The No-Leak MLT bulkhead design

[Bobby_M]

When given the option of welding, I'd always recommend it over weldless. It's just that if you have to go weldless, some designs are better than others in my humble opinion.

 

[alexnphillips]

I was just working last night on setting up the rev 3 MLT. This one and the last one will both be Coleman Xtreame's. The spigot that comes on this cooler unscrews leaving you with a threaded piece, a "nut", and a white piece that held it all in place. This white piece is what is actually up against the cooler wall and goes inside wall. It goes about half way through the wall and is probably an inch around against the wall. The 1/2 inch nipple fits perfectly through it. Since this is now my second Xtreame cooler I now have one on the inside and outside. If you only had the one you should probably just put it on the inside. Works perfectly.

Does this make any since?

 

[Ace_Club]

Would it be of benefit to apply some super glue or silicone caulk to the insulation portion of the cooler prior to inserting the 3/4" PVC reinforcement?

I see this as sort of waterproofing the interior of the cooler such that if the design did leak, there would be no wort seeping into the insulation of the cooler. Thoughts?

 

[-TH-]

Would it be of benefit to apply some super glue or silicone caulk to the insulation portion of the cooler prior to inserting the 3/4" PVC reinforcement?

I see this as sort of waterproofing the interior of the cooler such that if the design did leak, there would be no wort seeping into the insulation of the cooler. Thoughts?

Yes I did exactly that. I used cpvc cement.

 

[JediJoel]

Bobby, picture dissappeared from here too...

 

[Bobby_M]

Thanks for the heads up. I had all the pics back up but some of them have ".jpg" in capital letters and that was messing up the links. Weird.

 

[-TH-]

This has probably come up before but what about this variation:

Then you wouldn't have to worry about the threads in the nipple because the liquid would never come in contact with the nipple at all (well except for the interior surface of course). I wonder if this would seal better because any leakage would have to seep through a directly clamped surface, unlike the OP diagram where you are blocking leakage that would flow perp to clamping surface, ie along the outer surface of the nipple "under" the o ring.

Not that I've heard of any problems with the orig design but I was just wondering...

 

[Cpt_Kirks]

Thanks for the heads up. I had all the pics back up but some of them have ".jpg" in capital letters and that was messing up the links. Weird.

UNIX server, maybe. UNIX is case sensitive.

 

[Bobby_M]

This has probably come up before but what about this variation:

Then you wouldn't have to worry about the threads in the nipple because the liquid would never come in contact with the nipple at all (well except for the interior surface of course). I wonder if this would seal better because any leakage would have to seep through a directly clamped surface, unlike the OP diagram where you are blocking leakage that would flow perp to clamping surface, ie along the outer surface of the nipple "under" the o ring.

Not that I've heard of any problems with the orig design but I was just wondering...

In theory, that extra o-ring would fix the problem but there's not enough flat surface on the end of a coupling to tighten against the oring without squeezing it out of place. If that were possible, there'd be no need for the interior flat washer.

 

[mariojr]

I have mine set up with an thin 'o-ring' I made out of a baby nipple between the coupling and washer. Works like a champ.

 

[zymurgy101]

Today I kicked it up notch and made the step toward AG. I used a ten gallon Rubbermaid water cooler, a "cooler conversion kit" from Rebel Brewer, a false bottom and a Blichmann Auto Sparge to complete the MLT.

The "cooler conversion kit" (http://www.rebelbrewer.com/shoppingcart/categories/Brewing-Equipment/Brewing/DIY-All-Grain/Cooler-Conversion/) included one o-ring and three SS washers. The picture on their website is not what is included currently. Moreover, the new kit is improved and is all SS. With all three washers and the o-ring on the inside, I still encountered leaks when I got more than five gallons of water inside. Also, the fit was loose overall and not really acceptable to use. So, at the beginning of brew day I took everything apart and instead of the included o-ring I used the original gasket that was on the cooler with the plastic nozzle. I turned the gasket around so that the part that previously went INTO the cooler wall was facing toward the SS washers and the bigger flat part of the gasket now faced toward the white plastic wall. I made sure the gasket was on the smooth part of the SS male to male connector and not over threads. The included o-ring was not quite large enough to cover the entire OEM hole whereas the OEM washer was just the trick...no more leaks! If you are having problems and would like a picture of what I did (if it doesn't make sense), let me know and I'll post something.

 

[toast]

I built this for the first time out of a Rubbermaid 10 gallon water cooler and she's watertight! One question though. When I added the 156 degree water, I heard a whole bunch of cracking coming from the internal insulation of the cooler, should I be concerned, or is that normal? Thanks.

 

[zymurgy101]

Yea, I heard the same from mine; however, I've had no issues.

However, once I used water that was too hot and it slightly warped the plastic inside. Note to self, don't use 200F water for preheating anymore. lol

 

[seabass1005]

Used your design because my Xtreme cooler leaked at the manifold. No more leak! Thanks!

 

[tre9er]

My cooler is leaking with the bargain fittings kit and I think it's due to cooler wall flex. I should note it did not have it's own spigot, I drilled the hole (which is tight around the nipple). I'm going to pick up a piece of 3/4" pvc tonight as well as some more o-rings (trashed mine overtightening) and possibly a flat silicone washer. Will report back.

 

[Bobby_M]

Even if you can't get the PVC ring to work, you can carve out some insulation and pack it with epoxy, JB weld, whatever. Something needs to keep the walls from getting clamped.

The design in the first post uses that pvc spacer to have the assembly actually clamp down completely on the inner wall. The hole in the outer wall just serves to keep everything from moving around.

 

[tre9er]

if I can find some flat flexible washers that are food safe and high temp safe are those preferrable to an o-ring?

 

[Bobby_M]

If you can't find any, it would cost you $2.43 shipped on my sight for a silicone flat washer. Yes it is much better than an oring.

 

[edmanster]

if I can find some flat flexible washers that are food safe and high temp safe are those preferrable to an o-ring?

I make my own out of the silicone bake ware from the dollar store and hole punches

 

[tre9er]

Tried this tonight, still leaked. Tried then putting ss washer against inner wall to make flat contact point for o-ring, still leaked but better. Def is leaking into cooler walls. Cooler has tiny holes in bottom of outer casing and water/bubbles coming from there.

Thinking of removing a section of outer wall, insulation, and cleaning up outer surface of inner wall, then installing silicone gaskets on both sides of inner wall, with ss washers behind each, then put all back together.

What sealant/adhesive is high temp and food safe that I could back the gaskets with as added sealing?

Saga continues.

 

[tre9er]

I know silicone caulk won't adhere to the wall of the cooler, but it should serve as a custom gasket, right? In that it will conform to the contours/cracks/crevices available prior to curing. I was thinking of putting some around the nipple on either side of the inner cooler wall, then adding silicone washer on both sides, then ss washers behind those, locknut behind inner assembly, PVC behind exterior, then locknut and ball valve on outside. Should work well, right?

 

[tre9er]

Bought two pack of small baby bottle nipples. Cut just after widest point. Placed this against inner cooler wall, followed by ss washer, locknut. PVC union between cooler walls, ss washer, ball valve. No leak so far with 3 gallons of water and some beer bottles for extra displacement. Also: triple wrapped threads, even though the locknut is probably bottomed out and the new "gasket/washer" is very tight on the nipple. From earlier leaks using o-ring, I feel the water was NOT travelling the threads, rather coming in from the sides. This new washer seems to easily solve that, and being food grade silicone that is normally boiled to sanitize, I know it can withstand the temps.

 

[wgeronimo]

I was hoping somebody here could offer some advice. After fiddling with this design for a few hours I am pretty frustrated. The point of weakness for me in building this design appears to be between the locknut and the ball valve. Water travels down through the spigot, hits the closed ball valve and looks for somewhere to go. This is the only spot that does not have a oring on it. So it just seeps between the cracks and out over the lock nut. After a lot of testing I am fairly convinced the actual seal between the cooler walls is sound.

Has anybody else run into this?

My current configuration is as follows.

ball valve ------ lock nut -------oring -------cooler wall-------oring------igloo washer-----stainless washer-----barb

I am using this kit from Ritebrew.

Other than constantly reapplying teflon tape what can i do?

 

[Palefire]

So you think water is leaking out of the back of the ball valve? If so, I'm not sure what else would fix that, other than teflon tape. Give the nipple 6-7 good layers of teflon tape before you screw anything onto it. That's always fixed whatever problems I've had.

I'm no plumber, though, so maybe someone else will have a better idea,

 

[Bobby_M]

All you need is teflon tape on the threads under the locknut.

 

[BockBurner]

Just finished mine up. Great plans. I just modified it slightly due to some part availability and ended up with a fantastic seal using some grommets and O-rings. Thanks for the post.

Edit: Did my second all grain batch today. Efficiencies are right in the ballpark, so the braided SS hose is doing a bang-up job. I always hit it and beat it up a little stirring the mash and it is holding up just fine with no internal wire or other support.
Love the new system. Can't thank you enough for posting such a great conversion. Awesome.

JB

 

[MikeyMike]

thanks so much. works great!

 

[WileECoyote]

Thanks Bobby M, Im going to need this, building a mash tun soon.

Cheers :cross:

 

[eyedoctodd]

Hoping for some advice on widening the existing spigot hole in the cooler wall. I'm building this from a coleman xtreme 72qt cooler (so I can make 10 gallon batches of bigger beers and still have a reasonable water:grain ratio).

The cooler wall is exactly 1 inch thick. The existing hole with the spigot removed is 24.5 mm in diameter by my digital caliper. I'm going to need to widen the outside plastic wall to 1 1/8" (28.6 mm) to accommodate the nipple and PVC sleeve.

Since there's already a hole there, I don't know how I would center a spade bit or hole saw. Would I use a step bit for this? Or do you think I could get away with incrementally grinding away the outer wall plastic with a dremel tool until it is wide enough? How about the insulation - just do it rough and dirty with an Xacto knife?

Thanks for any tips!

 

[wilserbrewer]

Very coarse round file rasp, or An aggressive dremmel bit would work as well...I don't think a knife would cut it..