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I'm cementing some schedule 40 PVC pipe using the best instructions I could find ( http://www.tchristy.net/pdf/ChristysTechManual_v5_English.pdf ). The outside of each joint looks fine, but inside there's often a mess of plastic scrapings, PVC primer and PVC cement:

PVC Pipe Cement inside junction at stop

PVC Sprinkler Pipe

The dross could clearly affect water flow or clog a filter. I won't use PVC pipe for drinking water because of lead (See http://chej.org/2013/09/pvc-pipes-bringing-toxic-lead-to-drinking-water/ ), but for those that do, the bits of plastic in the water could be an issue.

I've already tried rotating less while inserting, but that's not always practical. I'm cutting pipe with a ratcheting PVC cutter and deburring with sandpaper.

How can I get better looking interior joints?

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Did you deburr the pipe after cutting it? How did you cut the pipe? –  Tester101 May 15 at 20:27
    
Answers above. The cutter is a big box special: a miserable tool not worth the low price. The cuts are clean though not particularly square. –  Bryce May 15 at 20:57
    
If you can get a miter saw to where you're working, that'd be good. –  Edwin May 15 at 21:13
2  
It appears the primer is overly softening the fitting plastic. Apply primer to the pipe first and use only enough of both primer and cement to fully cover the mating surfaces. Try to work quickly once the primer is applied. –  bcworkz May 15 at 22:22
    
The purple primer/solvent instructions state they want a thick coat, no holidays, go over it twice. I'll try less solvent. Post primer I'm at 30 seconds before the joint is done. –  Bryce May 15 at 23:50

2 Answers 2

That level of glop is not normal.

Some things to check:

  1. Is the pipe end deburred? A file plus sandpaper to finish works well.
  2. Are the pipe & fittings dry? Water can do strange things to PVC cement.
  3. Be firm, but don't push too hard, and don't over rotate. 1/8 of a rotation is enough.
  4. Work quickly, but do let any residual drips in the primer evaporate before moving on to glue.
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Never having seen this I can only assume you were pushing WAY to hard and turning it caused a boring action in the softened plastic. Otherwise you fell victim to substandard fittings; a Home Depot specialty. –  Mazura 2 days ago

I think your largest problem is too-thick (old, perhaps?) cement... although I've never seen such a nasty glop inside any PVC (or CPVC) pipe joint of any size.

Nobody seems to have asked whether you ream, as well as deburr, your pipe before glueing... but I cannot think that failure to ream would cause a problem like this.

You're using real "PVC cement" from the store, and not something somebody whipped up in their basement, based upon acetone? Your buildup looks to my eye like the solvent in your batch is far too active, and is melting the pipe very aggressively. Could I get you to try another fresh can from the store?

I'm not sure what passes as "primer" where you are, but primer here is more a cleaning agent than anything else; the cement does all the work of bonding the pipe to the fitting. I saw, give it a quick swipe of primer, let the primer dry, apply cement, and immediately join pipe to fitting - straight insertion followed by about 1/4-turn. By the end of the 1/4-turn, the cement has always set up tight - and I barely have enough time to align (where alignment is necessary) my fitting with my Sharpie mark on the pipe. Peeking in through a coupling, all that can be seen is the reamed end of the pipe with a very small bead of cement around its rim.

You might find it handy to use a coarse-toothed hacksaw blade (in a hacksaw) to cut PVC pipe.

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The cement was brand new. Eventually with some practice I was able to make good joints. Early joints I think I rotated the pipe too much while it was all wet. –  Bryce Aug 21 at 5:33
    
You MIGHT have been applying glue too early, too; it looks like there's a lot of still-sopping-wet primer inside that coupling. Primer isn't part of the chemistry that makes the joint, and too much may actually interfere with the cement. You ARE applying cement to both the pipe AND the fitting, correct? You don't need much more than enough to get it completely wet. –  TDHofstetter Aug 21 at 5:54

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