# Big Mouth Bubbler lid - yet another solution, maybe the easiest

### Help Support Homebrew Talk:

#### passedpawn

##### Some rando
Not sure if this is still a thing that brewers battle. I have a Big Mouth Bubbler with the "universally annoying" lid. Kept popping up. I used a sprinkler donut to keep it down. Just dropped it on there and 100% success. Not sure if sprinkler donuts are available everywhere, but down here in the great free state of FL they are as ubiquitous as.. well, donuts.

#### Jag75

##### Supporting Member
HBT Supporter
Adapt and overcome. That's ingenuity right there lol!

#### Stormcrow

##### Supporting Member
HBT Supporter
That's cool. I'm more blown away though by the shear amount of fermentation in that picture. You must be a great neighbor.

##### New Member
You could try putting less water in the airlock, it will lower the pressure required to bubble out. Not by much, but it might be enough.

#### Maylar

##### Supporting Member
HBT Supporter
Big Mouth. I love it and hate it. 6 gallons of just about anything weighs like 75 pounds. But it's crystal clear, and easy to clean.

You're right, Shadow, a full airlock takes a surprising amount of CO2 pressure to bubble through. A concrete donut might well make that simple. My method has employed masking tape...

OP

#### passedpawn

##### Some rando
You're right, Shadow, a full airlock takes a surprising amount of CO2 pressure to bubble through. A concrete donut might well make that simple. My method has employed masking tape...
In theory, a 1" column of water in the airlock can be displaced by only 0.04 psi of pressure. (1 foot of water is 0.433psi).

Assuming that opening of my big mouth bubbler is 4", and the donut is 5#, it would take about 0.4psi to life the donut. (5#/ 2"^2).

So, the airlock will bubble way before lid moves. Of course, after doing the math, I'm sure I'll go out there now and find the donut blown off.

#### phbern

##### Supporting Member
HBT Supporter
I have the carrying strap for the Big Mouth. It flips over the top and locks down and keeps the lid from popping up It also has a hole so the airlock fits as well. And you can use it to carry the thing around as well. Works just fine.

#### PCABrewing

##### Recreational Brewer
Big Mouth. I love it and hate it. 6 gallons of just about anything weighs like 75 pounds. But it's crystal clear, and easy to clean.

You're right, Shadow, a full airlock takes a surprising amount of CO2 pressure to bubble through. A concrete donut might well make that simple. My method has employed masking tape...

View attachment 751628
Agree on the utility and ease of cleaning of the Big Mouth.

I used a couple tabs of Gorilla Tape when i was still using it.
The Sprinkler Doughnut is a creative idea too.

In theory, a 1" column of water in the airlock can be displaced by only 0.04 psi of pressure. (1 foot of water is 0.433psi).

Assuming that opening of my big mouth bubbler is 4", and the donut is 5#, it would take about 0.4psi to life the donut. (5#/ 2"^2).

So, the airlock will bubble way before lid moves. Of course, after doing the math, I'm sure I'll go out there now and find the donut blown off.
Is the doughnut concrete? Hopefully it clears the glass on the way down if it ever does hit .4 PSI

#### kartracer2

##### Supporting Member
HBT Supporter
Why doesn't some design geek make a Tri-clamp like gizzmo to fix what seems to be the biggest flaw the BMB has?
I went with Fermonsters (and are quite happy with them) because of that loosy lid situation. I wouldn't think that it would need to be as robust as a tri clamp, thinking plastic of some kind as the actual sealing is done with the gasket on the lid, right?. The main pieces could probably could be 3-D printed. Just spit balling here.
Cheers,
Joel B.

#### lawlthom

##### New Member
Why doesn't some design geek make a Tri-clamp like gizzmo to fix what seems to be the biggest flaw the BMB has?
I went with Fermonsters (and are quite happy with them) because of that loosy lid situation. I wouldn't think that it would need to be as robust as a tri clamp, thinking plastic of some kind as the actual sealing is done with the gasket on the lid, right?. The main pieces could probably could be 3-D printed. Just spit balling here.
Cheers,
Joel B.
I think this is what you are looking for: Link

#### kartracer2

##### Supporting Member
HBT Supporter
I think this is what you are looking for: Link
Yeah, those look like they would work well. A little spendy at \$3 a clip. Not quite what I was thinking of though. Looking at at the diagrams of the top/lid area, my idea might not be as good as I thought it would be either. Oh well, I'll stick with the Fermonsters.
Thanks for your time and Cheers,
Joel B.

#### balrog

##### Supporting Member
HBT Supporter
I guess I got lucky. Mine stays put. I empathize, as I can't imagine the annoyance at my system of purging a keg with ferm CO2 gasses, if the lid popped up to say "howdy" all the time.

#### PCABrewing

##### Recreational Brewer
Does anybody know if the Fermonster screw-on lid will fit the Big Mouth Bubbler? The glass version seeme to have threads but they start a bit low on the collar. But the plastic version the threads start right at the edge. Unfortunately I don't know the diameter of the Fermonster opening. Morebeer sells them for \$5, nice if it fits.
I don't use mine any longer so I'm not about to buy a lid just to check.

#### cayde1001

##### Supporting Member
HBT Supporter
On the old ones that did not come with the strap I had always used a 10lb weight and never had any issues.

If you buy one now they come with the strap that @phbern mentioned above and I agree that these work very well and keep the lid as tight as you need.

#### kartracer2

##### Supporting Member
HBT Supporter
The Fermonster neck is around 4" id. and 4.5" outside of the threads (+/- a smidge). Roughly 5 TPI. The BMB looks to be bigger than all that.

#### PCABrewing

##### Recreational Brewer
The Fermonster neck is around 4" id. and 4.5" outside of the threads (+/- a smidge). Roughly 5 TPI. The BMB looks to be bigger than all that.
I'll measure mine and post just for records sake.
I measured the BMB and the opening ID is ~5.25", Thread OD is ~5.75"

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#### PCABrewing

##### Recreational Brewer
On the old ones that did not come with the strap I had always used a 10lb weight and never had any issues.

If you buy one now they come with the strap that @phbern mentioned above and I agree that these work very well and keep the lid as tight as you need.

View attachment 752146
That almost looks like it was made for the job!

#### PCABrewing

##### Recreational Brewer
I have the carrying strap for the Big Mouth. It flips over the top and locks down and keeps the lid from popping up It also has a hole so the airlock fits as well. And you can use it to carry the thing around as well. Works just fine.

I have the carrying strap for the glass six-gal, I need to take a closer look. I did have to order it separately though. I bought it a few years ago.
I just clicked on the link you provided, that strap is different than mine. It looks like a nice improvement.