Introduction: Tools and Materials for PVC

About: I used to work for instructables.com, now I just make stuff. // follow me to see what I'm up to: https://www.echoechostudio.com

Welcome to the world of PVC Plastic Tube!

The acronym PVC stands for Polyvinyl Chloride. Polyvinyl chloride is a kind of plastic that is structurally rigid and non-corrosive. This means it's very strong and won't disintegrate from use.

Plastic PVC pipe is most commonly used by plumbers and clever DIY enthusiasts. This pipe material was designed to transport water because it won't wear out over time like rusting steel can. PVC is also structurally very strong. When parts are constructed properly, it can support structures that are hundreds of pounds!

This class aims to go over the material properties of PVC as well as the most common ways it is worked, machined, joined, and finished. By the end of this class, you'll be inspired to irrigate your garden, build creative pipe furniture, and more!

Settle in and let's learn all about PVC pipe!

Step 1:

The following lists all the tools and materials referenced or used throughout this course.

Personal Protection Equipment (PPE)

Cleaning and Prepping

Measure, Mark, Square, and Clamp

Cutting

Gluing

Pipes

  • PVC pipes are available at your local hardware store. You can get colored lengths of PVC online, more on that below (see furniture grade PVC).

Shaping and Connecting

If you'd like to see what else can be handy for PVC pipe projects, check out this list of tools and materials with other possible tool choices.

Step 2: All About PVC!

PVC plastic is available in many forms. This course mainly discusses how to work with PVC pipe, but the plastic is available in sheets, rods, and more. PVC is even available in thin, flexible fabric which makes it ideal for sewing projects (think rain jackets and water resistance).

Common PVC Pipe Sizes

You have lots of options when it comes to PVC pipe sizes, the most common are 1/2", 3/4", 1", 1 1-/4", and 2". The larger the pipe size, the more rigid and less flexible it will be. This makes thin tubes really useful for lightweight applications and small structures, but poorly suited to standing up to heavy loads because the pipe will flex. As the pipes increase in diameter, so does the inner wall thickness, making them stronger and more inflexible. For most projects, I use 1/2", 3/4" or 1-1/4". The smaller diameters bend and flex easily but still maintain some strength - good for hoop houses and gardening projects. The larger diameters are great for making structures or furniture because they will not bend and are very difficult to sheer. Larger diameters are also quite heavy and cumbersome. Be sure you're ready to carry big bulky pipes.

The wall thickness of your pipe and fittings is called the schedule. The two most common schedules are 40 and 80. Schedule 40 PVC is typically white, and used for residential and irrigation purposes. Schedule 80 PVC has a thicker wall, dark gray in color, and is used for commercial and industrial applications. It is wise to not mix schedule 40 and schedule 80 parts and pipes in one project, as they have different fit tolerances as well.

Besides rigidity, schedule 80's thicker wall also allows for a greater amount air or water pressure to flow through the pipe. Schedule 40 PVC pipe will be able to stand up to most tasks that you can imagine, but if you anticipate more than 300 psi of operating pressure, consider using schedule 80 pipes and fittings (unless you're making something very dangerous, or insanely strong, you shouldn't need it).

Step 3: Pipe Fittings

Pipe fittings are really what makes a PVC project. These little connectors unlock a world of possibilities when it comes to connecting different sections of pipe.

Grading


Furniture grade fittings from Formufit


Plumbing grade fittings from the hardware store

There are furniture grade fittings and plumbing grade fittings.

Furniture grade fittings are made out of a more scratch-resistant plastic and have no lettering or barcodes printed them. These are ideal for structural or design projects and come in a variety of sizes and shapes beyond your normal plumbing grade fittings.

The plumbing grade fittings are designed to never be seen, meaning they are used on pipe projects that go behind the wall or under sinks. These plumbing fittings have lots of raised text and sometimes even a barcode printed on them.

Kinds of Fittings

There are many kinds of fittings, from your basic tee, or straight pipe coupler, to 3-way elbows, or even 5-way connectors. Common bend angles of fittings include 90, 45, and 22. If you need to make a joint at a different angle, consider using a flexible coupler, if water needs to flow through your project or a more structural adjustable fitting that joins with a bolt, if your project needs to collapse or be set at an uncommon angle.

Adapting to Multiple Sizes and Beyond

As we learned above, pipe is available in many different diameters. Every once in awhile you will encounter a situation where you need to connect two different sized diameter pipes. This can be done with adapting or reducing couplings or bushings.

A coupling connection is made by connecting to the outside diameter of the pipe, while a bushing connection is made on the inside diameter of the pipe.

The same is true for and external end-caps and internal stop-plugs.

Most fittings you will find are called slip fittings. In these connections, the pipe easily inserts into the joint to be fastened together. You can also find threaded fittings. Threaded fittings are great for making modular structures, or adapting to other pipe materials like steel, brass, or copper.

You can also get all kinds of valves to stop and start the flow of water or air inside your PVC project.

Thinking about adding a water element to your project? Check out this outdoor dog shower from diycreators. This project uses a great mix of threaded and slip fittings to make an amazing DIY doggy spa.

Ready to push some air through your PVC pipe? Instructables author lewiscreations designed and fabricated an inspiring central vacuum system for their workshop.

Step 4: PVC Safety

Personal Safety

It is important to protect yourself with the correct personal protection equipment when performing certain jobs with PVC.

When cutting PVC, or even sanding PVC, you want to wear safety glasses and a respirator. Plastic chips can severely irritate your eyes if you get any particulate in them, so it's best to protect your eyes when cutting. I know a respirator seems extreme, but the fine PVC dust that is created during sanding, especially mechanical sanding, can be hazardous to your lungs.

Cementing, cleaning, and heat-forming PVC are also good times to wear your respirator. Prolonged exposure to solvent vapors can induce some serious symptoms: stinging eyes, tearing, redness, swelling, and blurred vision. Vapors have a narcotic effect and may cause a headache, fatigue, dizziness and nausea. Getting solvents on your skin may cause redness and pain, which is why I recommend solvent gloves that go past your wrist, but maybe not as high as your elbow.

At very high temperatures, PVC will begin to emit chlorine and dioxins, gross. Prolonged exposure to these chemicals can cause harm. It is important to wear a respirator when heating PVC for bending and forming to work in a well-ventilated area.

Material Safety

Unlike other metal pipes, PVC plastic is very resistant to corrosion over time, but with words like 'vinyl' and 'chlorine' as part of the acronym people often wonder if it is safe to drink water that has passed through PVC pipe.

PVC pipe is safe for water handling jobs that are below 140° F. (My water heater only goes to ~118° F, for reference). If you anticipate higher temperature water, consider working with CPVC (Chlorinated Polyvinyl Chloride). CPVC is much more flexible and can handle temperatures up to 200° F.

PVC pipe is very rigid, but at smaller diameters, the pipe has some elasticity that will allow it to flex and bend. This rigidity can cause flexed material to spring with some force if not properly secured. The PVC pipe wants to be straight, and unless the pipe is heat formed (see Bending Lesson), it will always be flexing toward being a straight pipe again. Once your PVC is flexed make sure it is glued securely into joints or held in place with rebar or fasteners.

Step 5: Designing Your PVC Project

Your PVC project will take some planning. No matter what you are trying to build, I urge you start with a design drawing. Working with PVC fittings is a breeze as long as you incorporate them into your design drawings correctly.

Calculating Distances

When determining distances and pipe length for your project, you'll have to accommodate for the amount of space your joints and fittings will take up along the span of pipe you are creating. The two main values you'll have to consider is overall length and insertion depth.

Overall length refers to the total length of a joint along one connection axis. Insertion depth refers to the distance that the pipe will plunge back into the fitting when making your connection.

I've come up with a formula that helps calculate span distance for segments in joints. This equation helps calculate how many equal segments you need to cut to span the desired length.

Segment length = [Desired length - (total length of fitting x no. of fittings) + (insertion depth x no. of fitting ports)] / desired number of segments

For example, say I have a project that on one side needs to measure 58". I am going to use two 90-degree elbows on the corners and four 3-way tees along that span.

With 1/2" pipe, the total length of the 90° fitting is 1.75" inches with an insertion depth of .75". The total length of the 3-way tee fitting is 2.5", also with an insertion depth of .75" on each hole of the fitting.

The total distance, minus the length of the joints, was 44.5". When you add back the insertion depth, we calculate a length of 52" of pipe that needs to be divided into five equal parts of 10.4" each. Voila! Math is the best!

Going Digital

Sometimes, I will need to build a project with a more complex geometry, and use digital fabrication software to make sure I'm cutting down pipe correctly. My preferred way to work is to use Autodesk Fusion360 and import McMaster-Carr catalog parts inside the app. You can import parts by right-clicking anywhere in your drawing, and then go to Insert>McMaster Carr Part. Fusion360 a powerful 3D modeling platform that's easy to learn and has endless potential.

You can sign up for free as a Hobbyist / Enthusiast / Startup or as a Student or Educator.

  1. Follow one of the links above to download the app (don't use the App Store on Mac).
  2. Enter your email and download the free trial.
  3. Install and setup a free Autodesk ID account. When you open Fusion, select the Trial Counter in the upper toolbar (it tells you how many days are left on your trial). In the next dialog box, select "Register for Free Use".
  4. Sign up as a Start-Up or Enthusiast (Free). You can also Sign up as a Student or Educator (Free) if you're a student or educator at a registered institution. This will give you free use of Fusion 360 for as long as you need it (not just a 30-day trial).
  5. Select the "I accept Terms and Conditions" checkbox and click Submit.

Once you've downloaded the software, check out JON-A-TRON's free class on 3D Printing for some serious tips and learn to use using Fusion 360. (For real, I took the class and have learned so much!).

Formufit also has 3D models of their joints available for download, making it easy to incorporate their parts catalog as well. Before importing them into your design files, you'll have to convert the .skp files into .obj files. This is easy, simply open the part in Fusion360 and then save a duplicate as a .obj file. From there, you can import the .obj file into your larger design drawing.

Step 6: Quiz

{
    "id": "quiz-1",
    "question": "When do you need to wear a respirator?", 
    "answers":[
        {
            "title": "When cementing PVC.",
            "correct": false
        },
        {
            "title": "When heat-forming PVC",
            "correct": false
        },
       {
            "title": "Both.",
            "correct": true
        }

    ],
    "correctNotice": "That's correct, a respirator should be warn whenever you are bringing PVC close to it's melting point or working with heavy solvents.",
    "incorrectNotice": "That's incorrect, try again."
}
{
    "id": "quiz-2",
    "question": "A bushing is inserted into the inner diameter of PVC pipe.", 
"answers":[
        {
            "title": "True.",
            "correct": true
        },
        {
            "title": "False.",
            "correct": true
        }

    ],
    "correctNotice": "That's correct, couplers attach to the outer circumfrence of the pipe.",
    "incorrectNotice": "That's incorrect, try again."
}
{
    "id": "quiz-3",
    "question": "Which diameter of pipe is the most flexible?",
    "answers":[
        {
            "title": "2 inch.",
            "correct": false
        },
        {
            "title": "3/4 inch.",
            "correct": false
        },
        {   "title": "1/2 inch.",
            "correct": true
        }
    ],
    "correctNotice": "That's correct, 1/2 inch pipe is very flexible, making it perfect for pipe-flexing projects like making hoop-houses and shade structures.",
    "incorrectNotice": "That's incorrect, try again."}

Step 7: Let's Cut to It...

Next up, we learn the various ways you can cut down pipe and even machine shapes and holes into pipe.