Pipe dope is a commonly used sealant in plumbing projects that helps prevent leaks and ensures a tight seal between pipes. There are different types of pipe dope that work on a variety of pipe materials.
Whether you’re a professional plumber or a DIY enthusiast, understanding the basics of pipe dope is essential to ensure the success and safety of your plumbing projects.
In this PlumbingNav guide, we will cover:
- What is pipe dope and what does it do?
- How to use pipe dope?
- When to use pipe dope?
- What pipes can you use pipe dope on?
- Where you can buy pipe dope?
|What's In This Guide?
What Is Pipe Dope, And What Does It Do?
Pipe dope is a thread sealant used to join water and gas pipes to prevent leaks. Pipe dope is a paste-like substance that contains a mixture of lubricants, plastics, rubbers, and chemicals to form a tight seal. It’s also referred to as pipe joint compound.
Threaded pipe connections revolutionized the ease and speed of plumbing projects from the 1850’s. The secret was found in standardizing pipe threads. This propelled the plumbing industry forward, but there was still a small problem.
Water could still sneak past pipe threads when they failed to form an air-tight seal due to machining variances. That’s where pipe joint compound, also known as ‘pipe dope,’ swooped in to save the day.
Pipe dope is a retaining compound that creates a much-needed air-tight seal by filling these voids between joining pipes. It also lubricates threads during the assembly process.
This pipe-sealing agent has been used for many years and continues to be a popular choice among plumbers and homeowners alike.
Why is Pipe Dope So Popular?
- It forms a tight seal that prevents leaking
- It is resistant to temperature changes
- It can be used on a variety of different types of pipe materials
- It is relatively easy to apply – any novice DIY plumber can learn how to use it!
Pipe Dope vs. Teflon Tape: What’s the Difference?
Thread seal tape is an alternative to pipe dope that gained popularity in the 1960s. This is also known as Teflon tape, PTFE tape, or plumber’s tape. It is a thin, white tape that is wrapped around male pipe threads before they are screwed together.
One is not better than the other. The choice between pipe dope vs Teflon tape comes down to the specific material application, user preference, and budget.
Both pipe dope and Teflon tape come with their unique characteristics, advantages, and practical applications, making one more suitable than the other in specific situations.
Here are some of the advantages of each:
- It is a fluid substance that can fill gaps in threads more completely than tape.
- It’s typically easier to apply, especially in tight spaces.
- It’s more durable and less prone to shredding or tearing, reducing the risk of leaks over time.
- It’s incredibly pliant and can be molded to fit almost any thread configuration, ensuring a tight seal.
- It’s less messy and easier to clean up than pipe dope.
- It’s cheaper and more readily available in most hardware stores.
The choice between pipe dope and Teflon tape often depends on the specific application and the plumber’s preference. However, pipe dope is generally used more today in professional settings due to its durability and ability to fill gaps more completely.
Remember, it’s essential to apply these sealing materials carefully and correctly to ensure reliable, leak-free connections. Always ensure to follow the manufacturer’s instructions and safety guidelines when working with pipe dope or Teflon tape.
Overall, pipe dope is considered a more permanent solution than Teflon tape which is more of a temporary solution.
Pipe dope is also considered a safer option for drinking water supply lines due to the potential risk of PFAS interacting with your potable water.
Other Pipe Dope Alternatives:
The name pipe dope often gets used interchangeably with pipe sealant, thread sealant, and pipe cement. There are differences in these products, but all serve a similar purpose and should be selected based on the pipe material.
Shy away from “hacks” like electrical tape or silicone sealant in lieu of pipe dope or an appropriate thread sealant. Here are 3 solid options, below.
Best Pipe Dope Sealant Options by Pipe Material
It’s important to choose a pipe dope sealant rated for the pipe material you want to join. We’ve organized our favorite products according to which pipes you can use them on, and also highlighted what makes each special. Each of these has a pile of great reviews.
Venom VM08 Pro-Grade Soft-Set
|View on Amazon
Rectorseal 55972 PVC / CPVC Sealant
|View on Amazon
Oatey 31261 Blue Pipe Joint Compound
|View on Amazon
How To Use Pipe Dope
Pipe dope is an important part of your residential plumbing system and should be used whenever you are connecting two pieces of threaded pipe.
To use pipe dope, put a small amount of the material on the threaded connection of the fitting, then screw the fitting onto the pipe. It’s that easy!
The application process will vary slightly depending on the type of pipe dope you are using.
Here are some great tips that you can follow to ensure that your pipe dope is applied properly and your pipes will be tightly sealed and leak-free:
Tips & Tricks for Applying Pipe Dope
- Use the right pipe thread sealant for the job
- A small amount goes a long way – don’t use too much
- Only put pipe dope on the male thread
- Do not overtighten the pipe fittings!
- Wipe away any excess pipe dope with a clean cloth.
Quick Test: Is this fitting likely coming apart in the near future? Use Teflon Tape. Is this fitting long-term? Use pipe dope.
Pro Tip: Many plumbing pros prefer to use both Teflon tape and pipe dope for a “sleep well at night” absolute tight fitting. Gas fittings should use yellow tape and/or approved sealant for PSI ratings per local code.
Have an existing container of pipe dope, and wondering if it’s still good?
Pipe dope’s consistency is typically soft. If it’s hard or crumbling, you should discard it. Has it been sitting in a cold garage or work truck? It might just need to be warmed. Set it on your dashboard with the heat on for a short time. Stir it up well, and try a test application.
Watch the video below to learn more about using pipe dope and other sealants on threaded plumbing connections:
When To Use Pipe Dope
There are a few different scenarios when you might need to use pipe dope.
One of the most common is when you are connecting threaded metal fittings, such as when running water supply pipes or gas lines inside walls.
Other times you might need to use pipe dope include:
- When connecting pipes made from different materials
- When working with older pipes that may be corroded
- When connecting pipes that will be carrying hot liquids
- When sealing an underground storage tank
What Piping Materials You Can Use Pipe Dope On?
Pipe dope can be used on a variety of different materials, including metal, plastic, PVC pipe, copper pipe, and more. However, copper pipes typically use solder.
Choosing the right type of pipe dope for the material you are working with is important. For example, pipe dope designed for use on metal pipes may not be effective on plastic pipes and vice versa. You need to read the labels.
Do you have a large variety of different pipe materials to join, or are you unsure of what the pipes are made of that you need to seal? No problem. We recommend you go with an all-purpose pipe dope that will work on everything. Here is one below.
This is the best universal pipe dope/pipe sealant product to use for joining the largest variety of different pipe materials.
Can You Use Pipe Dope on PVC Pipe?
One of the most common questions we come across is, can you use pipe dope on PVC pipe? The answer is yes. While it’s a common misconception that pipe dope isn’t suitable for PVC pipes, it’s certainly possible and often recommended.
Why Use Pipe Dope on PVC?
Here are a few reasons why pipe dope is important when working with PVC:
- Sealing Power:
The primary purpose of pipe dope is to create a seal between PVC pipe threads. This prevents leaks and ensures a secure fit. Without it, you might find yourself dealing with unwanted leaks or loose-fitting pipes.
Applying pipe dope to PVC pipes provides lubrication which makes assembly of the pipes easier. It reduces friction between threads, allowing for smoother assembly and disassembly.
- Prevents Galling:
Galling is a common problem in plumbing where the threads of pipes get damaged due to excessive friction. Pipe dope helps prevent this by providing a layer of lubrication that protects the threads.
“The usage of pipe dope in PVC plumbing is about more than just seal and lubrication. It’s about ensuring the longevity of your pipes, preventing leaks, and saving money in the long run.”
Pro Tip: There is a difference between PVC and CPVC pipes, and the latter type has a different chemical composition for handling chlorinated water. Not all pipe sealants are rated for CPVC, and many homeowners can’t tell the difference between this and PVC.
For this important reason, we recommend using a pipe sealant rated for PVC and CPVC pipes.
We recommend this below pipe sealant for PVC and CPVC pipes, and it’s also rated for potable water.
Pipe Dope for Gas Lines: Is This Safe?
Many of you may wonder, “Is it safe to use pipe dope on gas lines?” The answer is yes but with some important considerations. Pipe dope can be safely used on gas lines for its sealing properties.
However, you should first confirm you’re using the right type of pipe dope specifically designed for gas lines, as not all joint compounds are suitable for this purpose.
When it comes to joining gas lines, choosing the right joint compound, often referred to as pipe dope, is critical for creating a secure and leak-free connection.
Consider the following key factors when selecting the right pipe dope for joining gas lines.
Choosing the Right Joint Compound for Gas Pipes
- Type of Gas: Not all joint compounds are suitable for all types of gases. Ensure to choose a pipe dope that is rated for the type of gas you are using.
- Pressure Rating: The pressure rating of the pipe dope must be suitable for the pressure of the gas line. Don’t assume that all pipe dopes can withstand all pressure levels.
- Temperature Tolerance: Depending on where the gas pipes are installed, they may be subjected to different temperature extremes. Choose a pipe dope that can withstand the temperature range in your specific application.
- Chemical Resistance: Some gasses can be corrosive. Ensure to select a joint compound that is resistant to the chemicals found in the gas you are working with.
Remember, the most expensive option isn’t always the best. Consider your specific needs and choose accordingly.
Choosing the right joint compound is vital for a successful and safe gas line connection. Always refer to the product specifications and consult with a professional if in doubt.
Below is a popular joint compound that is highly versatile for use on a variety of gas lines. According to the manufacturer it can be used on PVC, CPVC, ABS, polyethylene, polypropylene, iron, steel, copper, or brass threads up to and including 2 inches.
It’s also rated for up to 3000 PSI on gases, and 10,000 PSI on liquids.
Click this image to see the label and confirm it’s a good fit for your project:
Be sure to read all labels carefully before purchasing pipe dope to ensure that you are getting the right product for your project needs.
Where Can You Buy Pipe Dope?
Pipe dope is available at most big box retailers, hardware stores, and online through Amazon. It typically comes in either a small tube or a larger container.
The small tube will likely be sufficient if you are only using pipe dope occasionally, However, if you do a lot of plumbing or have multiple projects that require pipe dope, the larger container will be a more economical option.
Did You Know? The average household loses 10,000 gallons of water every year from leaks.
FAQ’s Regarding Pipe Dope
What is pipe dope used for?
Pipe dope is used when joining threaded pipes to prevent leaks at the connections. It is used in water pipes and gas pipes by filling in the threaded joint to create an airtight seal.
Is pipe dope better than Teflon tape?
Whether pipe dope or Teflon tape is better depends on the specific application. In general, pipe dope is better for use with metal pipes, while Teflon tape is better for use with plastic threaded pipes.
However, there are exceptions to this rule, and it is important to consider factors such as the type of substance being transported, the temperature and pressure of the system, and the size and material of the pipes when choosing between pipe dope and Teflon tape.
Teflon thread tape isn’t as long-lasting as pipe dope. For that reason, most plumbers prefer to use pipe dope for connections inside walls and permanent solutions.
Is pipe dope a permanent seal?
Pipe dope creates what is thought of as a permanent seal between pipe fittings. However, you can remove and unscrew pipes that were once joined by pipe dope. This can be done by using heat through a blowtorch, or a solvent, and torque. In this respect, pipe dope is as permanent as you’d like it to be.
Is pipe dope like glue?
Pipe dope is like glue and is sometimes referred to as pipe glue, but it is not glue. Pipe dope is an anaerobic adhesive that works as both a lubricant and sealant. Glue is used to bond two materials together.
Should I use pipe dope on brass fittings?
You can use pipe dope on brass fittings. You can use them on all metal fittings. Many products also work on PVC pipes. However, some products aren’t compatible with plastic or CPVC. Read product descriptions carefully before you make a purchase!
Meet Your Plumbing Navigator
About Plumbing Navigator
We’re passionate about all things plumbing, and love sharing tips, “how-to”, and reviewing the latest products to help make your project a success!
Learn More Plumbing Tips
Want to tackle more plumbing projects? Check out these helpful guides!