The many uses I’ve discovered for caulk had me finding out that it does indeed expire.
There’s a very effective and easy way to find out if it has expired, after which confirmation you would need to deploy a specific method for the removal of any expired caulk.
Caulk Storage Best Practices
I’ve noticed how many people simply place silicone tubing under the sink or in large cabinets where the tubing can be easily stored upright.
I’ve come to learn that it’s best to use open tubes of caulk within two months.
Unopened tubes can be stored for up to one year if stored above freezing.
Most manufacturers list an expiration date on a tube of putty, but if you have an undated tube of putty, you can take the risk of buying a new one or test the strip on a hard surface first.
Testing the Caulk
You can make sure the putty is good by testing it on a piece of scrap and making sure it hasn’t hardened in the tube.
You can always test the putty before starting a project by applying a small drop of putty to a piece of wood, cardboard, etc.
However, it can take 1 to 10 days for the putty to fully set or dry, depending on the formula – in other words, when it will be completely waterproof and ready to use.
With these sealant products it is usually possible to apply paint after 30 minutes, while with polyurethane putty it is necessary to wait 7 to 10 days for the surface to harden before painting.
Typically, silicone and acrylic latex putty can dry to the touch within 30 minutes after exposure to air, depending on how humid or well-ventilated your space is.
I would not recommend that you expose the silicone to moisture until the filler has completely hardened in order to ensure its complete “waterproofness.”
Dealing with Different Conditions
Caulking in the winter, when the air is often drier, may take longer for the silicone to harden, but do not try to speed up the process by adding heat (such as with a hair dryer), as the heat will soften and potentially dissolve the silicone.
Also, it depends on how you store it; Factors such as hot or too cold environments can affect the shelf life of sealants.
If the putty has not formed a crust, it is most likely past its expiration date, which means the putty will not harden (dry) once you try to use it. You can also tell if the silicone is past its expiration date by looking at the consistency in the tube.
If you want to know if your putty has expired, feel the consistency in the tube, and if it has hardened, do not use it.
You can also try by squeezing out a small amount and waiting 15-20 minutes, then check to see if skin has formed.
You will usually find that the silicone putty starts to harden when it is over a year old, and even inside the tube.
This means that you probably won’t even be able to use the silicone putty properly if it’s been more than a year since you bought it. This is fine, but understand that open silicone tubing will deteriorate faster than unopened silicone.
If you try to apply putty but nothing comes out of the pipe because it has hardened, then the putty has deteriorated.
This type of putty will not resist and will be ineffective in this case. However, this mastic does not withstand either heat or cold, so this type of mastic can only be used for interiors.
If you just need a pinch of putty, you can simply squeeze it by hand and apply with your hands.
What it Comes Down to…
If your putty is out of date, or even within months of its expiration date, try it first.
If you open it, it will go bad after a few months, if not open, it will go bad in a year or two, but that depends on where you store it and the formula you use.
You should look for an expiration date on the tube so you know when it will go wrong.
When buying mastic in a store, be sure to check the dates on the pipes.
So Caulk Does Expire?
Yes, caulk can expire however most silicone sealants will last at least 20 years, but you might want to check your windows and bathroom first to make sure there are no gaps anywhere.
Old silicone and latex sealants can degrade in quality even inside a sealed tube and never fully cure.
A wider strip of the new putty will cover the old and stick to un-printed surfaces on each side.
This means that the silicone putty will not work as intended and will no longer be used as a sealant. You must completely remove all expired silicone using isopropyl alcohol if necessary.