# Is pvc primer necessary?



## Birdman (Feb 19, 2008)

For all my koi pond installations I would never make a joint with out it. But have done small 1/2 inch stuff for some of my own projects with out it. Held just fine.


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## Blue Ridge Reef (Feb 10, 2008)

If the pipe is under pressure, I'd use it. And PVC cleaner! For your application, it should be okay. Worst that could happen is a leak, and you have to re-do it later. That's really your call.


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## NeverEndingNinja (Jan 4, 2008)

PVC cleaner helps a lot. PVC is coated in a resin that needs to be removed in order to get a good weld from the glue.

(FYI, I've glued miles of PVC together)


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## RoyalFizbin (Mar 7, 2006)

Thanks for the advice guys but I procrastinated so long last night that I didn't bother starting my project so I went ahead and bought some clear primer today. 

Also, I did a little google research on the subject and it seems there are some people that think that sanding the joints a bit before cementing will work just as well as using primer.


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## JSCOOK (Jan 7, 2008)

RoyalFizbin said:


> Also, I did a little google research on the subject and it seems there are some people that think that sanding the joints a bit before cementing will work just as well as using primer.


Yup that's all I've ever done ... never used primer, just a light sanding to rough up the surface a bit, then cement ... done lots of PVC plumbing and never had a leak yet ... part of the secret is to use enough cement and twist the parts wells to ensure even seal around the connection ...


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## swylie (May 10, 2007)

Unfortunately white PVC looks almost as tacky as white with purple primer. If you're concerned about appearance then I'd paint your setup with Krylon Fusion or vinyl dye.


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## Green Leaf Aquariums (Feb 26, 2007)

They do make clear primer. I use clear on alll of my PVC projects.


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## original kuhli (Nov 28, 2006)

I didn't use it at all and none of my joints have leaked, I did use cleaner though.


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## plantbrain (Dec 15, 2003)

A little pre checking and sanding etc, double coat both sides, use Christy's Red Hot Blue Glue, never had an issue.

One step stuff that works great.

I figure 1200gph and 12 ft of head, and another with 10ft head and 4000gph ought tell if it works.

Other things about leaks: make sure you have no tension between the pre checked fitted parts.

Give the pipe parts some twisting(1/4-1/2 turns etc), use flex PVC tubing (Ribbed, sold at Home depot in 1/2, 3/4, and 1" sizes, perhaps more) where you can to reduce elbows and to reduce tension, pump vibration, use Schedule 80 when you can etc.

If the parts are pricey, like ball valves, unions etc, use threaded parts(you can take these apart later if need be). 

Regards, 
Tom Barr


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