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Plumbers Putty vs Silicone Caulk – In-Depth Comparison

plumbers putty vs silicone caulk
Written by Kai Michel

Though both are found in the plumbing aisle at your local hardware store and often carried together by plumbers these items are not transferable.

They are made of different ingredients, are applied with different methods, and serve different purposes.

Here we are going to explain which one you should choose based on the task at hand.

What is Plumber’s Putty?

Plumber’s putty is the go-to sealant for a variety of plumbing jobs including, but not exclusive to, connecting pipes, taps and plug holes to sinks and bathtubs.

Pros and Cons of Plumber’s Putty

Pros

  • No hardening

It stays flexible with your seal and is less likely to crack over time.

  • No shrinking

It is less likely for gaps to appear and the seal become useless.

  • No drying out

You can easily remove the putty when required.

  • No crumbling

This means it will maintain the seal for longer.

  • Ease of dismantling plumbing parts

The putty won’t cause difficulties when it is time for a change.

Cons

  • A non-stick product

This means that gravity will dislodge it.

  • Can stain

There have been recent developments of stainless putty, but it has not been around long enough to determine any long-term issues.

  • Unfit for plastics

Some of the ingredients used in putty can react with plastic leaving it worn and weakened.

  • Doesn’t repair leaks

It is unsuitable as a long-term fix as water pressure will dislodge it.

  • Unsuitable for large area coverage

It is non adhesive and so will not stay in position for long without being held in place by weight.

What Is Silicone Caulk?

Silicone caulk is a sticky adhesive sealant that dries into a tough elasticated material and is often used for securing plumbing fixtures to ceilings and walls. This can be found around the edge of bathtubs and shower tray.

Pros and Cons of Silicone Caulk

Pros

  • Adaptable to heat

It can withstand fluctuations between higher and lower temperatures without damage.

  • Strong insulation

Wherever you use it, provided used correctly, it will prevent loss of either desired heat or cold.

  • Incredibly durable

If used correctly it will last longer before any repairs are required.

  • Aesthetically pleasing

If you follow the instructions, you can create a professional finish. With 61 colors to choose from you are sure to find one to fit your purpose.

  • Water repellent

It is great at keeping rain and moisture from cracks or crevices they shouldn’t be. It also creates perfect seals for bathroom fixtures like shower bases and bathtubs. You can even use it to repair aquariums.

  • Low chemical reactivity

This means that it doesn’t contain many VOCs (Volatile Organic Compounds) that could react to their surroundings.

Cons

  • Strong odor

This has been known to emit and odor that can cause dizziness and, due to this, contractors often opt to use a more expensive odorless caulk.

  • Poisonous

It is a chemical formulaic product and if ingested can be harmful. Like many household products it must be kept out of reach of children and animals while it dries.

  • Repels paint

Being an oil-based substance means that silicone caulk is not suitable for areas you wish to paint over as paint will not adhere to the caulk due to the oil.

  • A long wait

It is generally advised to leave silicone caulk for 24 hours to dry. However, if the air in its surroundings lacks enough moisture, then it could take double that time.

  • Stubborn removal

With the positive of it holding fast and sure for a good length of time comes the negative that when you do need to remove it then it can be tough.

However, a good Stanley knife and scraper should be able to complete this task or even better, a silicone solvent.

Plumbers Putty vs Silicone Caulk: How Do They Differ?

Plumbers putty vs silicone caulk How do they differ

Dry time

The chemicals found in each product dictates the drying time.

  • Plumbers putty

Clay-and oil-based, plumber’s putty requires no drying time

  • Silicone

Silicone is a synthetic polymer of inorganic and organic compounds which is what requires the drying time while.

Note: This should not be something that dictates your decision on what to use. Always use the right product of the job.

Chemical makeup

The two similar products are very different in their chemical makeup which is why they must be used correctly for the purpose each was designed.

  • Plumbers putty

Plumber’s putty is created with elements of talc, limestone, and fish oil

  • Silicone

Silicone caulk is made from hydrogen, carbon, and oxygen polymers.

Application

Both are fairly simple to apply so long as you follow the manufacturer supplied instructions.

  • Plumber’s putty

Plumber’s putty is very flexible and easy to use. Simply create a rope of it in your hand and lay it in place. If you are not precise, then you can easily adjust it as it is non-adhesive.

  • Silicone

Silicone caulk is best applied with a caulking gun but be warned to have your area prepared to do a whole edge in one go as it is difficult to adjust after.

Also remember that pressure may still be leaving the tube after you have finished so have some paper towels to wipe the end clean.

Water resistance

Both silicone caulk and plumber’s putty are waterproof as expected but silicone caulk has a slightly longer life span.

  • Plumber’s Putty

Plumber’s putty is suited to smooth and regulated pressure.

  • Silicone

Silicone caulk is better for dealing with stronger and variable water pressure.

Toxicity

You should always read the label of all products to clarify exactly what it contains.

  • Plumber’s putty

Plumber’s putty is generally non-toxic as it is a mix of oil, clay and limestone but some manufacturers will add chemicals that make it more resilient to water.

  • Silicone

Silicone caulk can also vary. Some chemicals in silicone caulking can cause asthma and cancer so always double check.

Harmful compounds

Please make sure you secure your working area from children and pets when using silicone caulk.

  • Plumber’s putty

You will generally be safe using plumber’s putty due to its organic ingredients but always double check that label for any additional chemicals.

  • Silicone

If you are using silicone caulk, then remember to keep the area secure from children and animals while it dries.

UV exposure

When it comes to an outside job then both products were not made equally.

  • Plumber’s putty

Organic compounds found in plumber’s putty is unsuitable for use in UV protection as they are liable to shrink when exposed to the sun.

  • Silicone

Silicone’s inorganic compound and more adaptable to heat and rays and so has a high resistance to the sun.

Odor and color

Plumber’s putty will not be seen or smelled. Silicone will be both though the odor is temporarily.

  • Plumber’s putty

Plumber’s putty is not used for exposed areas and therefore the color is of no importance. Plumber’s putty is odorless.

  • Silicone

There are approximately 61 varieties of shade and color to choose from when buying silicone caulk including transparent.

Silicone caulk does come with an acidic odor that smells like vinegar but it only lasts for about 3 days.

Durability

Both products are tough enough for long lasting repairs if used correctly.

  • Plumber’s putty

Plumber’s putty is extremely durable as the putty remains in a malleable form.

  • Silicone

Silicone caulk is less durable as it loses flexibility once dry and can be worn down by heavy water exposure.

Maintenance

Plumber’s putty can be easily moved by hand whereas you will need tools and patience to remove silicon caulk.

  • Plumber’s putty

Plumber’s putty is far superior in the maintenance stakes as it is much easier to remold, remove or replace due to it not drying out.

  • Silicone

Silicone caulk will require scraping tools and elbow grease to remove the old seal and lay a fresh new one.

Price

As stated above these two products serve different purposes and so the best economic option is to buy the right product in the first place as the price will soon rise if you have to keep repairing or replacing.

  • Plumber’s putty

Plumber’s putty is cheaper to buy and easier to use so it will keep the labor costs down if you are not into DIY.

  • Silicone

Silicone caulk will cost more but you will tend to use less on area ratio.

When to Use

When to use plumber’s putty

  • Faucets on sinks and baths
  • Drains on sinks, bathtubs, and showers
  • Unexposed areas that require water sealing

When not to use plumber’s putty

  • Where you need adhesive strength
  • Areas exposed to UV rays
  • To repair cracks or gaps
  • Where gravity will dislodge it

When to use silicone

  • Shower trays, bathtubs or sink edges
  • Various surfaces that require water resistance like wood, glass, and marble
  • Exposed areas that require resistance to high water pressure

When not to use silicone

  • In unexposed areas as you will not be able to easily access the caulk when you need to repair or replace
  • On surfaces that you wish to finish with paint

FAQs

Q. Does plumber’s putty harden?

If plumber’s putty is correctly installed as instructed then it shouldn’t harden. Basically, don’t use it in exposed areas.

Q. How long does it take for sealants to dry?

Plumber’s putty does not dry and so time is not a factor. Silicone caulk generally takes 24 hours to dry but factors such as air moisture can extend this time to nearly 72 hours.

Q. Why can’t you use plumber’s putty on plastic?

Due to the organic makeup of plumber’s putty, it is unsuitable for use on plastics as it may react and leave staining.

About the author

Kai Michel

Hello, this is Kai, addressing homeowners in need of some help with their home renovation projects. I’ve worked on numerous toilet repair projects over the years that incorporated a wide variety of tasks, from repair to renovation and maintenance. Besides acquiring a degree on the legal codes and procedures, I gathered vast insights into bathroom settings, toilets, showers, fittings, and other household appliances, fixtures, and components. This helps me guide my clients through their home improvement and interior development plans. Since maintenance is my area of expertise, I can assist people in all phases of the actual ‘improvement’ process. To get my messages even further, I contribute to this site through my blog posts. Check my content here for expert suggestions!

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