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bending plastic pipe????

Discussion in 'Chit-Chat' started by maninblack, May 14, 2008.

  1. maninblack

    maninblack Guest

    hi all
    anybody know how to bend plastic pipe its about 23mm dia..
    many thx
  2. Hi,

    I have done plastic tube/pipe bending using a bit of heat to assist, depending on the plastic of course and what type of bend you need.

    I would say with the diameter tubing/piping you are looking at you should be able to find a plumbers spring to fit inside that (same sort as they use for metal tubing) and bend it to the angle you need whilst heating the tube/pipe. Have a look in B&Q as they sell such things in the plumbing dept. Insert into your tube/pipe and then heat and bend it as it warms up. The spring will maintain the roundness of the tube/pipe as it bends.

    Once cooled enough you can pull the spring out easily and the tube/pipe will be spot on.



    GEEDUBBYA Scale Model Member

    Howdy MIB, Mark,

    Well short of buying a spring, heres a little trick I have often used at work when bending conduit, copper or aluminum tubing without a bender an any sort other than a vise. This should work well on plastic tubing while applying the heat.
    Tape off one end of the tubing securely, fill the tubing with a fine sand (salt will work), then seal the other end of the tubing like before.
    Heat with a hair dryer the area you want to bend (we use a torch for conduit, copper or aluminum tubing), making sure not to actually liquify the plastic, as the plastic softens, bend the tubing as desired, the sand/salt filling will keep the tubing from collapsing at the bend point (meaning the tubing will retain its round shape).
    Once you have reached the desired shape, allow to cool, remove the tape and pour out the salt or sand and cut to length.
    One other note, if you use salt or something like sugar, even if this material becomes embedded in the heated plastic, a warm water rinse will remove any embedded "filler".
    This method is also great around the house for little "plumbing projects" for sinks, toilets ect.

    i hope this helps,

  4. maninblack

    maninblack Guest


    cheers lads
    bought a spring but it was to small even though it stated it was right!!
    so will have a go with the sand
    thx again

    GEEDUBBYA Scale Model Member

    Howdy Mick,

    Let us know how it worked for you, like I said this method is great on metal tubing and is a neat trick to know.

    Have a good day,

  6. peter22

    peter22 Scale Model Member

    I agree with previous - only comments
    1) plastic is a poor conductor of heat take time to allow heat to permeate thro' tube wall and warm the sand
    2) plug end with a tapered plug bit of broom shank, fill with dry sand compact by tapping lightly with a hammer shaft then plug firmly with rag.
    3)the smaller the radius bend the more difficult - the back stretches/thins, the throat compresses/ripples
    4)the heat will travel along tube - cool with cold water/rags to prevent it bending past your mark.
    5) try to bend around a former paint tin shaped wood etc.
    6) bend just past required angle then pull back to get the bore true
    best of luck peter22
  7. maninblack

    maninblack Guest

    kin plastic!!

    hi lads
    tryed the sand method still creased the pipe!!***
    also bought anothersring still no good
    the pipe is 25mm AAAARRRRRRRRRGGGGGGG!!!!!
  8. peter22

    peter22 Scale Model Member

    What is the wall thickness of tube and the angle of bend + the radius?
    Do you know the type of plastic?
    and i'll have another think [I was a lecturer in building services teaching Plumbing - and i've bent using sand before sucessfully but 20? years ago!!
  9. maninblack

    maninblack Guest

    sorted another way

    hi lads
    finally got it sorted...
    gave up on the bending lark , got fed up buying conduit! LOL!!
    fitted the water straightners with elbows to the out lets
    crude but works great(tested in the bath)
    will see if can put pics later
    many, many thx to those who replied:respect1:


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