# Pvc cement glob inside pipe



## psider25 (May 4, 2020)

I have been installing a ton of 1 inch cl200 pvc for my irrigation system ... about 1100 ft so far.

The pvc cement seems to keep globbing up inside the fittings in very thin layers almost like it is scraping a thin sheet off the pipe when I push it in.

Method: prime both sides, glue female end liberally, glue male end sparsely, push pipe in rotate half turn.

Any ideas of the cause ....medium body pvc cement is what I am using.

Is this going to ruin my valves? Here's a pic of a extreme one, most aren't this bad.


----------



## hsvtoolfool (Jul 23, 2018)

Wow! I have never seen anything like that! That's not "glue" in the pipe. The cement is a solvent and you "weld" the pieces together. But in your case, the outer CPVC layer softens and bunches up in the joint when it's pressed together. That's just crazy.

I don't think it matters too much for irrigation, but are you using correct "CPVC" glue or do you have "PVC" glue? Acetone is the active solvent in both types, but maybe that's a factor.

If you have the correct type CPVC glue, you're not waiting way too long to push the parts together, and you don't have a bad batch of CPVC, then I suggest using less glue. I like to barely see a bead of cement squeeze-out after I press the joint together and twist. I never slop the solvent around everywhere because it literally melts (and weakens) the plastic. So you might try using less glue inside the female fittings and leave the last 1/4" or so without glue. You don't want cement inside the pipe.

Finally, you may try skipping the primer since this is irrigation and building code won't require it. I found this article rather interesting....

https://www.plumbingsupply.com/the-great-pvc-primer-debate.html


----------



## psider25 (May 4, 2020)

Here is the cement I used. I am switching to oatly fusion tonight.


----------



## Gilley11 (Nov 3, 2019)

Looks like you may be letting the pieces sit too long before actually putting them together. Maybe you could try putting them together more quickly. It won't ruin your valves but it will obviously restrict water flow to some degree.


----------



## hsvtoolfool (Jul 23, 2018)

If that plastic "buildup" in the pipe is thin and fragile, then it will break loose and likely collect in the valves. It won't damage them, but it may jam it open or closed. If that happens, you just need open up the valve and pick out the debris. I installed a stainless 100-mesh filter in-line just before my manifold to keep such debris out of my valves....

https://www.sprinklerwarehouse.com/1-in-clear-stainless-steel-filter-vfnt100-100ssp


----------



## RVAGuy (Jul 27, 2020)

I just did an install. It's from not chamfering the male pipe. It scrapes the inside of the female fitting, where the primer makes it soft. If the male end were chamfered at a 45, it wouldn't happen. I realized it when I started, but didn't bother fixing it. It'll be fine.

A pro carwash guy (my buddy that helped me) NEVER chamfers PVC and they use smaller nozzles with no problems. I've also read around and professionals don't bother either. Don't sweat it. If it really bothers you, you can pick it out with a right-angle pick when it's still soft. After it hardens, it's not going anywhere.

Source: Step 1 here: https://oateyassetcdn.azureedge.net/assets/Document/raw_01_Solvent Cements_PRODINSTRUCT_001.pdf


----------



## hsvtoolfool (Jul 23, 2018)

That's interesting. I have never chamfered PVC or seen a plumber chamfer PVC before glueing.


----------



## RVAGuy (Jul 27, 2020)

Agreed, it's not done in industry, and if someone is installing a sprinkler system, I'd bet house they don't chamfer edges. It just takes too much time. It's tough even finding the tools to do so.


----------

