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PEX cinch or crimp best?

Posted: Sat Jun 12, 2010 7:53 pm
by dinotoad
I plan to redo some plumbing in PEX. I have pretty much decided against using Sharkbites due to long term cost and possible freezing issues. Now I need to decide between cinch or crimp clamps. I thought I had heard that crimp was better but a plumber I talked to says that he now only uses cinch and likes them better.

Which is better, cinch or crimp and why? Freeze protection is my primary concern but I would be interested in other issues like ease of use.

BTW: My contractor says they ran a test freezing PEX and it expanded but never did burst or leak.

Re: PEX cinch or crimp best?

Posted: Sat Jun 12, 2010 8:56 pm
by JD
I have been using PEx cinch clamps about a dozen years and have never had a leak either from installation or afterwards that I know of. Never had a call back on cinch fitting and I give a written guarantee with every job. So I do have complete confidence in the stainless steel system. But I have not heard of anyone having problems with the crimp fittings either. I am talking about stories from actual plumbers or fix-it types. There are stories on the internet about PEx failing, but I tend to believe that is mostly dyed in the wool, copper sweat fitting plumbers stirring mud. I can see where PEx plumbing, using any kind of fittings, is an imaginary threat to plumbers.

So my personal opinion is that both crimp and cinch are excellent plumbing methods. I think the pros and cons are more about application than performance. I like my stainless cinch fittings because #1, they are stainless steel. I was a mobilehome tech for about the last 10 years of the polybutylene plumbing era. The crimp rings kind of creep me.

Also, I only need one crimp tool to do any size fitting, 3/8" to 1". The 1/2 & 3/4 is all I actually use. The bad thing about the cinch fitting and tool is that you must fit the tool square to the fitting. I have closed the tool and went a little sideways on the fitting, causing me to cut the ring off and try again. To my knowledge, there is no small cinch tool for tight places. While this has created challenges, it has never stopped me or even slowed me down much with the plumbing. Just like cpvc, steel and copper, when I am in an area I can't reach in to, I make the hard to reach parts one assembly and put it in as a unit. Another thing I like about the cinch tool is once you get it calibrated right, the tool does this "collapse and click" to let you know when the tool has done it's job right.

With the crimp system, you need different tools for different sizes, unless someone has come up with a multi size tool that I am not aware of. There is the small hand tool to use in tight places, but that crimp is not as accurate as it is with the big crimp tools. It is also important to use the go-no go checking tool with the crimp system. The stainless cinch system does not use them.

The cinch ring is a lot more engineered also. There is a stop built into it so you will know when you are fully seated. You can see the engineering in how the ring actually does "cinch" or tighten evenly around the fitting and you don't end up with the two bumps like on the copper ring.

As for which is best, I am probably no help. I prefer the cinch. Most folks on this forum use crimp. I doubt anyone here will give you stories of PEx failures using either system. It might come down to user preference. I know for myself, when I saw those same rings that we used on PB pipe, I did not have a lot of confidence in the crimps. Back in the PB day, rings often failed right at that crease on the bump. But that was an aluminum ring problem on the old PB pipe. Never had the problem using copper rings on PB pipe.

JMO
JD

Re: PEX cinch or crimp best?

Posted: Sun Jun 13, 2010 12:51 am
by Robert
I agree with JD. I use crimp simply because it is what I learned of first and got and just never saw a reason to change since it worked fine with zero problems.

I've been plumbing almost as long as hvac and was a hard nut to crack also, but once I tried pex, you would get shot trying to make me use cpvc/glue or copper/torches again, LOL.

ONLY if customer insists, but when they see the higher labor cost on those, pex is an easy sell.


One of these days maybe I'll run into someone with the cinch tool and try it out. Maybe. :wink:

With almost 31 years in the trades, these days I work hard at trying not to work harder.


Take care and best wishes,
Robert

Re: PEX cinch or crimp best?

Posted: Sun Jun 13, 2010 8:33 am
by Greg
I use the crimp rings, But for the same reason as both JD & Robert it is what I have used and what I have the tools for. I did buy the pocket crimper from the site here and it does work, but it is much slower than the "regulation" crimp tool but it is also 1/3 the cost. You do need to make sure you use the gauge on it and recheck for leaks after the water is back on. Greg

Re: PEX cinch or crimp best?

Posted: Sat Jun 19, 2010 6:36 pm
by Greg
Just a quick update. I did a water heater job today for a neighbor. Simple job, 30 gal electric for a new 40 gal. 1-2hrs max. YA, RIGHT this turned into a major ass kicking, the old unit had top & bottom cold/hot the new had both on top, no big deal, just add some new tube. After draining & wrestling the old one out of the closet, the dryer blocked me from getting out the door so up & over the dryer (with both the old & new).
Place the new heater in the closet to find the opening was not cut square, 20 1/2" in the middle, 19" at the bottom (the new heater is 20") so we again had to pick up the heater at an angle to get it into the closet.
Almost done, just do the final hook ups & fill. Had to run to the hardware store for the new tubing & fittings. Now here is where the crimp/cinch comes into play. All they had were the push lock shark tooth connectors. OK I've used them before with no problems so I grabbed them. Get all my connections made & fill the new heater. No leaks on the threaded connectors, great!! I look down and the push lock has developed a drip. OK shut off the water, drain the pressure off, take the connector off. I could see no problems with the tube so I re connect it and try again. Still have a drip. SO off to Lowes for the crimp type connector. NO LEAKS!! It only took 4 1/2 hours!!

So I guess my vote is for the crimp type!!! Greg

Re: PEX cinch or crimp best?

Posted: Sun Jun 20, 2010 12:00 am
by Robert
Yep, I know a lot of people use/like the shark push together fittings, but I just don't trust them.

I know my crimps will hold and not leak, so I stay with what has proven itself to me over and over.



Take care and best wishes,
Robert

Re: PEX cinch or crimp best?

Posted: Sun Jun 20, 2010 1:55 am
by JD
Greg wrote:Now here is where the crimp/cinch comes into play
Maybe I am not reading this right but you aren't thinking Sharkbite fittings are cinch fittings are you?

Cinch fittings are rings similar to copper crimp rings, umm only different. But they both work with the same concept.

Sharkbite/Gatorbite fittings are push fittings that work with a neoprene (I think) "O" ring sealing to the outside of the pipe. Those steel teeth you see just keep the pipe from backing up and coming loose.

JD

Re: PEX cinch or crimp best?

Posted: Sun Jun 20, 2010 2:22 am
by Robert
JD, he was saying all they had was sharkbite, he got them and used them and had a leak.


Went and got crimp rings, redone it and no leaks.




Take care and best wishes,
Robert

Re: PEX cinch or crimp best?

Posted: Sun Jun 20, 2010 8:03 am
by Greg
Exactly Robert, I think most of have used the push lock type and had success, but it was just one of those days. I had plenty of 1/2" pex fittings here, but just because I needed a 3/4" luck was not on my side. Greg