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Reforming PVC pipes
Posted: Sun Jun 07, 2009 4:47 pm
by cocodoc
jimmy101
Read your post on PVC from 09/08. It seems you know a lot about PVC, maybe you can help me. I'm trying to heat 6" PVC pipes enough to reform them and hopefully it will retain that shape when it cools. Do you think putting it in a boiling water bath would accomplish this? Also is there any chance of toxic fumes?
What I am trying to do is make pockets in a 6" PVC pipe all around it to make a strawberry planter. I'm making 5" cuts and want to push the top sie in and pull the bottom out, place a wedge in it, heat it to lose it's rigidity then let it cool and hopefully get hard in the new configuration!
Thanx, MAK (cocodoc)
Posted: Sun Jun 07, 2009 6:11 pm
by rp181
boiling water softens it, enough to bend. What you want to do would need a better heat source.
Posted: Sun Jun 07, 2009 11:02 pm
by mark.f
You can also use dry heat (carefully), but if you have a large seafood or other food boiler that would work.
Re: Reforming PVC pipes
Posted: Sun Jun 07, 2009 11:12 pm
by Technician1002
cocodoc wrote:jimmy101
Read your post on PVC from 09/08. It seems you know a lot about PVC, maybe you can help me. I'm trying to heat 6" PVC pipes enough to reform them and hopefully it will retain that shape when it cools. Do you think putting it in a boiling water bath would accomplish this? Also is there any chance of toxic fumes?
What I am trying to do is make pockets in a 6" PVC pipe all around it to make a strawberry planter. I'm making 5" cuts and want to push the top sie in and pull the bottom out, place a wedge in it, heat it to lose it's rigidity then let it cool and hopefully get hard in the new configuration!
Thanx, MAK (cocodoc)
Take a peek at this page. Heat gently over a torch or gas stove until it softens. Keep it away from the flame as it burns quickly in contact with the flame. I make my own PVC Christmas driveway Candy Canes.
http://www.spudfiles.com/forums/general ... 18336.html
This should work for you. To keep from having to hold hot PVC, a spray bottle of water can be used to quickly cool bent parts so they hold their shape.
Heat it before attempting to bend it. Wedging it cold may break it. When properly heated, it is rubbery like a garden hose. Heat, shape, and cool.
Posted: Mon Jun 08, 2009 11:27 am
by jimmy101
Folks have pretty much anwered the question. Just a couple things to add (i've always got something to add

)
With boiling water there is zero chance of toxic fumes. It takes quite a bit higher temperatures for that. If you use an open flame, like a torch, you can easily get nasty fumes released. Using a torch requires a gentle touch and patience during heating.
Boiling water is just barely hot enough to do small changes in shape with PVC. You need to heat, deform and clamp then let it cool. Usually the PVC will spring back some after the clamps and/or forms are removed so you might have to repeat the process a few times to get what you want.
If your pvc pieces are small enough I would recommend boosting the temperature a bit by using oil instead of water. Use a reliable thermometer and heat the oil up to a bit higher than 212F, perhaps 220 or 230F. The pvc will be more pliable and easier to work but still be too cool to decompose or generate toxic gases. If you are carefull you could even use a kitchen oven.
Posted: Mon Jun 08, 2009 12:03 pm
by Technician1002
jimmy101 wrote:Folks have pretty much anwered the question. Just a couple things to add (i've always got something to add

)
With boiling water there is zero chance of toxic fumes. It takes quite a bit higher temperatures for that. If you use an open flame, like a torch, you can easily get nasty fumes released. Using a torch requires a gentle touch and patience during heating.
A tip on torch or stove heating.. Keep it moving and rotating quickly to avoid a hot spot. Keep it well above the flame. The advantage of torch over an oven is you can monitor the results real time unlike an oven. In bending the candy canes, I heat just to where the area I want to bend turns from a hard rod into a garden hose. It goes limp and flexible. When it does, stop heating, shape and cool. Only a little practice is all that is needed to get the hang of it with no scorch marks or fumes.
Any water or oil dip method heats the end of a pipe. If you wish to keep it round and undistorted for attachment of fittings, this is bad. In torch or stove heating, I heat just the area to be bent and the ends remain cold and perfectly straight. Gloves are not needed to hold and bend candy canes.
Overheating it will toast it golden brown like a marshmallow.
Posted: Mon Jun 08, 2009 12:06 pm
by mark.f
Just piping in, but a heat gun like those used to fix skin over model airplanes can be used as well.
Posted: Mon Jun 08, 2009 12:29 pm
by c11man
i used a heat gun that was very industrialish and it worked very well. it drew 16 amps if that tells you any thing. the heat output was adjustable between 750 and 1000 F. and be careful not to
Technician1002 wrote:toast it golden brown like a marshmallow.
Posted: Mon Jun 08, 2009 12:37 pm
by boom_o_matic_2.0
Technician1002 wrote:Over heating it will toast it golden brown like a marshmallow.
lol dont get me wrong I do love the marshmallow cannon. but every where you look its lurking around somewhere.

Posted: Mon Jun 08, 2009 8:35 pm
by Technician1002
boom_o_matic_2.0 wrote:Technician1002 wrote:Over heating it will toast it golden brown like a marshmallow.
lol dont get me wrong I do love the marshmallow cannon. but every where you look its lurking around somewhere.

You know you are spudder when the mention of toasted marshmallows brings up images of a launcher.
The Dragon Cannon, where I put the bells on the ends of the 6 inch PVC pipe has discoloration from overheating the PVC. I did not mention the marshmallow launcher. I mentioned toasted marshmallows. Note they are not the same.

Posted: Mon Jun 08, 2009 11:11 pm
by maverik94
I would guess that there would be some fumes, you can smell pvc when you're cutting it, so I would guess you would get some fumes.
Posted: Mon Jun 08, 2009 11:12 pm
by maverik94
I would guess that there would be some fumes, you can smell pvc when you're cutting it, so I would guess you would get some fumes.
Fumes
Posted: Tue Jun 09, 2009 12:54 am
by Technician1002
maverik94 wrote:I would guess that there would be some fumes, you can smell pvc when you're cutting it, so I would guess you would get some fumes.
That is why I do it outdoors over the BBQ grill, camp stove, or torch sitting on the ground. I've never been a fan of making bad smells in the kitchen. When it doesn't change color, I have never noticed an odor when bending PVC.