I hate to do this, but I need help with a mash tun leak

I'm using a 70qt Coleman Xtreme Cooler and I can't figure out how to stop the leak. I've seen other people use the same cooler, using the same fittings, and having no problems with leaks. It's been nearly a month and I've tried many different washer, o-ring, grommet configurations with no success. My leak is happening between the cooler body and the outer o-ring/washer.

I got the leak to creep to slow and it was just enough for me to try and brew with it. I brewed with it last week, successfully, but with a small leak the entire time. It was just enough to get part of a paper towel damp, not wet.

Here is a picture of the leak.


Here is a picture of how I have the whole fitting set up. Actually this picture is the most recent configuration I tried. Normally, I wouldn't have a second washer and that red o-ring on the inside-cooler end.


I didn't occur to me until yesterday to see how the inside of the cooler looked, around the hole. I noticed that there was something that looked a bit deformed. Not normal, is it?


Has anybody had leaking problems with this specific cooler or any other cooler and was able to find a solution? If nothing, I'm thinking about heading to Wal Mart after work to buy another one....=[

Get some food grade silicone and seal it. That's what I did with my cooler and never leaks,

slarkin712 said:

Get some food grade silicone and seal it. That's what I did with my cooler and never leaks,

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Any particular brands of silicone to look out for and would I just place it around where the rubber grommet goes?

I don't remember the brand of silicone that I used, but it might have been this:
http://www.homedepot.com/p/DAP-2-8-oz-Silicone-Aquarium-Sealant-00688/100128841
Just put it in any place that will be in contact with the interior wall of the cooler. I even put it around the steel washers on the inside an outside for further insurance. You don't want any liquid to get inside the cooler walls from the inside or outside.

The problem is the foam insulation between the inside and outside walls isn't strong enough to support the fitting. When you tighten the fittings, it's pulling the inner (white) plastic towards the outer (blue) plastic; the foam collapses under the pressure, deforms, and results in leaks.

Cut a bigger hole in the outer blue layer so that you're sealing up against the outer face of the white plastic rather than the outer face of the blue plastic. So your fittings will seal up against the inner and outer surfaces of the white plastic.

Your problem is in the bulkhead. I see a white washer in front of the red silicone gasket? It seems to me that the white washer/gasket has a lip on it to go into the hole where the bulkhead is, this is probably the original gasket for the plastic spigot that was on it, correct?

Remove that white plastic piece and use only the red silicone gasket, or two of those red silicone gaskets, you don't need a gasket on the outside of the cooler.

At this point, you may have a problem trying to get a good seal, it looks like you've tightened it so much that the white original gasket "dimpled" the inside of the cooler. You may need a larger red gasket to go around the smaller one. Basically, the smaller red gasket should be able to fit inside the larger one (the smaller one would only be used to keep the larger one centered).

That o-ring doesn't seal well in this scenario. I use a large flat one, the size of the washer, and still need silicone to prevent leaks over time. I even have a "sleeve" siliconed into the hole so I can tighten the nuts better against it.

You also need to use some teflon tape on the threads, as they can seep without.

I agree that it seems that the white piece might be keeping the red o-ring from sitting well against the inside of the cooler and the washers.

Also it looks like tightening things is pulling the white layer of the cooler toward the blue layer. You might be able to use a piece of cpvc tubing if you can find the right diameter. Cut the blue layer big enough to insert the tube and make the tubing the same length as the distance between the inner and outer layer of the cooler. Then the compression pressure would then be on the cvpc tubing, not on the foam insulation, and the inner o-ring should make the seal.

kh54s10 said:

I agree that it seems that the white piece might be keeping the red o-ring from sitting well against the inside of the cooler and the washers.

Also it looks like tightening things is pulling the white layer of the cooler toward the blue layer. You might be able to use a piece of cpvc tubing if you can find the right diameter. Cut the blue layer big enough to insert the tube and make the tubing the same length as the distance between the inner and outer layer of the cooler. Then the compression pressure would then be on the cvpc tubing, not on the foam insulation, and the inner o-ring should make the seal.

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That's what I did, saw it posted here by somewhere who has it on his blog. I found a piece of gray electrical conduit with the exact inside diameter to pass the bulkhead through. A PVC coupler may be the right fit too, I remember it being gray.

dmcman73 said:

Your problem is in the bulkhead. I see a white washer in front of the red silicone gasket? It seems to me that the white washer/gasket has a lip on it to go into the hole where the bulkhead is, this is probably the original gasket for the plastic spigot that was on it, correct?

Remove that white plastic piece and use only the red silicone gasket, or two of those red silicone gaskets, you don't need a gasket on the outside of the cooler.

At this point, you may have a problem trying to get a good seal, it looks like you've tightened it so much that the white original gasket "dimpled" the inside of the cooler. You may need a larger red gasket to go around the smaller one. Basically, the smaller red gasket should be able to fit inside the larger one (the smaller one would only be used to keep the larger one centered).

Click to expand...

The funny thing about the dimple in the inside of the cooler is I went to Wal-Mart yesterday to possibly buy another cooler. I thought I ruined my cooler with that dimple, but apparently, all the other 70qt Coleman Xtreme coolers had a similar dimple. I dunno if that's a normal thing they're doing with this generation of the coolers manufactured.

IslandLizard said:

That o-ring doesn't seal well in this scenario. I use a large flat one, the size of the washer, and still need silicone to prevent leaks over time. I even have a "sleeve" siliconed into the hole so I can tighten the nuts better against it.

You also need to use some teflon tape on the threads, as they can seep without.

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Someone on another forum suggested I get another 1/2" NPT flat silicone gasket. I'm probably gonna order a couple of these and try them out.

kh54s10 said:

I agree that it seems that the white piece might be keeping the red o-ring from sitting well against the inside of the cooler and the washers.

Also it looks like tightening things is pulling the white layer of the cooler toward the blue layer. You might be able to use a piece of cpvc tubing if you can find the right diameter. Cut the blue layer big enough to insert the tube and make the tubing the same length as the distance between the inner and outer layer of the cooler. Then the compression pressure would then be on the cvpc tubing, not on the foam insulation, and the inner o-ring should make the seal.

Click to expand...

Originally, I actually didn't use the red o-ring when I did my first mash in it. I tried to use it, but to no avail and I just had the red o-ring on when I took this picture.

I'll look into the cpvc pipe. I might have to look online for that since I don't think my local hardware stores have any that small, let alone have any cpvc.

AQUILAS said:

I'll look into the cpvc pipe. I might have to look online for that since I don't think my local hardware stores have any that small, let alone have any cpvc.

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I mentioned cpvc because it is food safe and heat safe.

If the seal is good wort will never touch the compression tube, so anything that will fit would work.

Mine also has a dimple and to make things more complex, the hole is slanted down a bit toward the outside by a few degrees, not giving perpendicular walls to seal against.

Although the large silicone gasket should give you a better seal the silicone caulk (aquarium grade) will be your friend ultimately. I don't mind the little drip as much as the majority of wort getting inside the foam walls.

Look for PVC conduit or PVC fittings rather than tubing. You need about 1 1/4".

What are you doing for lautering? A CPVC manifold with slots cut in the bottom?

kh54s10 said:

I mentioned cpvc because it is food safe and heat safe.

If the seal is good wort will never touch the compression tube, so anything that will fit would work.

Click to expand...

That's an awesome diagram, thanks for that. I'll definitely have to look it up.

Yeah I tried to ask for cpvc at my local home depot to make a hop spider with and the employee said they didn't have any. I'm not sure if he just said that because they really had none or if he had no idea what cpvc was.

IslandLizard said:

Mine also has a dimple and to make things more complex, the hole is slanted down a bit toward the outside by a few degrees, not giving perpendicular walls to seal against.

Although the large silicone gasket should give you a better seal the silicone caulk (aquarium grade) will be your friend ultimately. I don't mind the little drip as much as the majority of wort getting inside the foam walls.

Look for PVC conduit or PVC fittings rather than tubing. You need about 1 1/4".

What are you doing for lautering? A CPVC manifold with slots cut in the bottom?

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Ahh right on. I'll look for that pvc fitting size. What brand of silicone caulk to you recommend? My local home depot apparently has one, but in regards to it being food safe, it says "incidental food contact safe". Not entirely sure what that means for a prolonged high temperature food contact.

I BIAB in a cooler, so lautering is just pulling the bag out of the cooler.

DAP is a national brand for caulks, they make an aquarium safe silicone. It doesn't contain fungicides and stuff like that, so it's safe for fish. And us. It's a small hand tube, 6-8 oz maybe, not a magazine tube. Maybe an aquarium supply store? Walmart?

IslandLizard said:

DAP is a national brand for caulks, they make an aquarium safe silicone. It doesn't contain fungicides and stuff like that, so it's safe for fish. And us. It's a small hand tube, 6-8 oz maybe, not a magazine tube. Maybe an aquarium supply store? Walmart?

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Same as this one? My local home depot has this in stock. Someone in the comments section of this product said "The DAP Household and Aquarium Silicone is only rated for incidental food contact. For your purposes, you will need a NSF approved silicone sealant, unfortunately DAP does not offer a sealant with that rating. "

Yup, forgot to mention that you need to add teflon tape on the nut that presses against the washer to prevent seep through the threads of the nipple.

What you can also do is drill the hole outside of the cooler just slightly larger, leave the white liner portion alone. Insert a cpvc pipe from the outside of the cooler in so it will push against the white liner to push out the dimple as you tighten the bulkhead. That way the red gasket will create the seal against the white liner as it should.

Also, since the foam inside your cooler may have gotten soaked, drill a small hole on the outside at the very bottom corner of the cooler (don't go all the way through!) just so it provides an opening to allow draining. Once dried out you can seal it or leave it.

AQUILAS said:

Same as this one? My local home depot has this in stock. Someone in the comments section of this product said "The DAP Household and Aquarium Silicone is only rated for incidental food contact. For your purposes, you will need a NSF approved silicone sealant, unfortunately DAP does not offer a sealant with that rating. "

Click to expand...

That may work fine. You don't need much of it. Since you're not really exposing any or much of it to the wort, it's closing the small voids between the silicone gasket and the white inner wall, I wonder if just any silicone caulk would do fine in this application.

AQUILAS said:

Yeah I tried to ask for cpvc at my local home depot to make a hop spider with and the employee said they didn't have any. I'm not sure if he just said that because they really had none or if he had no idea what cpvc was.

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I got mine at Lowes. CPVC pipe and all the connections/fittings are usually the next aisle over from the standard PVC.

I had the same problem with my mashtun. I simply got a silicone washer that was the same inner diameter, but the diameter of the washer itself was much bigger. Essentially, the same size washer but much thicker. I'm sure what island lizard said would work to, use a flat long washer. I happened to have the thick one in my toolbox when I noticed the leak and switched the washers out and boom problem solved. I'm not usually lucky enough to have what I need on hand.

I ended up buying two Coleman Xtremes because I screwed the first one up and punched a hole in it. So now I have 2 of those rubber neck/gasket pieces that they come with.

Mine goes (starting from inside): Female NPT to the male/male 1/2" NPT (all the way through to the valve on the outside), metal washer, flat silicone gasket, rubber gasket that came with cooler, cooler wall, second rubber gasket, metal washer, ball valve...

Not even a hint of a leak. Can take a picture if you'd like.

TBH, depending on how big / fast the leak is - RDWHAHB.

I found out the hard way that overtightening will destory the bulkhead and make it all but impossible to seal without using some kind of silicone sealant. Mine leaks like that on occasion, usually if I put downward or upward pressure on the valve assembly.

If it's not flowing out heavily, put a towel under the bulkhead/valve assembly and call it a day.

RmikeVT said:

I had the same problem with my mashtun. I simply got a silicone washer that was the same inner diameter, but the diameter of the washer itself was much bigger. Essentially, the same size washer but much thicker. I'm sure what island lizard said would work to, use a flat long washer. I happened to have the thick one in my toolbox when I noticed the leak and switched the washers out and boom problem solved. I'm not usually lucky enough to have what I need on hand.

Click to expand...

I may just have to look into that. It's surprisingly hard to find silicone washers at my local hardware stores. Any place online you recommend to get those?

davidgaines said:

I ended up buying two Coleman Xtremes because I screwed the first one up and punched a hole in it. So now I have 2 of those rubber neck/gasket pieces that they come with.

Mine goes (starting from inside): Female NPT to the male/male 1/2" NPT (all the way through to the valve on the outside), metal washer, flat silicone gasket, rubber gasket that came with cooler, cooler wall, second rubber gasket, metal washer, ball valve...

Not even a hint of a leak. Can take a picture if you'd like.

Click to expand...

Sorry for the late reply, but yeah if you can take a picture, I'd like to see a picture of that set up. Sounds similar to how I had it set up except for a few parts.

DonnieZ said:

TBH, depending on how big / fast the leak is - RDWHAHB.

I found out the hard way that overtightening will destory the bulkhead and make it all but impossible to seal without using some kind of silicone sealant. Mine leaks like that on occasion, usually if I put downward or upward pressure on the valve assembly.

If it's not flowing out heavily, put a towel under the bulkhead/valve assembly and call it a day.

Click to expand...

It wasn't a big or fast leak at all. A little drip every now and then. I didn't drench the paper towel I had, just made it a bit damp, but it was enough to mess with my head.

I don't think it was anything to worry about, but I was just worried about wort getting into the cooler wall/insulation and making things all funky in there. I know I could just take the ball valve set up off after every brew and reassemble it back afterwards, but I'm trying to avoid that.

AQUILAS said:

I don't think it was anything to worry about, but I was just worried about wort getting into the cooler wall/insulation and making things all funky in there.

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That was my biggest concern too. Do you have a home brew store locally? That might be the best place to look.

RmikeVT said:

That was my biggest concern too. Do you have a home brew store locally? That might be the best place to look.

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There are a couple around here actually. I'll check with them.

After playing with multiple arrangements of fittings and various washers, I settled on a minimalistic arrangement and it's been leak-free for years. Two important points are: wrap all threads with several wraps with Teflon, and don't tighten the inside locknut too tight. The setup will be more loose than expected.

Inside (nipple, teflon, locknut, o-ring, cooler-supplied gasket):
View attachment uploadfromtaptalk1441909719929.jpg


Outside (nipple, teflon, washer, ball valve):
View attachment uploadfromtaptalk1441909766727.jpg

stpug said:

.

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Thanks good sir! The outside design looks the same as how I had mine. As for the inside, I tried that myself, but didn't give it a full shot. Might play around with that again today.

AQUILAS said:

I may just have to look into that. It's surprisingly hard to find silicone washers at my local hardware stores. Any place online you recommend to get those?

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I saw a few on amazon. You have to buy a handful of them, but they are out there. Seriously, check home brew stores, they sell stuff like that all the time.

Also, bargainfittings.com. I bet two or three of the large flat red 1/2" NPT would solve your problem (maybe even one).

http://www.bargainfittings.com/index.php?route=product/category&path=42

I was just doing some googling around, you can also purchase silicone sheets of varying thickness. You could find one of those and make a custom gasket by cutting it and drilling a hole in it....that would probably never leak.

RmikeVT said:

I saw a few on amazon. You have to buy a handful of them, but they are out there. Seriously, check home brew stores, they sell stuff like that all the time.

Also, bargainfittings.com. I bet two or three of the large flat red 1/2" NPT would solve your problem (maybe even one).

http://www.bargainfittings.com/index.php?route=product/category&path=42

I was just doing some googling around, you can also purchase silicone sheets of varying thickness. You could find one of those and make a custom gasket by cutting it and drilling a hole in it....that would probably never leak.

Click to expand...

I was actually recommended by someone in regards to those washers from bargain fittings, but i just couldn't justify spending a few dollars + shipping on washers. haha. I may just resort to that though. I'll have to check my local shops to see if they carry any.

AQUILAS said:

I was actually recommended by someone in regards to those washers from bargain fittings, but i just couldn't justify spending a few dollars + shipping on washers. haha. I may just resort to that though. I'll have to check my local shops to see if they carry any.

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We brewers rarely order just one thing. Keep a running short list of things you come across you "need," so when time comes, you can order the whole shebang.

Not sure if this will fix your particular leaking area, but I've made gaskets from that blue RTV (Room Temp Vulcanization) silicone. Use your SS washer as the receiver for the silicone, lay it on 1/8" thick and smooth it out as best as you can (soapy knife). Let it cure (hairdryer) and you've got something that may hold forever. Cover with the food grade stuff if you're concerned about those things.

AQUILAS, here's my setup for my Coleman Xtreme 52 quart. Keep in mind, the rubber insert towards the ball valve is completely unnecessary, I only used it because I had a second one.

Quick Photoshop job. Let me know if you'd like a larger version, original is 3000+ pixels.

@davidgaines that looks like a solid setup. I think what I need to get is one of those silicone flat gaskets. Question about your cooler: how does the inside of the your cooler wall spigot hole look like? Is it indented like mine? I went to walmart shortly after I made this thread and noticed that the other xtremes have that indent.

I'm gonna try to play around with my cooler again today.

AQUILAS said:

@davidgaines that looks like a solid setup. I think what I need to get is one of those silicone flat gaskets. Question about your cooler: how does the inside of the your cooler wall spigot hole look like? Is it indented like mine? I went to walmart shortly after I made this thread and noticed that the other xtremes have that indent.

I'm gonna try to play around with my cooler again today.

Click to expand...

The pic in the first post makes it look like it's a little deformed, but the large indent is normal. The silicone flat gasket makes all the difference in the world for me, in this Coleman Xtreme and my last round Igloo MLT. I know it really sucks to have to pay shipping on just a couple small gaskets, but it's all worth it. Seriously.

My previous Coleman Xtreme that I damaged in removing the spigot, looks like yours on the inside. I'm going to try food grade sealant on it to set up a second vessel.

Just an update. I played around with my cooler again yesterday, tried different variations of washer/oring setups, but to no avail. Actually, my first try, I thought I had done it right. No leak from between the cooler body/outside washer........then it started leaking between the two outside washers. I figured, "okay, I got it this time. I'll take it apart, put more teflon tape on the nipple, assemble it like I last time, and we'll be set!" Nope. For some reason, I couldn't replicate how I did it the previous time and this time the leak was from the cooler body. Either way, there was still water getting into the cooler wall from teh inside.

Defeated, I cleaned up, went inside, and hopped on my computer to order some things from Bargain Fittings. Ended up getting the 1/2" NPT flat silicone gasket, a large red 1/2" NPT flat silicone gasket, and a 1/2" NPS flange locknut for the inside-cooler part. Hopefully I get it in soon and it works....this leak is taking time away from my christmas old ale.