Introduction: Bend PVC Pipe

Picture of Bend PVC Pipe

PVC pipe is a great material for making things.  If you ever need to bend the pipe, here's how to do it.

The trick is to fill it with sand before heating the plastic and bending it.   Normally, the pipe would pinch closed in areas where it is bent, but the sand prevents that.  When the heat forming is finished, you just drain out the sand. 

Step 1: Safety While Heating PVC

Picture of 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: Fill the Pipe With Sand

Picture of Fill the Pipe With Sand

Cover one end of the pipe with masking tape to hold the sand in.   Fill the pipe with sand, tapping the taped end of the pipe on the ground to compact the sand inside.  When the pipe is full of compacted sand, tape over the top end.  You are ready to heat and bend.

Step 3: Heating and Bending

Picture of Heating and Bending

I use a gas stove for heating and bending sections of pipe. 

Hold the pipe from both ends.  Keep the pipe moving back and forth over the flame, rotating the pipe all the while so that the area to be bent is evenly heated. 

Keep the pipe at a reasonable distance from the flame to keep from burning it.  Heat penetrates slowly through the plastic.  Be patient.  Haste can result in burnt plastic.  Don't try to heat it too fast.

When the plastic softens up some, the pipe begins to sag from its own weight and the weight of the sand inside it.  It gets leathery.

At this point, turn off the stove and bend the pipe into the shape you want.  Do it on the floor, if you want to keep it all in one plane. 

Step 4: Some Finished Shapes

Picture of Some Finished Shapes

These are a few bent pieces of pipe.  The ends of the pipe are still taped. 


AndrewKFletcher made it! (author)2017-10-16

Used a 22mm plumbers pipe bending spring in 25mm mdpe water pipe. Worked out well.

harryclark (author)2017-07-06

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JakeP70 (author)2017-03-31

Do you think if u had a vase i was wraping the pipe around i could instead have a empty tube and use a heat gun to blow heated air into it vs using a stove. The heat gun was used for shrink wrap which im not sure if its going to be hot enough for bending the pvc pipe

Thinkenstein (author)JakeP702017-04-03

Try it.

ibertion (author)2014-06-04

sorry, is it really necesary to use sand? isn't it possible with any other type of ground?

Thinkenstein (author)ibertion2014-06-04

Sawdust works. Dirt might work, if it stays loose and doesn't compact too much into a hard mass.

I think I would try that before the sand.
I have filled metal tubes with sand and did not like the results. The give of sawdust may work better even were it packed some in the tubes I bent.

mitchells365 (author)ibertion2015-09-18

Dry Dirt would probably work, I wouldn't use sawdust though as it could start on fire, making the possibilty of a PVC chemical fire more likely, which is bad for you and the environment. Anything powdery/dusty and Inert should work. (I.E. Doesn't Burn, and can take a lot of heat)

craig.kling.9 (author)2016-03-26

For a thing to burn, Chlorine is a more reactive oxidizer than oxygen.
I do not know what might be produced from PVC that may burn in absence of air. I don't even know any list of things that can be oxidizer.
I think I read that hydrogen and chlorine will just explode - or burn - to produce HCL in same manner that oxygen and hydrogen can be burned to produce H2O.
Just thought I'd throw that in .....

pillageTHENburn (author)2013-12-12

A few people have asked if you can do this without a stove. YES! But this might not be what you were thinking:
I have done this with GREAT success using sand and a toaster oven. I put the sand on a tray in the oven and heated it to about 212˚-280˚F, then quickly and carefully (with a funnel) pour the sand into a capped piece of pvc. At this point I just held the pipe vertically with one hand (at the open end) and sort of "wiggled" it back and forth until it began acting like a cooked noodle. Pretty soon it's soft and bendy and you can do what you like with it! The sand keeps it from collapsing and provides the heat. I was consistently bending 2" radius curves with no problems!

On a different note you have a quote that says " does not need oxygen to burn so don't do this inside". I find that hard to believe since fire is an oxidation reaction and you can not have fire without an oxidizer (oxygen). 6th grade teaches you the three things needed for combustion: heat, fuel and oxygen. So I don't see how it could "burn" without oxygen. Am I missing something chemically here?

lovekatz (author)pillageTHENburn2016-01-19

A sand tray in the oven? I know a race car driver who bent an entire acrylic windshield that way, but his girlfriend married him anyway!

The chemical decomposition of some chemicals creates oxygen, which helps to burn the resulting hydrocarbons. It's kind of like the experiment in science class were you burn wood to produce methane, capture it and then burn it also. This also makes burning wood more efficient. The problem is that the smoke produced tends to get in the way of external oxygen, which stops the flame from igniting and burning the methane. PVC is actually fire retardant though so I don't where the author got that from. Like the other commenter said, it is definitely possible because underwater fireworks burn with no additional oxygen.

mderusha (author)pillageTHENburn2014-12-03

the burning material provides its own oxygen. that's how things burn under water.

lovekatz (author)2016-01-19

opeyumi: maybe you could use a can filled with sand? make the bend in your sand-filled pipe, cut off the ends with a tiny overlap; smooth them till they will just meet; empty the sand; gently warm your pipe on a flat bed of sand to get it in a single plane

lovekatz (author)2016-01-19

How about using a hair dryer?

opeyemi.seun2 (author)2016-01-15

Please I need to make my pvc pipe a full circular bend and I don't know how to go about it any idea will be appreciated

When jewellers make split rings, they bend a wire around a round dowel like a long spring and then cut through one side of the spring to make a lot of split rings.

You might be able to do the same with 1/2 inch pipe filled with sand and then wrapped around a larger piece of pipe. With luck, the split rings could then be forced, with heat if necessary, to have their ends together and held somehow. I'm just guessing. I have never done that. Good luck.

singhainish (author)2015-08-30

Thumbs Up. ( wish there is an icon here for thumbs up )

maveric__fil (author)2012-11-21

Epic instructable! i never would have thought you would have to put SAND in it. Thanks!

07reisdaydar (author)2012-07-18

Thanks for the instructable, i will use this to make the sump return for my marine tank!

AntMan232 (author)2010-06-19

I don't like to put a damper on things, but as far as i know, when you heat PVC you get chlorine gas, which is poisonous. I just thought i'd let you know, but its probably too late...!

jack8559 (author)AntMan2322012-05-03

I'm not sure, but pvc may also give off cyanide gas when overheated. I'm sure that many plastics do give off this gas and it is a very real danger to inhale it. Any super glue that contains cyanoacrylate will certainly give off cyanide gas when burned and many plastics manufacturing processes include stuff like this in their products. PLEASE be careful when heating plastics and always have a lot of ventilation - use a fan if you have one even outside, no need to take chances with your life over a piece of plastic!

Thinkenstein (author)jack85592012-05-03

Check it out, if you are not sure, and let us know. Poly-Vinyl-Chloride doesn't sound like cyanide to me.

I agree that there are no known health benefits to breathing burning plastic. The art, not a difficult one to learn, is to not burn the plastic when you soften it. Yes, good ventilation is always important.

yellowcatt (author)AntMan2322012-04-14

You would need a lot of direct heat to form toxic gas, I have bent lots of PVC with no problems at all. The bending temperature is about 100 to150°C and it takes a temperature of about 390°C or more to char PVC.

If forced to burn PVC will not produce chlorine but will emit dense acrid fumes containing noxious and toxic compounds including carbon monoxide, hydrogen chloride and possibly dioxins.
However PVC will not burn on its own, it needs continuous applied heat to char it.

Thinkenstein (author)AntMan2322010-06-19

Well, I know how chlorine smells and I have never smelled chlorine while heat forming PVC. Of course that is below burning temperature. If you burn PVC, yes, you get some nasty fumes. The fumes don't smell like chlorine to me, but they probably contain chlorine. With fumes that smell so bad, I never hang around to analyze the aroma in detail. Anyway, and I swear I'm not lying, I'm still alive!

AntMan232 (author)Thinkenstein2010-06-20

If you insist, i'm a bit doubtful about the last comment, but i'd better take your word for it!

MichelMoermans (author)2010-01-15

Your 'ible made me think. In highschool we never used heat to bend pvc pipes, for our installations we used something that you could just stick into the pipe and then bend it using your own force. Then when you were done you'd simply pull it out and the pipe would remain undamaged but bent in a nice curve. I think I have one of those things lieing in my garage. I'll check tonight and see if my memory isn't betraying me...

If it works like I remember I'll post a picture and maybe make an 'ible of my own about it.

I imagine you are thinking of another material.  If you bend PVC cold, it tends to spring back into its original shape. 

Anyway, whatever you remember seems new to me, and I'd like to know what it is. 

godofal (author)Thinkenstein2010-01-15

no, i know what hes talking about, and hes right.
its like a long spring, one of those pull versions, it fits really nice inside, and it doesnt require alot of force!

MichelMoermans (author)godofal2010-01-15

Yep, that's right. It's some sort of a spring.

I asked my dad about it and he says that it works with all "normal" PVC pipe of normal diameter.

Just stick the spring in there and bend using your hands. I can't find the spring in the garage right now but if I can't find it in the morning I'll search for a picture on google :)

There ya go, it was quickly found. This is what we used in school. A spring that bends the pvc pipe cold without compromising the integrity or durability of the pvc pipe also the spring is the same diameter as the innerhole so while bending the hole won't get smaller.

This video explains how it works and how less time consuming it is.

I never would have believed it possible, but I saw the video.  Pipe Viper.  I'm going to have to send for one of those.  Thanks.

You're welcome :)

According to me it has been around for atleast 4-5 years since I came in to contact with it when I was 14.

That's why it suprised me nobody here seemed to realize you could bend pvc cold. Well this is were instructables is for gaining knowledge and using it to fit your needs  :D

how does it work?

This video should give you a pretty clear picture.

But it's just sticking the spring in. Look were you want to bend your pipe. And bend it with your hands until you have the shape you want. Then you just pull the spring out and your done :D It does require the use of some force but if a 14 year old can handle it I'm pretty sure everyone here can too.

I mean, what are the mechanics of it?

yellowcatt (author)Sandisk1duo2012-04-14

The spring supports the pipe wall and prevents it buckling.
I have bending springs for copper pipe but had not realised that it would work for PVC pipe without heat.

looks alot like a weakened version of a garage door spring

Arbitror (author)MichelMoermans2010-01-15

The Pipe Viper is a pretty amazing concept!

Funk_D (author)2010-01-21

This is awesome! Just this morning I was trying to think of a way to bend some PCV I have to make a bike rack so I didn't have to go buy 90 degree joints! Thank you!

Also, do you think this method would work with copper piping? I need to bend some into a radiator shape but I can't figure out how.

yellowcatt (author)Funk_D2012-04-14

Copper pipe can be bent cold using a bending spring. These are only three or four pounds each but you do need the right size for the pipe.
If you had a spring the right size then you could use it with heat for bending PVC pipe.

Thinkenstein (author)Funk_D2010-01-21

I think copper pipe has been bent cold with sand inside.  Pack it tight and give it a try. 

crashrandall (author)Funk_D2010-01-21

 If you get ductile copper tubing, it is bendable without heat.  The straight stuff is not so bendy though, and is prone to cracking and creasing instead of bending clean.

jcksparr0w (author)2012-03-29

to improve this instructable, you can also heat you PVC with a heat gun(used in art for embossing paper or other materials). Much less chance of fire, much safer, and works about as well. Good idea to post this though.

Thinkenstein (author)jcksparr0w2012-03-29

A heat gun is fine. Not everybody has a heat gun, though. Propane torches and gas stoves are more common.

You can play with fire and not get burned. You just have to be careful. Keep work moving to avoid hot spots, and at an appropriate distance from the flame.

yutzwagon (author)2010-06-21

This looks pretty cool. I wanted to make a boffer kukri, so I think this should work well. Thanks a lot!

Thinkenstein (author)yutzwagon2010-06-21

You're welcome. Apparently, a kukri is a curved knife. I don't understand the reasoning behind shaping a knife like that. If I recall correctly, boffers used to be sort of foam swords people could boff each other with, without hurting each other. If I was crossing a boffer with a kukri, I'm not sure what I would get. So how does bending PVC pipe work into making a boffer kukri?

asda1246 (author)Thinkenstein2012-02-21

the drop in a kukri's blade is to help chopping power and there has been stories of Gurkha kukri's chopping a man from skull to pelvis in a single stroke

Thinkenstein (author)asda12462012-02-22

I'll keep that in mind next time I have a similar task.

mli3 (author)Thinkenstein2011-08-09

I think a Kukri is more of an axe hatchet knife combo. The curved edge makes it easier to cut.

About This Instructable




Bio: I'm a refugee from Los Angeles, living in backwoods Puerto Rico for about 35 years now and loving it. I built my own home ... More »
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