Ask Me Help Desk

Ask Me Help Desk (https://www.askmehelpdesk.com/forum.php)
-   Plumbing (https://www.askmehelpdesk.com/forumdisplay.php?f=259)
-   -   CPVC adhesive... what to use? (https://www.askmehelpdesk.com/showthread.php?t=55402)

  • Jan 17, 2007, 01:35 PM
    mtnbkr
    CPVC adhesive... what to use?
    The subject states exactly what I want to know... what type of adhesive is best for connecting CPVC? Should I use a all in one (primer/adhesive) or a 2 part (seperate primer and separate adhesive)? Thanks!
  • Jan 17, 2007, 01:48 PM
    RickJ
    I've never used the primer/adhesive combo - and am a bit leery of using it especially since neither the primer nor the glue is expensive. I go the safe route and use the separate products.
  • Jan 17, 2007, 06:53 PM
    speedball1
    Quote:

    Originally Posted by mtnbkr
    The subject states exactly what I want to know...what type of adhesive is best for connecting CPVC? Should I use a all in one (primer/adhesive) or a 2 part (seperate primer and seperate adhesive)? Thanks!

    Perhaps if you're a dentist you can use a "all in one primer and glue" (Google it) when you work on teeth but plumbers use primer and CPVC Cement when they work with plastic pipes. You have to realize what primer's used for on plastic pipes. It's used to take the "shine" off the pipe and rough up the surface so the glue will bond better. Sandpaper would do just as well. If you combined primer with PVC cement it would dilute the glue which is why it isn't done.
    Regards Tom
  • Jan 18, 2007, 04:55 AM
    mtnbkr
    Many of the CPVC cements that I've seen are "one-step." Is that what I want to use, along with a separate primer, specifically designed for CPVC?
  • Jan 19, 2007, 07:41 AM
    speedball1
    Quote:

    Originally Posted by mtnbkr
    Many of the CPVC cements that I've seen are "one-step." Is that what I want to use, along with a seperate primer, specifically designed for CPVC?

    CPVC solvent cement should always be for CPVC piping and manufactured to meet the requirements of ATM F 493. Purple primer manufactured for PVC pipe is acceptable. Faster flashing CPVC primer is available, and is recommended for cold weather installations. Orange CPVC solvent cement and purple primer are specifically required by certain code bodies to facilitate identification by plumbing inspectors. Unpigmented CPVC solvent cement and primers are available and are acceptable in various jurisdictions. Clear cement/primer provides neater finished appearance. One-step cements are now available and are fully satisfactory if the manufacturer's instructions are carefully followed. Your local plumbing inspector can provide a final answer to this question.

    It would appear I'm mistaken and one step solvents came on the market after I retired. My apologies! When I Googled One step solvents it took me to dental cement. However, I still prefer separate primer and cement for plastic pipe and fittings. Regards, Tom
  • Jan 22, 2007, 11:44 AM
    mtnbkr
    Quote:

    Originally Posted by speedball1
    CPVC solvent cement should always be for CPVC piping and manufactured to meet the requirements of ATM F 493. Purple primer manufactured for PVC pipe is acceptable. Faster flashing CPVC primer is available, and is recommended for cold weather installations. Orange CPVC solvent cement and purple primer are specifically required by certain code bodies to facilitate identification by plumbing inspectors. Unpigmented CPVC solvent cement and primers are available and are acceptable in various jurisdictions. Clear cement/primer provides neater finished appearance. One-step cements are now available and are fully satisfactory if the manufacturer's instructions are carefully followed. Your local plumbing inspector can provide a final answer to this question.

    It would appear I'm mistaken and one step solvents came on the market after I retired. My apologies! When I Googled One step solvents it took me to dental cement. However,. I still prefer separate primer and cement for plastic pipe and fittings. Regards, Tom

    I got some purple primer that says it can be used for both. Should I use this for my CPVC and my PVC connections? Should I go and look for the orange stuff since it sounds like it might be better? As for using it, do I just brush the primer on, then immediately brush the cement on? Do I wait for something to dry first? Thanks.
  • Jan 22, 2007, 12:07 PM
    speedball1
    You have to realize what primer's used for on plastic pipes. It's used to take the "shine" off the pipe and rough up the surface so the glue will bond better. Sandpaper would do just as well.
    Use the purple primer, brush it on, it will dry in a instant. I would'nt let let any dirt get on the primed surface but once it's been primed you can glue the fitting anytime. Good luck, Tom
  • Jan 22, 2007, 12:15 PM
    mtnbkr
    Thanks! You must be talented... not only speedy, but knowledgeable too!
  • Sep 10, 2009, 11:56 AM
    mikneygrahm
    The purpose of the primer given by speedball1 is not correct. I've used cPVC for many years. I'm also an engineer.

    The primer is used to pre-soften the cPVC plastic. The glue or cement is really not a glue at all. Doesn't work by gluing,it works by welding. It is a "solvent Weld". That means the cement actually returns the surface of the cPVC back to a liquid. The two pieces literally mix their molecules together and then set back to a solid.

    For cPVC you MUST use cPVC cement because the first "C" means the PVC has been chlorinated. Regular PVC cement will draw the chlorine and weaken the pipe or whatever, especially at higher temperatures.

    The PRIMER is a very low viscousity(thin) liquid used to penetrate the plastic. It is true that often as the surface is softened you can take a rag and "Clean" the surface. As you wipe, some of the plastic will wipe off and along with it some dirt.

    The cement itself (usually orange in color) is more viscous and stays put on the surface longer, and its solvent evaporates more slowly. But it does not penetrate the plastic as deeply as the primer does. So, first you soften the plastic with PRIMER then coat with CEMENT(pieces can still be wet with primer). Coat both the male and the female(often called the "bell").

    The "shine" of the plastic does not matter because you are not glueing.

    Even though the cement may be still wet after one minute or so after welding, the joint will have achieved about 85% of its strength.

    So, to answer your question about 1 part vs 2 part solvent welding. The one part solution compromises both the primer and the cement phases. It will work but not as well.
  • Sep 10, 2009, 01:06 PM
    speedball1
    When you're right you're right! Mickey piggbacked on a 2 year old thread but he's right and I was wrong. I was always taught it was the glaze that you wanted off the plastic. Although I've always used primer on PVC I used it for the wrong reason.
    Thanks for setting things straight Mickey. Tom
  • Dec 10, 2011, 08:47 PM
    luke316j
    So glad I had the same question and for the people on here thank u for not getting mad and nasty with each other instead we learned a little bit lol :)
  • Dec 11, 2011, 07:57 AM
    speedball1
    Hi Luke and welcome to the Plumbing pageat at AskMeHelpDesk.com. You piggybacked on an a 4 year old dead thread. In the future, before you post, look in the upper left hand corner for the date.
    Glad you're question got answered, Stop in any time. Tom
  • Nov 23, 2012, 12:36 AM
    apgupta
    Mr. Grahm, you have answered it precisely. Can you please suggest what is the formulation of CPVC adhesive.
  • Nov 23, 2012, 09:20 AM
    speedball1
    Why would you want the formula for CPVC? Do you plan on brewing some up to save a buck? I guess you'd have to contact the factory for that informjtion.
    Good luck, Tom
  • Nov 23, 2012, 11:27 AM
    massplumber2008
    I'm afraid Mr Grahm won't be returning to answer your question as he only posted once in 2009 (see above).

    The MSDS sheet is the best we can do, apgupta

    Check it out @:

    http://www.herchem.com/msds/MSDS61_CPVC_cem.pdf

    Mark

  • All times are GMT -7. The time now is 07:50 AM.