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.
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.
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Signing UpStep 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.
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.
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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.
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.
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.
If you had a spring the right size then you could use it with heat for bending PVC pipe.
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.
If you want to bend pipe into an exactly repeatable curve, you need something round to bend it around. Ideal would be a shape like a pulley wheel with a channel for the pipe to be pulled into as you wrap it around. That would help reduce flattening on the inside, keeping the pipe cross-section rounder.
You might be able to make such a round pulley wheel shape out of wood, if you have a router to gouge out the channel in the wood. That gets pretty high-tec with the need for tools, though.
The Pipe Viper looks great for bends 30" apart giving leverage to put a bend in PVC. I wonder about bending tight offsets though. A 3" inch offset requires 30 degree bends 6" a part. Add other tight bends in a 10' conduit & you'd have to be superman. It looks like a great tool & I don't understand why the Electrical suppliers haven't pushed it.
Zappenfusen
As far as I can tell, it is just as strong after bending as before. Chemically, I don't think you break any of the polymer chains by softening the plastic, or bending it.
Yes, it seems to be just as springy.
It doesn't become brittle.
Interestingly, it does seem to have some "memory" of its original shape. If you heat it up again, it tends to return to the way it was.
I imagine the original shape was a liquid mass of goo, but the first time it is shaped is as pipe. If you just soften it to stretch it, heat it again and it unstretches.
Someone at the PVC factory told me once that they never have any 2nd quality pipe, because if it is defective, they just reprocess it. From that, I imagine that you can take solidified PVC and melt it again, probably in the absence of oxygen.
You can weld it somehow with a hot air gun and a special tip, but I never had any luck with that.
I don't know the science behind it too, but plastics tend to have a memory of the shape they were in before...
There was a video on youtube that showed someone heating a yoghurt cup in an oven and it returned to the disk like shape they melt to form the cups...
Wikipedia also mentions that it's a thermoplastic.
As I recall, the idea was to stick the PVC pipe up the exhaust pipe and gradually bend it, making the angle appear at the end of the exhaust pipe.
Years ago, I read of some Boy Scout leader who built a little oven around the exhaust pipe. They put food in at the beginning of a trip and it was ready when they arrived. Seems like it would have to be gas tight to avoid contamination of the food. Anyway, it seems like a creative use for exhaust heat.