PVC -- It's Great for Inventions





Introduction: PVC -- It's Great for Inventions

PVC, polyvinyl chloride, is a thermoplastic. It softens with heat and rigidifies when it cools again. While soft, it can be bent and even stretched into molds. Cold, it can be sawed, filed, drilled, scraped, or whittled with a knife.

PVC material can be found at most hardware stores in the form of plumbing pipe. I find it to be inexpensive, especially when I consider all the things that can be done with it -- musical instruments, repairs, tools and toys to name a few.

It is resistant to sunlight damage, has a degree of flexibility, is fairly strong, and is electrically non-conductive.

This is a very valuable material for use in inventions; one that very few people seem to be have experience with.

The picture below shows some of the shapes it is possible to make with PVC.

Step 1: Safety While Heating PVC

We love plastics for what they do for us, but plastic manufacture and decay tend to pollute the environment and negatively affect our health.

Vinyl Chloride, one of the components of PVC, is carcinogenic. When it is locked up in the polymer, however, it is much safer to be around. In my years of experience working with PVC, I have not noticed any adverse effects on my health from being around it.

Always work in areas with good ventilation. If you do get caught in a cloud of smoke, hold your breath and move to clean air.

When heating PVC with a gas stove or propane torch, try not to let it burn. Smoke from burning PVC is bad. With experience one burns it less and less. Don't panic the first time you do burn some. It scorches, but doesn't immediately burst into flame. Move the material away from the flame and try again. Don't breathe the smoke. Smoke avoidance comes naturally for most people.

While heating PVC over a gas flame, keep the plastic an appropriate distance from the flame to avoid scorching the surface before the inside can warm up. It takes time for heat to travel to the center of the material being heated.

Keep the plastic moving, and keep an eye on the state of the plastic. When heated, the PVC material is flexible, like leather. Beyond this stage, you risk scorching it.

A word from James, the plastic engineer -- "Just a word of warning, PVC can handle some high heats but if it catches fire, you wont be able to put it out, it does not need oxygen to burn so don't do this inside".

I do work inside, but my house is made of cement and has good ventilation. MAKE SURE THAT YOU HAVE GOOD VENTILATION. PLAY WITH FIRE -- CAREFULLY.

Step 2: Using Lacquer Thinner to Remove Lettering

Inventions look nicer without stray lettering on them.

When pipe leaves the factory, it is printed with information about the pipe. Fortunately, a little lacquer thinner and a piece of toilet paper will usually remove the lettering, or most of it.

Lacquer thinner vapors are not good to breathe. Make sure you have good ventilation. Only a small amount of thinner is needed to wet the wad of toilet paper. I poked a small hole in the plug under the cap when I bought the new can, instead of removing the whole plug. That way, I only get the thinner I need, and release the minimum amount of vapors into the air.

Step 3: Flattening PVC

To make a flat sheet of PVC to work with, cut a section of pipe and cut the pipe section down one side. Hold it with pliers and heat it over a gas stove.

When the plastic heats up, it will unroll itself and feel like a piece of leather. Place it on the floor and put a piece of plywood, or some other flat object on top of it until it cools. When it cools, it rigidifies again, and you have a flat sheet to work with.

Use a gas stove to heat large areas. Use a propane torch to heat small areas.

The photo below shows a narrow strip of pipe being flattened.

Step 4: Bending PVC

In the dust pan shown below, the square body was folded from a flat pattern.

The handle was formed by hand, pressing the heated plastic around a piece of pipe. Protect your hands from hot plastic by using rags.

To speed the hardening of hot plastic, you can cool it quickly with water. I sometimes hold projects under a faucet, use a spray bottle, or sponge them with a wet sponge.

Step 5: Using Molds

A mold is a shape that is used to create another shape. In the case of the toilet paper roll holder shown below, the hole at the end of the central pipe served as the "female" part of the mold. The ball of a ball peen hammer served as the "male" part of the mold. Between the two of them, they forced the flat plastic into a domed shape. When the PVC cooled, it hardened again.

The dome locks into the end of the pipe section upon which the roll of toilet paper spins.

Step 6: Example: Scissors Handles

Separate instructables could be done for each of the objects shown here. My goal here is to give you a broad overview of what you can do and to inspire you to invent whatever it is you need.

My fingers didn't fit in the handles of these tiny sewing scissors. I solved the problem by making larger handles and attaching them to the smaller handles. Just fold over the plastic and press hard until it cools.

Step 7: Example: Cup Holder

These are two cup holders mounted near my computer desk. It is nice to avoid spilling liquids onto the computer keyboard.

Step 8: Examples: in the Kitchen

PVC has solved a lot of problems for me in the kitchen. Move your cursor around the picture to get the details.

Step 9: Examples: Handles

PVC is smooth, and fits comfortably in the hand. It is great for making handles for things. Just heat the end of the pipe, jam it over what is left of the old handle and squeeze tightly until the plastic cools.

Step 10: Example: Fruit Pickers

A friend gave me a light weight fiberglass sailboat mast, which makes a great picking pole. I made an adapter for the end so I could use it with different fruit picker heads.

One has gardening shears mounted on the end. Pulling strings open and closes the jaws. I can cut small branches with it.

The other pole uses a two pole system to open and close a pair of scissors. I use it to snip the stems of fruit.

Step 11: Examples: Mixed

This is a collection of left over odds and ends.

I think that when the inventors in the Instructables community start playing with this material more there will be an explosion of new ideas.

"Necessity is the mother of invention." See what you need and try to make it.



  • Trash to Treasure

    Trash to Treasure
  • Pocket-Sized Contest

    Pocket-Sized Contest
  • Paper Contest 2018

    Paper Contest 2018

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A word from James, the plastic engineer -- "Just a word of warning, PVC can handle some high heats but if it catches fire, you wont be able to put it out, it does not need oxygen to burn so don't do this inside".

Um wrong Jimmy. I've been able to extinguish burning PVC by dunking it in a tub of water!

Just a quick question, I have an old twin cassette deck boom box which is run by the plastic wheels with the teeth on them and not by belt like they used to be in the past before my system came in to production in 1988. Some of the teeth have come off of the wheels where they have become so brittle and fragile over the years and need replacing for my system to work properly again, I will need to make the wheels as I can not replace them, Philips, the manufacturer of the system no longer have the model listed on their system so they can not give any info either. I have spare sheets of UPVC from cuttings that are the same thickness as the wheels so rather than place any danger of poisoning, pollution or fire, rather than trying to melt it in to molds of the wheels will it be better to make the molds, use Ally or another kind of mettle to make the wheels and then once they cool properly use them as guides to cut the wheels from the UPVC instead? It will take a lot longer but would this be the better and safest idea?

Hi Ian,

You are out of my ballpark here, but I would be tempted to shape the wheel directly, maybe carving the teeth with an x-acto knife into the edge of the wheels. Maybe you could drill the center hole, run a bolt through it as a shaft for a drill press chuck and file the wheel as it spins, to center the circle, and then sharpen up the knife as much as possible for the detail cutting of the teeth. Probably would take more time than it is worth, and might not work, at that.

Good luck with whatever you try.

I have a few questions. I want to melt pvc pipe into solid bar 2" x 2"

My idea is to place the pvc pipe into a 1 1/2 inch x 6 foot galvanized steel pipe (aka fence pole) then dig a 6 foot trench, suspend the pipe over a fire in the trench and melt the pvc down.

(I plan on filling both ends of the galvanized with tin foil balls so that none of the pvc material leaks out.)

How long should I keep the pipes over the flames so that I have completely melted the pvc inside so that its evenly melted and there are no air bubbles etc?

Will it complicate the melting process if I slide a small pvc pipe into a larger one and melt both at the same time to achieve a thicker solid stock?

you can do this with hdpe which is a different type of plastic than pvc and its found everywhere for instance milk jugs, detergent bottles, shampoo bottles and pretty much any plastic bottle in your house. anyways it is much safer and less toxic to melt than pvc and i have had lots of luck melting it into boards and plastic lumber in a toaster oven. make sure you have a mold such as one made out of wood that you can clamp under pressure as the plastic melts down to the consistency of taffy which requires pressure. and always melt it in a toaster oven rather than a fire as melting it in a fire will burn and ruin the plastic and may smell bad.

You contemplate an experiment that I would not perform. I have no experience melting PVC, but I doubt it would get runny without first catching fire, especially if the escaping gasses are close to the flame. I imagine that, industrially, the viscous material is pumped into molds under pressure. You would probably be interested in this link. www.preciousplastic.com

what about pouring melted pvc on the back of solar cells to encapsulate them ?

Sounds pretty toxic, risky, and potentially damaging to the solar cells. It might not even melt to pouring consistency.

Take a 12 inch piece of 1 inch diameter PVC, stuff it with C-4, a put a blasting cap on one or both ends.