Loose carboy caps?

I decided to grab a few carboy caps from AHS with my last order. The orange ones linked here.

I snapped one onto my 5 gallon glass carboy, which has apfelwein merrily bubbling away in it. The fit was surprisingly loose. In fact, the only way I got bubbles through the airlock was to grab the cap and hold it down against the carboy.

I put one on a 6 gallon Better Bottle and it rattles on the neck.

Shouldn't these be tighter?

Thanks,

-Joe

I think the tolerance on them is really piss poor. I have a few that can easily be spun on the 6g better bottle. I have one that is really tight (that's what she said). I tried soaking the looser one in icewater for 30 minutes and it actually shrunk it a bit. I'd only be concerned with the loose fit if you're going for a long secondary but I've since been collecting water cooler bottle caps from the office. They fit REALLY tight and you can drill a hole for the airlock or blowoff tube.

I always wrap a thick rubber band around the recess as an extra precaution.

Edit: Not sure about the ice thing. So you chill it and it shrinks. Won’t it just return to where it was after warming to ambient temperature?

Mine fit the Better Bottle pretty well on the first use but it seems to get worse every time I use it. Maybe I'll try to ice water idea.

Bummer. The only reason I got these is so I wouldn't have to deal with stoppers slipping out and not sealing. If these won't seal, there's no point in using them.

-Joe

AnOldUR said:

I always wrap a thick rubber band around the recess as an extra precaution.

Edit: Not sure about the ice thing. So you chill it and it shrinks. Won’t it just return to where it was after warming to ambient temperature?

Click to expand...

I too would be skeptical but it stayed nice and tight for a 3 week secondary. I may have restretched it when I pulled it off but I have been using the water jug caps since then so who knows. I've even started putting completely unmodified caps on to my secondaries since I only move the beers when fermentation is deader than dead. No offgassing necessary.

I use them on the Better Bottle and use a strip of Glad Press and Seal Wrap to connect/seal the carboy cap to the neck of the bottle.

I've yet to try a cap, but why wouldn't a large heavy-duty zip tie work?

Or, even better, I'll bet that a large hose clamp, like those used on a car's radiator hose, would get the job done!

Hmmmm...might want to wrap a few layers of plastic tape around the cap first so that the metal slots in the stainless steel band don't bite into, or through, the rubber cap itself.

Pogo

Pogo said:

I've yet to try a cap, but why wouldn't a large heavy-duty zip tie work?

Or, even better, I'll bet that a large hose clamp, like those used on a car's radiator hose, would get the job done!

Hmmmm...might want to wrap a few layers of plastic tape around the cap first so that the metal slots in the stainless steel band don't bite into, or through, the rubber cap itself.

Pogo

Click to expand...

All but one of my caps fit tight the lose one I just put a zip tie around it.

Really they don't "need" to be tight.

All mine snap on tight each time. No problems with orange caps on better bottles. I do have to press hard, but the snap on great.

Bobby_M said:

I think the tolerance on them is really piss poor. I have a few that can easily be spun on the 6g better bottle. I've since been collecting water cooler bottle caps from the office. They fit REALLY tight and you can drill a hole for the airlock or blowoff tube.

Click to expand...

It must be poor tolerances, as I've got five and they all fit very snugly on both better bottles and 5g carboys, and yet this issue keeps coming up. If I ever end up with a loose one, I'll just use a zip-tie.

I've save a few of those water bottle caps too, they're bound to come in handy at some point.

I've got two and and haven't had a problem in over two years with 'em.

Still say this is the easiest solution. Goes on easy. Comes off easy. Doesn’t mark or damage the cap. The type of rubber bands used for lobster claws work really well for this.

Edit: I would not consider the zip tie idea. Actually might work too well. It’s nice to know the cap will blow off if excessive pressure builds up with a clog. That or a blown up carboy! (Could that actually happen?)

AnOldUR said:

Still say this is the easiest solution. Goes on easy. Comes off easy. Doesn’t mark or damage the cap. The type of rubber bands used for lobster claws work really well for this.

Edit: I would not consider the zip tie idea. Actually might work too well. It’s nice to know the cap will blow off if excessive pressure builds up with a clog. That or a blown up carboy! (Could that actually happen?)

Click to expand...

Even with the zip-tie they come off easy.

I noticed the caps for 6.5g glass carboys are smaller. It takes some muscle, but I was able to get one of these on a 5g carboy & it was very very tight.

Was at AHS yesterday & their smaller ones are red.