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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Danny on April 28, 2007, 08:59:58 PM

Title: plumbing questions - pex
Post by: Danny on April 28, 2007, 08:59:58 PM
I am into the plumbing pretty good now.  I got some pex from Lowe's and it was very rigid.  They said there was a more flexable kind but it was only available to plumbers.  Any ideas as to where a person could get this pex?

Thanks,
Danny
Title: Re: plumbing questions - pex
Post by: boogiethecat on April 28, 2007, 10:25:15 PM
The Rigid stuff is the good stuff.  Just use a few additional fittings to get around corners etc.  I've done two busses with the Rigid stuff now, they were both extremely easy & fast to plumb, not a single leak except when I forgot to crimp an otiker clamp :) and the stuff is great for hot, cold, and freezing.  The stiffness
really isn't a problem when you get in to doing it.

Have fun
Title: Re: plumbing questions - pex
Post by: RTS/Daytona on April 29, 2007, 04:27:24 AM
the more BENDABLE PEX tubing is called   FLEXPEX

see--> http://www.pexconnection.com/products.php?catID=61
Title: Re: plumbing questions - pex
Post by: Dallas on April 29, 2007, 04:37:19 AM
The neat thing about the rigid PEX is that if you kink it you don't have to cut out the kink and splice in a new piece.

You can heat it with a torch (be Very, Very Careful) or a paint removal heat gun and straighten it back out without losing the structural integrety of the original.

I'm not sure if you can do that with Flex-Pex or not, but it's a handy option if you make a really stupid mistake like I did  :-[ umm, I mean a friend of a feller that I am not aquainted with did!
Title: Re: plumbing questions - pex
Post by: belfert on April 29, 2007, 05:27:56 AM
I have a piece of Flex-Pex I bought to repair the plumbing in my old travel trailer.  (I did not buy it for extra flex.)  It really is not that much more flexible than the other stuff I bought at Home Depot when I did the bus plumbing.  I would not call it extremely flexible as Pex Connection does.

Brian Elfert
Title: Re: plumbing questions - pex
Post by: Kristinsgrandpa on April 29, 2007, 07:40:58 AM
Pex is freeze proof but, when the fittings freeze they expand the crimps and start leaking when they thaw out.
   If you're going to leave it unheated in cold weather blow out the lines or use RV antifreeze.

Ed 
Title: Re: plumbing questions - pex
Post by: Skykingrob on April 29, 2007, 06:53:25 PM
Hi Bryan
That is a very interesting observation that is different that my experience. My local Lowes handles both in side by side displays. The flexable type is very flexable where the roll pex is very rigid. Wonder if maybe a a different brand than yours. Killer with using this stuff is the $100 for the tool. Anyone out there have the tool for sale at reasonable amount or rent?

Rob
91 Lemirage XL
Missouri
Title: Re: plumbing questions - pex
Post by: belfert on April 29, 2007, 07:15:22 PM
I looked at the Flexpex I have again.  It is more flexible than I remember.  I would say it is about twice as flexible as the Zurn PEX piping I bought at Home Depot.  The Flexpex is close to three times the cost of the Zurn Pex, at least around here.

I used Oetiker stainless steel stepless clamps instead of the special PEX crimp bands.  The Oetiker tool is $20 or so on Ebay and the size 17 clamps are around $20 for 100 on Ebay.  I didn't use an entire bag of 100 on my bus, but I also had 10 or 20 left over from my travel trailer.

I choose the Oetiker clamps because Jayco used them on my previous travel trailer and I already had the tool from fixing a plumbing problem of my own making on the travel trailer.
Title: Re: plumbing questions - pex
Post by: Hartley on April 29, 2007, 07:51:32 PM
On the tools deal,

Check your local Pawn shop or used tool guy.

The 1/2 & 3/4 inch Electrical Cable Terminal crimpers are the same size as the expensive pex branded tools.

I bought a set for $15.00 at a pawn shop and they at the time had 6 pairs all priced differently,
I dove into the misc tool bucket and found them in there. The nice part is that they all have very long handles
and makes it easy to do crimps without straining yourself.

8)
Title: Re: plumbing questions - pex
Post by: belfert on April 29, 2007, 08:13:28 PM
I'm not sure I would trust cable crimpers for this.  There are very tight specs that need to be met for the crimps.  They even have a special plate to measure each crimp to be sure the crimp is correct.

Title: Re: plumbing questions - pex
Post by: Danny on April 29, 2007, 09:14:27 PM
The guy at Lowes said I could use a mechanical clamp - like the heater hose in a car...  Any thoughts?

Danny
Title: Re: plumbing questions - pex
Post by: Hartley on April 29, 2007, 11:56:23 PM
Quote from: belfert on April 29, 2007, 08:13:28 PM
I'm not sure I would trust cable crimpers for this.  There are very tight specs that need to be met for the crimps.  They even have a special plate to measure each crimp to be sure the crimp is correct.



I compared the pawn shop crimpers to the ones that Home Depot sells and the crimp heads were identical in every way
right down to the interlocking alignment dimple. The difference was the handles. Same Jaws just longer handles. I also measured
with a micrometer, same !

I haven't had a single leak or even a pull-out and I tried on any of the 150 or so crimps that I have done.

I guess that there may be different ones out there so some may be different. Mine are adjustable and just happened to work
without doing anything. They just don't fit into cramped spaces.
Title: Re: plumbing questions - pex
Post by: NewbeeMC9 on April 30, 2007, 01:54:43 AM
I used the compresion fittings,  little more costly per fitting but no tool needed.  i can take a joint apart ang reasemmble with same fitting. Trick is to not bottom out before you tighten the fitting.  I also use some of the push type fittings.  Easy to assemble.  Havent had to diassmble yet.
Title: Re: plumbing questions - pex
Post by: belfert on April 30, 2007, 05:43:35 AM
Quote from: Danny on April 29, 2007, 09:14:27 PM
The guy at Lowes said I could use a mechanical clamp - like the heater hose in a car...  Any thoughts?

PEX is a lot less flexible than most heater hose.  I doubt that hose clamps would work all that well.

I also suspect hose clamps would cost more than the proper clamps, but not really sure.

Brian Elfert
Title: Re: plumbing questions - pex
Post by: boogiethecat on April 30, 2007, 06:50:35 AM
Danny, no.  Hose clamps won't apply anywhere NEAR the pressure needed to create a leakproof connection.  Not even close. That's probably why that guy works at Lowes, he couldn't make his plumbing leakproof  in the real world!

As far as tolerance of crimpers, I made my own crimper for otiker clamps, out of an old AMP crimp tool.  There was no spec available so I just ground the jaws of the tool by eye until it seemed to work, and have had absolutely no leaks at all after 100 or so clamps crimped.  Some of the crimps came out crooked when the tool broke and I didn't catch it... some were too tight, some may have been too loose but over 5 years not not a leak.  Given that i'd say that the crimp tolerance is pretty broad and it's not critical in any way, as long as it's tight enough.  Nothing wrong with doing it right and to spec, but my experience says you can be sloppy and it's also fine.
Title: Re: plumbing questions - pex
Post by: skipn on April 30, 2007, 06:57:23 AM
   I've used hose clamps to fix breaks on the road. I lightly warmed up the PEX with a propane torch before tightening. 6 years and still holding.

   There are different levels of compression fitting.
     Plastic compression- has worked fairly well for me.
     Brass compression with a brass hose insert that gets a tighter fit. I use in high stress area.

 FWIW

  Skip