Most plumbing pipes are joined together using a threaded connection as they are convenient, quick to install, and require no special tools.
But one of the problems they face is that no matter how good the machining of the threads is, they run the risk of leaking. So plumbers use an additional sealant to protect the threaded connection further and prevent any risk of leaks.
Plumbers use pipe dope and Teflon tape as two of the most popular kinds of thread sealer. While both of these products aim to achieve the same thing – help seal the connection and prevent leaks, the way they do it and their intended use cases differ slightly.
The main difference between pipe dope and Teflon tape is that pipe dope is a chemical pipe thread sealant that is brushed onto the thread in liquid form, which completely seals the thread. This is usually used by professionals and for commercial applications.
On the other hand, Teflon tape comes on a small spool and is wrapped around the thread just like how you could apply regular tape to something. It’s a stretchy film that conforms to the shape of the threads. They are also commonly color-coded depending on what the pipe is supposed to carry.
What is Pipe Dope?
Most pipe threadings are pre-tapered during machining to provide a good ‘interference fit.’
However, because of various variations in machine tolerances and the kind of materials that will pass through the pipe, which can expand/contract the material as it heats up/cools down, people started to find that pipes would eventually leak regardless of the machine quality.
Pipe Dope was used to address this problem. It pulls double duty as an anaerobic chemical sealant, making any thread completely leakproof. Still, it also serves as a lubricant which makes the removal of the pipes easier in the future.
It fills in all the small gaps and voids within the threads so nothing can work its way through them over time. And it also makes the pipe more resilient to higher pressures.
Depending on their intended application, pipe dope can come in several types with different ingredients. For example, you will need to buy a specific pipe joint compound if it’s to be used for pneumatic connections, hydraulic, water, etc.
If you don’t use the correct kind of pipe dope for its intended application, it still runs the risk of leaking – so be sure to research what you need beforehand!
What is Teflon Tape?
Teflon tape, also known as PTFE or plumbers tape, is generally geared more towards plumbing and pipe threads and is less commonly used in larger industrial applications for pneumatics.
But it’s great for most general commercial applications, including pressurized water and heating systems.
It’s a polytetrafluoroethylene film that is then stretched around the pipe’s thread, and much like pipe dope, it will help fill in all the small voids and create a waterproof and pressure-resistant seal.
It also doubles up as a lubricant, making future disassembly easier and allowing the thread to be seated deeper than it usually would without lubrication. This lubrication also increases the lifespan of the joint by protecting both sides of the pipe from touching each other directly and wearing each other out.
It comes on a spool and is (usually) applied onto the male side of the thread in the direction it will screw into the female side.
There are a few different grades of Teflon tape available that you will need to be aware of. For example, the UK has specific regulations about which tape can be used for gas fitting – so you must ensure the tape you use meets those regulation standards of tape thickness.
This process is made a little easier because it’s commonly color-coded to help you ensure you have the correct grade of tape for the right application. Depending on which brand you buy, sometimes the spool/reel is colored, or for others, the tape itself might be colored.
- White: Your most common Teflon tape used for all general plumbing jobs.
- Yellow: Intended for gas lines such as butane, propane, and natural gas.
- Pink: A thicker thread seal tape for water lines creates a much denser seal inside the threads.
- Green: Tape that contains no grease and is intended for oxygen lines.
- Grey: A thick tape used for stainless steel. As stainless steel is such a tough material, the threads dig into each other a lot making them prone to seizing up and becoming stuck. This helps to lubricate them.
- Red: Designed for heavy-duty joints on ½” to 2″ pipes.
What are the differences between Pipe Dope and Teflon Tape?
While it’s pretty clear that both are intended for a similar application, there are many subtle differences between them. Depending on the type of pipe you seal, one may be more appropriate than the other.
Let’s go through these differences in detail so you can better understand how these products should be used.
1: Ease of use
Teflon tape is the easiest of the two to apply. This is why it gets used more frequently in residential applications and sits in every plumber’s (and homeowner’s) toolboxes.
It comes ready to go on a spool, and all you need to do is wind it onto the threads. It’s pretty mess-free, and its lubricating qualities mean you can easily unthread the seal and give it another go if you make a mistake.
On the other hand, pipe dope usually comes in a tin and is applied using a brush (although it can also be purchased in a tube applicator). This makes it a more messy affair and, as such, is more commonly used in serious commercial and industrial applications where the mess is less of a priority over the raw quality of the seal.
2: Intended use applications
There is tremendous overlap in what these two products can be used for. They both do a great job and, in many scenarios, are entirely interchangeable.
However, when it comes to heavy-duty applications such as industrial-grade hydraulic and pneumatic systems, you will commonly find Pipe Dope being used. This is because it’s manufactured with unique ingredients that make it specifically applicable to those applications.
Teflon tape isn’t manufactured with those heavy-duty applications in mind and is generally geared more toward home use on water pipes and central heating systems.
3: Meeting standards
Different countries have their standards that a pipe thread sealant should meet for it to be used for that particular scenario.
For example, with Teflon tape, there is a color code standard where the color of the spool indicates that that particular Teflon tape type is appropriate for a given use case. For example, there are different colors for gas lines, water pipes, etc.
Pipe dope also has standards it is expected to meet, and builders are expected to use the correct pipe joint compound for the right application, or it runs the risk of failing.
Unfortunately, there’s no simple color coding standard like Teflon tape, so you must research this yourself and ensure you’re using the correct type of pipe dope.
4: Relative strength
For many simple home applications, pipe dope and Teflon tape work great.
But as we get up to more demanding commercial and industrial settings, we see pipe dope being used more frequently than Teflon tape as it’s manufactured to be used in more challenging scenarios.
So a general rule is the more demanding a job gets – the more appropriate pipe dope becomes over Teflon tape as it is generally the stronger sealer of the two.
5: Easy to source
While you shouldn’t have any trouble sourcing either product, pipe dope is generally easier to source because it’s more commonly used by working professionals.
As such, there’s always some in stock in all your common retailers, including Home Depot, Lowes, and even Walmart.
6: Value for money
Regarding their prices, you will find both products are very similar in price.
We really have to consider the value proposition and which one will suit you best.
In terms of volume, pipe dope is better value for money due to the volume contained within a tin. However, as it’s a liquid in a tin, it does have the risk of drying out. So it’s better if you use it often and it won’t spend many years in storage.
Teflon tape, however, should last indefinitely, providing it’s stored away nicely. So if you use the product intermittently, Teflon tape is probably a better choice.
Pipe Dope vs Teflon Tape: Are they the same?
Pipe Dope is a stronger sealer that’s more commonly found in those big, heavy-duty industrial settings. At the same time, Teflon Tape is most widely used for residential applications thanks to its convenience and ease of application.
- Teflon tape is less messy, and easier to apply the Pipe Dope.
- Pipe Dope is more commonly used for hydraulic and pneumatic systems, whereas Teflon Tape is most widely used for simple water pipes and gas lines.
- Teflon Tape has a color coding system to help you meet the right standard for a given connection. Whereas pipe dope needs careful selection to ensure you’re using the right one; otherwise, the seal may be compromised.
- As a general rule, pipe dope creates a more robust seal than Teflon tape and is preferable for more demanding jobs.
- Pipe dope is widely used and, as such, easily accessible.
- If you need to use a pipe sealer often, then Pipe Dope presents a better value-to-money proposition. For intermittent use, Teflon Tape is ideal as it stores so well.
David Kessler is a CSLB licensed contractor with over 25 years of experience. He is specialized in home building, construction, and electrical works; he also has a keen eye for interior design and, over the years, has collaborated with various architects.
