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The tube, which I bought in December 2021, says

Batch 21E11
Expiry 05/2023

I'm taking this to mean that it was produced one month before purchase, and at this time still has 15 months before expiry.

I cut an ample hole and, one minute later, squeezed, but it protrudes from the wrong end, as you see in the picture.

silicone will not exit

What might be the cause of this? Does it mean that it has solidified near the nozzle end?

isherwood
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Sam
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    Cheap latex you might not have to poke. But always with 100% silicone. – Mazura Feb 04 '22 at 07:00
  • @Mazura Does the cheapness of the latex correlate with the durability of the seal? – MonkeyZeus Feb 04 '22 at 15:10
  • Looks like you have your answer but this can also happen if the nozzle gets badly clogged. – JimmyJames Feb 04 '22 at 15:10
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    Solvent-based caulks (silicone, urethane) tend to have a seal behind the nozzle. Water-based caulks (latex, latex with silicone) usually don't. – isherwood Feb 04 '22 at 15:25
  • In manufacturing, it's much more common to label manufacturing dates with year and the week in the year rather than the year and just the month in which the product was made. Thus, the `21E11` is much more likely to be the 11th week in 2021 (e.g. perhaps batch "E", week 11 of 2021) than it is to be the 11th month in 2021. However, there's nothing that really says that "Batch" number includes a human-readable date code, even though the `21` tends to lend itself to being interpreted that way (i.e. it's quite likely to be a date code with a batch within the date, but we don't actually know that). – Makyen Feb 04 '22 at 19:40
  • @Makyen One of my suspicions was that the tube might have a five year shelf life, but that it had already solidified despite time remaining before the formal expiry. It would be interesting to know the maximum number of months that have been seen before expiry, to make sure that we buy "fresher" silicone—though that's not the issue in the present case. – Sam Feb 04 '22 at 22:44

2 Answers2

21

Did you cut the end, but not poke a hole in the seal down the nozzle at the end of the main tube?

That seems like the most likely reason for the set of things that happened here. Many caulking guns have a pin for the job of piercing that seal built onto them. Otherwise you need a stiff wire or long nail for it.

Ecnerwal
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    [We've already discussed this](https://diy.stackexchange.com/questions/3988/what-is-the-best-way-to-seal-caulk-tube). Let's not do it here again. – isherwood Feb 04 '22 at 15:26
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Most, if not all, caulk guns are equipped with an "opening rod" for breaking the seal in a tube of caulk, silicone, or whatever product you are using.

By leaving that seal intact you have created a situation in which the resistance to exit out the back is less than the front.

Sometimes this rod is too big for your desired tip size so you need to find something thinner which can puncture the seal.

enter image description here

MonkeyZeus
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