the stainless supply hose so that we could screw the brass nut directly into it.

We couldn't find a stainless steel washer, so we used a thick gasket. It worked well. It was not completely water tight the first time we filled it, so I gave it one more full turn of tightness. Hopefully its water tight now because I doubt it will come apart again!

That's about it. Also a note: It creeks like crazy the first time it's filled with hot water!

Thanks for the great plans!

i have my 10 gal cooler and am going to buy parts today after work! hell yeah! one quick question though, any advantage/disadvantage to stainless valves and barbs?:rockin:

update: did some research on this site, and found enough info to choke a donkey on what i was looking for. maybe i should do that before i ask questions???

Thanks for the tutorial FlyGuy.

Interesting note. While getting help finding the parts at the local Home Depot the guy helping me said "what are you doing, brewing beer?".

I asked him if he brewed and he said, "no, but there have been a few people in here looking for the same parts".

You may interpret this as you wish. I take it to mean that your tutorial is the last word on a DIY MLT.

Dancing Banana.

My pleasure cytokine - glad you found the information helpful.

That's pretty cool that there have been enough people going into Home Depot for MLT parts that the sales guy actually remembers them! HBT should get a kickback!

Cheers

Hey guys. MLT has been working like a charm for a long time now. I was looking at the stainless steal braid and it was all twisted up. I had to cut off a couple of inches.

Is it a big deal if the the total length of braid is 9 inches? Is it going to affect my efficiency at all? The diameter of the cooler is 13.

Flyguy, thanks for the awesome post. I was in the local HB shop, they had a cooler almost exactly like what you setup. I was asking for a part's list, which they didn't have, and one customer in the shop pointed me to this DYI. I pulled it up on my phone's browser and went straight to Home Depot and picked up the parts. Got it all back home and it actually took longer to pick out the parts than put them all together.

Currently the MLT is sitting on the counter with 6gal of hot tap water in it and a clean paper towel under the spigot to check for leaks. Oh, I used 2 cut washers as spacer and after monkey-fisting the wrenches pretty hard the spigot doesn't spin and so far the paper towel is dry.

Thanks again, and like many others, w/o your write up I wouldn't have gotten around to doing it myself. Awesome work, mano.

first off, thanks flyguy, seems like it will work like a dream

however, i had to modify some setup to get a tight enough seal

i put 4 fender washers on the inside along with the spigot seal that came with the cooler. on the outside, 1 cut washer (a little thicker). it was the only way i could get the parts to tighten enough to seal the hole. also, put 2 o-rings on the outside so the outside washer could add pressure to seal

however, i'm getting a slight leak (i'll probably mash regardless) of about a tablespoon/hour. tried with only 1 o-ring on the outside and same results... i haven't applied the vinyl tape yet because i didn't want to finalize everything yet (and it doesn't appear that the leak is coming from any threads)...

just wondered if you had any thoughts.

I don't recommend using an Oring at all on the outside. All you're potentially doing is concealing a leak that will soak the insulation. Check out the weldless bulkhead design link in my sig for a discussion of why these may fail.

Irish1225 said:

i put 4 fender washers on the inside along with the spigot seal that came with the cooler. on the outside, 1 cut washer (a little thicker). it was the only way i could get the parts to tighten enough to seal the hole. also, put 2 o-rings on the outside so the outside washer could add pressure to seal

however, i'm getting a slight leak (i'll probably mash regardless) of about a tablespoon/hour. tried with only 1 o-ring on the outside and same results... i haven't applied the vinyl tape yet because i didn't want to finalize everything yet (and it doesn't appear that the leak is coming from any threads)...

just wondered if you had any thoughts.

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Chances are that your threads really are leaking. You pretty much need teflon tape on the outside parts, or liquid will make it through the threads eventually.

Another cause of leaking is actually over-tightening the parts. That seems to be pretty common. Have you tried backing off your tightness a bit?

I had no luck with the washers on the inside... couldn't get it to not leak. I put the OEM interior grommet back in the cooler and put just an o-ring between the fitting and the grommet and my leaks went away.

KerryD said:

I had no luck with the washers on the inside... couldn't get it to not leak. I put the OEM interior grommet back in the cooler and put just an o-ring between the fitting and the grommet and my leaks went away.

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I had the same experience. My build on this thread uses the same design.

Thanks to the OP, I was able to head out to Home Depot and Lowes today and assemble all the parts (except that annoying SS washer) needed to build a 5-gallon mash tun that I will be using to increase the amount of grain I use in my mini-mashes. The total cost (including some extra washers for the outside and a mini hacksaw) was about $55 up to this point - a bit more than I expected, but certainly much cheaper than had I bought a readily assembled one at a homebrew store.


Up to this point, I used an unmodified 2-gallon cooler. My boils max out at about 4 gallons, so I figure I can use up to 7 lbs of grain and still use a decent mash-to-grain and sparge-to-grain ratio.

So far no leaks, but the assembly is pretty loose, so I'll head out one more time trying to find the elusive SS washer tomorrow. If I can't find it locally, would anyone out there who has extras be willing to part with one or two if I pay for shipping?

EDIT: Also, are there any concerns about passivating the brass components that come into contact with the wort? Any concerns about exposing brass to StarSan, Oxyclean, PBW, etc?

ArcaneXor said:

So far no leaks, but the assembly is pretty loose, so I'll head out one more time trying to find the elusive SS washer tomorrow. If I can't find it locally, would anyone out there who has extras be willing to part with one or two if I pay for shipping?

EDIT: Also, are there any concerns about passivating the brass components that come into contact with the wort? Any concerns about exposing brass to StarSan, Oxyclean, PBW, etc?

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i actually found the illusive SS washers at a local ACE hardware. they were $1 a piece, but i guess that's what you pay to avoid shipping

for what its worth, home depot has these 10 gallon round coolers on sale right now for $37 USD.

Well, Ace didn't have the SS washer, so I ended up driving across town and picked up a 10-pack at Fastenal for $9. They weren't fender washers (just regular flat SS washers), but it works - No evidence of any leaking after 5 minutes filled with water, and I abused the cooler seal quite a bit from repeated assembly and disassembly to work out the most solid fit. Now I have parts to spare if I want to upgrade my 2-gallon tun.

I am basically using the same parts as in the OP, except a 16-inch, 3/8" braid, and one extra steel and one rubber washer on the outside of the cooler. The friction between the rubber washer and the cooler wall is the secret to keep the whole thing from rotating.

BTW, when I first read this thread the parts list sounded like it was written in a foreign language to me, and I managed to get the thing installed. If I could do it, so can anyone!

I am looking forward to making my first beer with this setup in a couple of weeks!

I just made this MLT today and thought I would throw in an idea I tried. Many are complaining of the hollow ss braiding collapsing after a few uses. I thought it might be because where it attaches to the nipple is about 1" or so off the bottom, then angles down. I figured a10+ pounds of grain sitting on top of that may crease it right at the end of the nipple and block off flow. I decided to use about 1 1/2" of the plastic hosing that comes inside this brading to give support to the tube right at the end until it reaches the bottom. I had to heat the plastic up with a lighter to stretch it onto the barb - but worked pretty good. Now, the tube is not hollow until it is at the bottom of the cooler and uses the small piece of inside tubing for support.

Also - I made mine in a circular formation instead of a straight piece inside by using a "T" and two barbed ends coming off that. A 30" piece of braided line works perfectly in this setup without getting too close to the edge. The extra support I spoke about above was a little harder to install in this formation - but I finally got it in place. I also added a 5/8" neoprene washer between the ss washer and stock gromet on the inside for extra sealing.

The Rubbermaid cooler was $37 at HD (with there name on it) and the fittings ended up costing me about $38 - seems the prices have gone up a tad since this thread started. Over all though it looks like it will work great and no leaks! Thanks all for the thread.

I just picked up a 10G Rubbermaid cooler this weekend to convert to an MLT. Without going through all 64 pages is the parts list on the front page still the master list? Any required adjustments.