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PVC cement questions and freezing temps

WillieWonka's picture

Does anyone know if PVC cement in the can will freeze in freezing temps and if so does it ruin the cement or will warming it up make it work good as new?


Also, when working outside in very cold temps, does this affect the ability of PVC cement to make the same good strong joints it otherwise makes?


Also, sometimes if I open a can of semi-aged PVC cement it's sorts jelly-like, where the dauber webs the cement as you pull it out of the can. Is jelly-like PVC cement useless or still usable? I've also had well aged PVC cement be nothing but a blob of heavy jelly in the can, my natural inclinations were that it's totally bad then, no way of salvaging it, so I toss it. So I'm more concerned about the semi-prejellying I've seen in asking this question.


Lastly, in a pinch, can the gray conduit PVC cement  be used to glue PVC drain fittings, in other words, is it really the same stuff, different color? I been in a bind before where ran out of PVC cement but had some gray conduit cement, but didn't use it due to not being sure it'd work as well or not.


If at first you don't succeed, try using a hammer next time...everything needs some extra persuasion from time to time.  -ME
If at first you don't succeed, try using a hammer next time...everything needs some extra persuasion from time to time.  -ME

(post #68977, reply #1 of 5)

Willie:


PVC cement is basically PVC plastic dissolved in solvents.  The joint works by FIRST making the mating parts SOFT and swollen using the PRIMER.  The cement then bonds the two swollen layers of PVC material together, filling any gaps and taking up the space when the parts shrink again once the solvent evaporates.  You can see why the primer is an essential step and cannot be skipped!  I've seen lots of piping pop apart under pressure when someone skips this step, though some does hold for a time.  Using the purple dyed primer is a good way to demonstrate that you've done this important step.


Will PVC cement freeze?  Well, sort of.  Though the solvents themselves have very low freezing points, the dissolved PVC may come out of solution a bit, producing a layer of free solvent on top of the PVC cement.  Unless this gets mixed back in, you're going to lose that solvent rapidly.  But since making up the joint is a dissolution/swelling process, there is a minimum recommended temperature for doing these joints and you must not apply PVC cement below that temperature.


PVC cement that has "hardened" has merely lost solvent.  There's no irreversible "curing" going on.  Cement that's gone a little thick and stringy can be thinned down again by adding primer, which is basically just a solvent mixture with no PVC dissolved in it.  Stir it and let it sit for a couple of days- if you get a thin glue mixture again, you're fine.  If it's dried out too much and won't re-dissolve after a couple days, throw it out as it may take heat to get the PVC to redissolve- and those solvents are enormously flammable so heating is a very scary business indeed.


Can you use conduit glue for water pipe?  Both are PVC so yes, you'll get a joint out of it.  Will it be up to the strength of the piping?  Probably, no reason that it shouldn't that I can think of, but if it were in my house I wouldn't risk it.  If the piping is for potable water, stay away from the conduit cement as it may have constituents in it which are not safe for potable water.


If it's CPVC (chlorinated polyvinylchloride), you need a special cement and primer.  There are CPVC cements which are also permitted for use on PVC pipe, but not vice versa.

(post #68977, reply #3 of 5)

Take a look at http://householproducts.nlm.nih.gov/cgi-bin/household/brands?...  Use pvc cement and pvc primer to search


Looks like the solvent mix is different in the primer  and the cement. You may recover the cement with the primer as a solvent, but it may not be as effective as a new can.


The stuff is cheap enough that using a gelled or nearly gelled can isn't worth the risk to me. I hate call backs, particularly when I know I cut a corner. I purchase new cement for each project in a size that won't leave a lot left over. Leave what is left open to air dry out, and toss it out when it becomes solid.


BTW cure time increases below 40 degrees F and with pipe size according to the label on most cans. Handle accordingly.


 


Dave

(post #68977, reply #2 of 5)

have used "all weather" PVC glue for conduit , and we try to keep the can as warm as possibe by taking it into the trailer during break and the stuff works below freezing ... it is also clear instead of gray

edit for:
I have no idea if it is good for plumbing,
I have used primer on conduit (but it is not required ), as it is for plumbing...
try thinning the thickened glue you have with some primer


Edited 11/14/2005 8:13 am by maddog3

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(post #68977, reply #4 of 5)

You don't say which PVC cement you are using, thick, thin, or hot (sometimes labeled in the big box store as thick, medium, & thin).


The hot mix is very thin, and can be used to "thin" thicker varieties of PVC cement--though, it's almost as simple to just get cases of smaller cans in my book.


The thinnest mix is good for when it's cold out, or for when you are building a "tree" (manifold) in PVC.  The thick stuff is nice for when you have to reach up through an arm-sized hole, and get the glue to "stick" to a joint pointing straight down, without getting glue all over everywhere.  Or where it's going to tak a couple of seconds to get the parts from glue to joined.


I'd not reccomend using conduit glue on potatable water supplies, jsut because I'd hate to cope with any problems down the road.  The glue mix is supposed to be exactly the same, but that's a one heck of a bet to make with potable plumbing.


Also, many plumbing inspectors look for the distinctive color of primer, as "proof" that you are doing a legit job.  If your glue is purple, you might have to explain why (or be watched carefully using primer first on all joints, then cement, then joining with the correct twist and all. 


Occupational hazard of my occupation not being around (sorry Bubba)
I may not be able to help you Occupational hazard of my occupation not being around (sorry Bubba)

(post #68977, reply #5 of 5)

There is a low-temp PVC cement formulation, available in most stores. 


The regular stuff takes a very long time to set up in cold weather.  If you provide a little gentle localized heat you can get a quick set on a cold day.


They also sell a "slow set" formula, which is marketed for assembling PVC shower pans and enclosures.  This is good if you need some extra wet time, like for assembling PVC trim.


I do not think that PVC cement is spoiled by freezing water temps, since the freezing point of the cement is -139 degrees farenheit.


Gorilla PVC cement is good to 32 degrees F, because it has a water base, though that stuff is always slow to set.