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OK to Mix Metal & Plastic Drain Parts?

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joshh...@fastmail.fm

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Feb 18, 2008, 1:09:46 AM2/18/08
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The plumbing under my kitchen sink has all metal parts. The nut which
connects the waste pipe to the J trap/gooseneck has pretty much come
apart and is leaking. Also, the bottom part of the waste pipe looks
really corroded.

Is it advisable to replace just the waste pipe and trap with PVC
plastic parts, or do I have to replace everything from the bottom of
the sink to where it empties into the main drain pipe in the wall with
either all plastic or all metal to assure a good fit?

Frank

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Feb 18, 2008, 8:39:59 AM2/18/08
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No problem.

aemeijers

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Feb 18, 2008, 9:21:11 AM2/18/08
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That hasn't been my experience with mixing and matching. Gaskets, ring
nuts, tapers, etc, look like they fit, but produce leaks. I usually
leave the pipe coming out of the sink drain as metal if it is in good
shape (Because those are a pita to remove), but switch everything from
there to the threaded fixture in the wall, with plastic, ideally from
the same manufacturer. It's cheap, and I don't ever want to have to mess
with it again.

And like it says on the package, make sure to deburr any end cuts you
have to make on the plastic- burrs attract clogs like mad.

aem sends...

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hal...@aol.com

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Feb 18, 2008, 11:17:50 AM2/18/08
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On Feb 18, 10:54�am, letter...@invalid.com wrote:
> Mixing them is not a problem at all. �However, I will tell you from
> experience. �There the plastic pipe meets the metal threaded stub
> sticking out of the wall, use a METAL ring, not a plastic one. �The
> reason is that the threads on the metal pipes are usually rusted as
> well as being clogged with gunk. �If you tighten the plastic ones they
> strip out their threads. �If you under tighten them, they leak. �Make
> your job easy by buying a metal ring right from the start.

i want to add, had a plumber out once for a persistent leak and now do
what he did every time.

first dry fit everything then mark take apart and
Use the silicone bathtub caulk on all the connections.

jusr smere enough at each fitting to help seal them up, on seal rings
etc.

do it before running water then let silicone dry for a while.

i havent had a single leak since i started doing this.

low cost easy and fast

Frank

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Feb 18, 2008, 12:18:59 PM2/18/08
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I've done them and a couple of different plumbers I've had in over the
years also did them with no problem. Of course you have to be careful
and use common sense.

Frank

sain...@gmail.com

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Jan 8, 2018, 7:10:23 PM1/8/18
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I have had metal drainage pipes under my sink and of course,yes they start corroding...as long as you have a good thread and proper gasketing and you tighten not too much,it will work...just make sure it all fits properly...I'm a packrat when it comes to saving plumbing fixtures....I save all fittings,gaskets,pipe pieces etc....you never know when you need a spare piece down the road.

Tekkie®

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Jan 9, 2018, 4:33:02 PM1/9/18
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sain...@gmail.com posted for all of us...


>
> I have had metal drainage pipes under my sink and of course,yes they start corroding...as long as you have a good thread and proper gasketing and you tighten not too much,it will work...just make sure it all fits properly...I'm a packrat when it comes to saving plumbing fixtures....I save all fittings,gaskets,pipe pieces etc....you never know when you need a spare piece down the road.

Datz nize!

--
Tekkie
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