Attn: Plumbers
 

As some of you know, I am a HVAC/R service contractor. During my course of service, I occasionally use CPVC piping for condensate drains. What I have experienced is, that almost every time I open a can of CPVC cement, use it once, only to find when the next time I use it, it is either thickened or gelled up.
I have tried several procedures and techniques to keep the cement good but have come to the conclusion, once you open a can, it is a one time deal. I limit the "air exposure" to an absolute minimum and the results seems to be always the same.

Is there something that can be done to preserve this cement or is this the nature of the beast....?? :Huh:

You can try injecting a gas into it, I shoot argon from my welding tank into my paint hardener just before capping it for the day, and it keeps it from going bad.
The last ppg hardener I used last summer, was a 6 year old quart and it was good and not a solid chunk of useless solids like if no inert gas was added.
They sell a small shot can @ good paint suppliers. (I think it is nitrogen but would have to check)
I think the trick is to keep air/oxygen out of it.
You can try propane as it is heavier than air and it would displace the air/oxy that enters the can, and you have propane torch handy.
worth a try--:beerchug:
Disclaimer:
I have not tried it on cpvc see-ment :biggrin2:

I may be way off base here but many brands "Oatey" included, contain Acetone. I believe the Acetone evaporates, causing the cement to turn to jelly. Freezing could also play a part in the jelling process, but my bucket of plumbing tools normally lives in the basement where it doesn't freeze and many brands will turn to jelly anyway.

I have started using "Black Swan" brand "3 way cement" (there is no Acetone listed on the label). The can that I have here is probably 2 years old and gets used occasionally, it still looks good today.

I have considered adding a little Acetone to cans of other brands that have jelled, just to see if it would come back to normal, but who has time for such nonsense?

But yes you're right, open a can of Oatey, finish the job and throw the rest away...

I make sure I use a channel lock pliers to tighten the cap,works for me.

acetone is the answer...youre right... it evaporates very fast....squirt a little in there and stir it up...only thing ive seen evaporate faster is methyl chloride

That does seem to be the nature of the beast of PVC glue. George's idea may be the best. FWIW, I too like Lew, put the cap on real tight. Actually helps if you use the glue to "glue" the cap on. You have to use pliers to open it back up, but seems to increase the shelf life. I usually buy the smallest can possible unless I'm doing a big job. Usually my can is still good for a few months. Seems that extreme temps make it worse. If kept in a conditioned space seems to help also.

Or, you could just buy a new can for every job and bill them for it. :biggrin2:

There used to be that a very small can was sold but not now i have grease the threads and left the can upside down .
But in a yr its toast

My approach: Any container with a hammer on or screw on lid/cap, cover the opening with cling wrap, put on the lid/cap, store in a zip-lock bag. Works most of the time.