How long should glue dry?

salt lick · #1 12/24/2006, 10:12 PM

I'm modifying the plumbing to my skimmer and UV unit. I use lots of true unions, but some of the plumbing passes through the floor so I have to glue a couple of fittings in-line (as a repair).

I want to minimize the down time on my skimmer and #2 circulation (surge tank) pump. How long should I wait before turning pumps back on after gluing PVC? I'm using Weld-On 795, made for flex PVC. concern is toxicity and lack of skimming. After glue drys I can soak the fitting in some DI water to help leach out any volatiles.

Any experience would be appreciated.

lovethereefer · #2 12/24/2006, 11:12 PM

I normally just use the standard PVC glue for the flex and let it sit about 30 minutes before I run water through it if I really need it

salt lick · #3 12/24/2006, 11:44 PM

standard glue works on spa-flex PVC but is not as reliable (too brittle).
the 795 remains flexible after curing, so the local strain of the glue matches the pipe.

lllosingit · #4 12/25/2006, 09:25 PM

Quote:

Originally posted by salt lick
standard glue works on spa-flex PVC but is not as reliable (too brittle).
the 795 remains flexible after curing, so the local strain of the glue matches the pipe.

I've always used standard pvc glue for flex-spa hose, It's recomended even. It's not a glue but a bonding agent.
Sorry I don't have an answer for using weld-on I don't recall anyone using it for that purpose. I would go with the recomended drying time on the container.

hllywd · #5 12/26/2006, 08:55 AM

Can't tell you about the Weld-On but Oatley PVC cement is considered cured at 2 hrs at 60F or above (and ready for 180 psi)per the instructions, longer below 60F.

Why would it matter if another cement allowed the pipe to remain flexible? What situation would allow the cement to be outside a rigid fitting where flexibility would be an issue?

Tim

salt lick · #6 12/27/2006, 08:16 PM

Thanks for the input,
But you all are missing my question. I know how long the glue takes to dry (full strength), but that does not mean that solvents are not still evaporating or leaching out. Anyone have a toxic reaction experience from not waiting long enough? When I originally plumbed the system I waited several hours to dry, then flushed with fresh water for several days.

Tim: I use regular PVC cement for rigid pipe, and the flex solvent for flex pipe. I you never move the flex PVC pipe after installing it then it does nor matter. If the the flex pipe moves for maintenance or in service then you should use the weld-on 795.

hllywd · #7 12/27/2006, 08:45 PM

Since PVC can be used in potable systems and the can says 2 hours that's when it should be safe (or Oatley could be in for big trouble). I'd let it go over night and use it. There should be no reason to rinse, certainly not for "days" (again the whole liability thing).

Tim

dkh0331 · #8 12/28/2006, 06:20 AM

I've used the Oatley for my flex pvc and ran water thru it at 2 hours with no effects at all.

lllosingit · #9 12/28/2006, 10:06 AM

Quote:

Originally posted by salt lick

Tim: I use regular PVC cement for rigid pipe, and the flex solvent for flex pipe. I you never move the flex PVC pipe after installing it then it does nor matter. If the the flex pipe moves for maintenance or in service then you should use the weld-on 795.

Regular PVC cement isn't really a cement it's a bonding agent, It causes a chemical reaction to weld the joint together.
It can be moved twisted flexed and it will not come apart.
As far as dry time, I put joints together and it's been used it within minutes with no problems. There was a post where a guy knocked the whole open can of glue into the tank and it landed upside down on the sand bed , He never lost a single fish or coral.

Weldon might be a different story, I've never used it except after letting the joint dry at least overnight.

H20ENG · #10 12/28/2006, 10:45 AM

Hi Salt Lick, good to see you here again.
I've glued stuff up and restarted after 20 minutes or so with no ill effects. If you dont use an excess amount of glue, leaving puddles in the plumbing (which also compromises its strength in "real", high pressure plumbing situations) and wipe the joint clean if possible, it will dry quickly.
You can also use wet-r-dry glue which kicks off real fast, but its an ugly blue color. I wouldnt go near that beautiful carbon fiber tank with ugly blue glue!!

Just keep your skimmer running strong and maybe some fresh carbon if your worried.
Chris

salt lick · #11 01/02/2007, 10:25 PM

Chris,
thanks much, thats exactly the kind of real world advice I was looking for.

Bobwan

H20ENG · #12 01/03/2007, 11:58 AM

Sure thing, Good luck