# Help: Bonding Polypropylene with PVC Pipe



## prp427 (Jun 28, 2011)

Would you recommend plastic cement or pvc primer and cement to bond the two? 

I am trying to build a cerges reactor and the inside tube is pvc connecting to a polypropylene filter cap. 

I only have one shot and don't want to mess it up. :help:

Thanks!


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## nayr (Jan 18, 2014)

the multipurpose pvc cement should work just fine, its inside the housing so leaking is no concern.. you just want to hold it in place so it dont fall out right? its sticking to the PP that is the problem, could sand it lightly to give better adhesion.

actually bonding the two would require an epoxy I suspect.. Polypropylene is practically impermeable and hard to bond anything with.

Gorilla Glue might work, its basically liquid polypropylene and would expand to give a good fit.. it wont create a watertight seal, but it should hold em together if you rough up the plastics.. forming a nice friction fitting.


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## Dead2fall (Jun 4, 2014)

Silicone. 

Or just buy a tube you have to stuff in there. There's no pressure behind it so it'll stay in there. Makes it easier to pull out and clean too. The eheim 534 tubing fit my filter housing head like it was made to be jammed in there.


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## prp427 (Jun 28, 2011)

I would assume that I would need a air tight seal. Since co2 bubbles will be churning right next to the joint, any bubbles getting through would defeat the purpose of the cerges reactor.

I have a pvc coupling that fits pretty snug. I have read a suggestion to boil the pvc and ram it in there. Would that process seal it?


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## Dead2fall (Jun 4, 2014)

Don't worry too much about an airtight seal. As long as you have something jammed in there with no gaps it'll be OK. Mine puts out 0 bubbles and it's just tubing jammed in there.


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## prp427 (Jun 28, 2011)

Okay, thanks I'll try that. I might put a thin bead of silicone too just for safe measure.


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## Dead2fall (Jun 4, 2014)

Like I said, then it's a pain to pull the dip tube out if/when it's time to clean it


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