Mysterious Breaks

A

algerdes

Supporting Member
After years of use, my arches have not changed color (yellowed), have continued to light, and are pretty much forgotten until they are needed. They hang upside down from racks in the storage area. They maintain their shape, even when taken out of their center bracing.

Unfortunately twice now I have had them break in the middle of the arch itself. (One last year, one this.) It is a very clean break - almost like it was a seam in the material. I guess I should be thankful that only two out this group of 16 have done this.

The real interesting part is the breaks happen when absolutely no activity is going on. Both happened with the storage unit closed and no one bothering anything.

Any thoughts as to why they would do this?
 

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Since this is a plumbing material and breaks are far more unacceptable in actual plumbing situations, you might want to ask around in those parts.
 
That is a very good point. After reading this I did contact a plumber friend who stated that he had never heard of one, especially of the size we use, doing this. I'll keep checking.
Thanks again.
 
If I recall correctly, that product is shipped in a big coil, so it is truly unusual that it would break spontaneously..........
 
I'll bet that the outside suffered a nick of some kind either in initial construction or installation, and like plexiglass, the material just split on that "starter" nick.
 
That's what I was thinking. The breaks appear toward the center of the arch and are unusually clean. I have the same arches and were built on Matt Johnson's design in 2014. They have abrasions on them from moving them around and storing them. I hope they are not getting too old, as they have not yellowed either over the years. I store mine right side up on the garage floor.
 
I checked the complete break (on both that I have here and will on the other in the storage room.) There is no sign of even a nick anywhere on the break.

Like said before, this material comes in a coil, is used for delivering fluid in high pressure mode, and should NOT break like this. Where they are stored there is nothing else around them. They hang by their crossbars. Very interesting that there are even this many broken. :blink:
 
I know. But Jim is entitled! :yeah:
BTW, the whole display is 12vdc. The last 5vdc props were converted last year.
 
OK. We had a third one split last week. They are sitting in my driveway, in an enclosed trailer. Temps here have been all over the map, but this is normal here. These things have lasted many-a-year. :(

I need to know if anyone has a source for 2" white, in stock. I believe it is HDPE, but not sure of that anymore. We have decided to rebuild the broken ones, and create a few spares (just in case). Heck, it has been so long since we built these that I don't have a clue as to where to get the tubes today. Coils are preferred over sticks. We have bases and crossbars. May have to order some strips (10/30, 12vdc, WS2811) as well.
 
Al,
McMaster Carr https://www.mcmaster.com/ldpe-tubing/

I have included two screen shots. The 50375K64 number is what I ordered in 2015. Sorry this happened to you. Good Luck. Be sure to call them about the shipping prices before ordering so that you don't get a shock.
Keith
 

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Yes, shipping is a 'B'. As I recall, one of our members that lives in Washington State did a group buy which helped defray the high shipping costs. He split it up in 10' lengths and sent it on to each member of the group buy. I think most folks drove to his place and picked it up.
That stuff still shouldn't have split with that little use.....
 
Thanks folks.

BTW - rstehle, these are NOT the ones that came down the mountain. :rolleyes: These are the original, 2" pipes I have had since the beginning.
What we refer to as the "Colorado Arches" are wider, I'm thinking 2.5", and haven't had any problems other than some of the strips going on vacation. No biggy.
 
Most PE pipe is designed for underground usage. I wonder if this is UV degradation from being used above ground for several seasons. Sounds like the same clean breaks i get in the older pixel strip material.
I've got several arches of the same material and vintage as yours and haven't had any breakage yet. But mine have yellowed a bit, not really noticeable on its own, but when i put it side by side with new material that's been inside, then it stands out.
 
Interesting thoughts Jon.

I need to temper that with the fact that for 10 months of the year they are in a 55 foot long shipping convex, hanging upside down (by the crossbar holding them together), and in the back where no light is found unless someone opens the doors. For 9 of those months, the only ones going in or out (and allowing the "sun to shine in") are PJ and me, and then for only a few moments and a few times.

The stresses on any pipe in the ground include ground movement, which one would think would cause problems. These don't have any of that.

I guess this whole thing falls into the category, "Things that make you go, hmmmmmmm."
 
You said you store them upside down, so the curve or the top of the arch, is hanging at the bottom, when stored, correct?

I'm not sure, but being stored in a storage unit with extremes in temps from summer to winter in your location, I bet the heating and cooling has caused the tubing to repeatedly expand and contract, and all that stress was focused on the top of the arch where it was hanging down, and she eventually broke when it was VERY cold and brittle.

It's not a flaw in manufacturing, not when it happens in the same spot over and over, nor is it UV, because it's a clean break in half and UV would be more of a crack, not a clean break in two. That almost has to be from stress being focused on to one point and that's where it is hanging at its lowest.
 
PEX Couplers were looked at. (Thanks for the suggestion.) The extra density at the coupler makes it look like a dark section, even though lights are under them. One interesting suggestion that has some merit and will be tried as a test, is the use of some "melding" glue. It actually causes the PEX to join like PVC cleaner & glue "melts" the PVC to create an unbreakable bond. That will be attempted next spring.

For now, we have turned the broken parts into some "interesting" props. As far as the remaining good ones, they have been augmented by additional arches given by someone who no longer uses them (he changed to the Boscoyo Arches - and loves them) so our display will have the numbers that we need.

FYI - we went through all the arches and did "maintenance". All strips were tested and several were in need of repair/replace. While doing so - we removed the bracing and each of them didn't move much from their "held position." (They mostly kept their shape.) We are taking this as a sign that the amount of stress on the tubes isn't as much as we thought. Also, all arches are subjected to the same conditions. Why just some? We may never know.
 
We made HDPE pipe where I use to work. For HDPE, you can heat up the ends and fuse them together. The weld can be stronger than the pipe. For just a few joints, you could heat up a metal plate instead of using a pancake iron in the video below. Ideal melt Temp is ~350F.
https://youtu.be/20MdDIzYwao

-Craig
 
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