I recently had to refit my bathroom sink as part of a complete remodeling project my wife insisted on finishing and as I was getting around to sorting out the drain and pipe connections, some of which were new and some being reused, I found that some of the joints which were over 10 years old still had wet plumbers putty on the surfaces.
This made me wonder, does plumbers’ putty ever dry out? and how long does it last? So I did some research and here’s what I found out,
Plumbers putty is a non-setting compound used for sealing sanitary joints. Due to its composition, it does not dry out. Plumbers putty is used in the installation of sinks, taps, drainpipes, and valves, and seals areas exposed to non-pressurized water, helping to prevent any leaks or seepage.
Plumbers putty is a useful addition to your plumbing tool kit and can be used to help when installing new pipes or fittings, find out more information on how long plumbers putty lasts and how to use it in our in-depth guide.
Does plumber putty dry out?
Due to its chemical compound, which has a specific gravity of 2.0g/cm³, plumbers’ putty does not dry out but instead, it remains permanently flexible, this allows the putty to help seal joints that can have some movement.
Having the ability to stay moist and flexible however also means that it cannot be used as the only method of joining two items together, as it has very little mechanical strength and should always be used in conjunction with a mechanical joint, such as screwed fixings or clamps.
Plumber’s putty is also not recommended for use on high-pressure joints as the putty will simply be forced out of the joint, and some other method should be considered such as a screwed connection, compression fitting, or push-in fitting with a dedicated seals such as an ‘O’ ring arrangement
Under normal use and circumstances, plumbers’ putty will remain flexible and liquid, however like most compounds or anything really, if enough heat is applied or it is left for long periods of time it will degrade and lose its ability to flex and seal.
It is not therefore for any other purpose other than to help seal low-pressure plumbing joints.
Plumbers putty is often light brown or beige in color, and can be purchased in small 750g tubs either online or is available from most plumbers merchants or hardware stores.
One major manufacturer, Bostik recommends that a tub of plumbers putty can be stored for up to 24 months without any issues or problems and this also the recommended shelf life for an unopened tub according to other suppliers.
For the best shelf life and results when storing plumbers putty, the containers should remain unopened and kept in cool dry conditions between 41℉ (+5°C) to 73℉ (+23°C).
Bostik also recommends that containers are stored out of direct sunlight and protected from frost as this has the potential to reduce the shelf life and the performance of the product.
How to use Plumbers putty for best results
According to Bostik the best way to use plumbers putty is to ensure that all surfaces are clean, dry. Any loose materials such as old sealant, dust, or dirt should be removed along with any traces of grease.
This is best achieved by wiping the area to be sealed with a clean cloth and then followed by a final wipe over with a piece of Plumber’s Mait, which will help to pick up any traces of dirt leftover.
To remove any old putty give the surface a good scrape clean with a flexible metal blade, then use mineral turpentine applied to a paper towel to remove any remaining putty residues.
it’s a good idea to wear gloves and always remember to wash your hands using soap and water after using chemicals.
Once the area is clean, then the putty can be worked gently by rolling it in your hands and creating a long thin strip, a bit like the ‘Play-Doh’ sausage rolls you made as a kid, and pressing it into place around the drain or area to be joined and sealed.
It’s best to use plumbers putty in temperatures above freezing and manufacturers suggest that the best results are obtained when the putty is applied between 41℉ (+5°C) to 86℉ (+30°C).
Apply gentle pressure to the putty to ensure it is secure and will stay adhered to the surface, then the second part can then be applied to form the joint
It’s a good idea to get even pressure applied around the joint to provide as good a seal or joint as possible. Then ensure all fixings are tight and secure.
Once you are happy the putty is evenly applied and there are no gaps or issues then any excess putty can be removed either with a putty knife or a cloth.
Which joints should you use plumbers putty on?
For best results, plumbers’ putty should be used on ceramic surfaces and is not recommended for use on plastic or porous stone such as granite as it can cause staining or accelerated fatigue when applied to plastic, which can lead to cracks and leaks.
Plumbers putty is regularly used to help create seals between sinks, bath fittings, or vanity units, and around taps and drains to help seal them and prevent water leaks.
The putty is not to be used for connections or joints between pipes that are used for supplying hot or cold water. These have typically much too high pressure and are clean water supply which is not what plumbers putty is intended for.
Putty can be used at the base of taps and other sink features before setting them onto the sink. Plumber’s putty can be used on drains in kitchen and bathroom sinks, in bath drains and to help seal toilets to bathroom floors.
To use plumbers putty when connecting the toilet pan to the soil pipe, first use untarred hemp, which should be packed evenly around the toilet spigot to give a fully secured and supported joint, with a concentrated fit.
Then apply Plumber’s Mait over the top of the hemp, this should then be packed well into the gaps using a putty knife making sure to fill any holes or gaps and form a sealed surface, this can then be smoothed off for a nice professional finish.
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What are the advantages and disadvantages of plumbers putty?
- Plumber putty does not dry out
- It remains flexible and moves with joints over time
- Can be used for taps, drains, sinks, and toilets
- No need to wait for it to dry installations can be used immediately
- Plumber putty is easy to use and apply
- It can be easy to remove and reseal if required
- Works well on ceramic surfaces
- Plumbers putty does not provide adhesive strength
- Not to be used on high-pressure joints
- It should not be used on plastic pipes or fittings
- Doesn’t seal the space between a wall and sink or bath unit
- It can stain porous materials like stone or granite
- Is not for use in submerged or exposed areas.
- Not for external use or in direct sunlight
- Cannot be painted
This article was written by: Richard Quinton – The DIY Help Desk Owner, Engineer & technical specialist.
Richard is one of the key partners in The DIY Help Desk team. He is a qualified Engineer, writer, and publisher, educated to Master’s level. He is a keen advocate of DIY and home improvements.
Richard enjoys helping others to learn new skills and reach their goals and believes that passing his knowledge and experience on through his writing is an effective way to positively impact the lifestyles and well-being of others on a larger scale.