drilled stopper won't stay down in the neck of my carboy

So I have (2) three gallon carboys that I think were both made by the same outfit in Italy, but I bought them one year apart. I bought them from my local HBS. I find that in one I can't get the drilled stopper to stay wedged tightly in the neck - it slowly sqibbs out. In the other it will stay wedged in there. This is true for both of the stoppers I bought - one is a solid rubber bung with a hole drilled through it for the airlock and the other is some kind of molded plasticy/rubber deal that isn't solid and has a little "chimney" that comes up in the middle to hold the airlock. (That is a really stupid description but I don't know how else to describe it Clearly the tolerance of the neck ID differs slightly.

So does anyone else have or had this problem, and what to do to create an airtight seal?

Thanks for your help!

 

I had this problem the first time I brewed and there were 2 different problems. One was that I had a 7.5 stopper and it was too big, i got a 7 and it worked fine. The second problem was the stopper was wet with starsan and too slippery to stay, when i got the right size stopper and let it dry before putting it in it worked fine.

I have since changed to universal stoppers instead of the big rubber bungs and i like them much better. They work great and have a lower profile than the bungs.

 

when the stopper and carboy are wet with stars they will not stay in.

Bugged me enough to stop using them. Switched to carboy caps. Problem solved.

Once the stopper and carboy neck are dry they will fit nice and snug and give a good seal.

 

Agree w/Gavin. I do occasionally use 1 gallon carboys and either have to use the screw tops which tend to break or use the rubber stoppers.
What i do is secure the stopper with a rubber band. stays secure and will not pop out. Or you can use a zip tie. They are actually easier to use vs tying a rubber band.

 

Thanks, guys, That helps. I just happened to see that somebody else had the same problem in the "general" forum with similar replies. I think I will get one of those orange caps.

 

I had a similar problem with the stopper working itself out.
My solution was to first insert the stopper as far as it will go in, and then insert the airlock into the hole last.
This seems to expand the stopper for a tight reliable fit.

 

I agree with what farther said. The universal bungs are awesome. Can be dripping in starsan and stays in the carboy.

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The stoppers are great but I still use the regular bungs for my airlock. I just wipe the inside of the carboy neck with some clean paper towel and dry the bung as well. Works fine and stays in.