pex tubing

[Steve Gase]

There are discussions around pex tubing, and I'd like to get more info about it -- benefits and trade-offs.


I've not used it before, I had assumed that it was the same as the rigid, thin-walled PVC we use as SSC enclosures, but there were enough comments that I wondered if I had it right.


I've looked online and find that the vendors show plastic, rolled tubing as pex.  It is used for heating and plumbing.


Since my frame of reference is the 200 PSI PVC pipe, I'll use it for comparison in my questions...


First things that come to mind:

• is it more or less expensive compared to the pvc pipe?
• are the walls more or less thick compared to the thin-walled pvc pipe?
• are the wall more or less translucent than the pvc-pipe? (does more light pass through?)
• what are the advantages over the (rigid) pvc-pipe?
• what are the benefits?
• what are the trade-offs?

As I imagine putting it along the roof-line I imagine the material to be difficult to train to look straight.
I imagine using it for arches and it seems that it would be too floppy.

[chrisatpsu]

   is it more or less expensive compared to the pvc pipe?
less expensive

   are the walls more or less thick compared to the thin-walled pvc pipe?
thinner than thinwall (people use it for the water pipes in their home, it have to bend around corners and stuff)

   are the wall more or less translucent than the pvc-pipe?
when using smart strips (fro wiki) thinwall pvc lit up the tube more evenly, pex, you could see more spots of light.

   what are the advantages over the rigid pvd-pipe?
rigid, like sch40? it's thicker, and can barely light it up at all..

   what are the benefits?


   what are the trade-offs?
in long lengths, pex can start to get too flexible, and flimsy

[jnealand]

I have also been looking at Pex.  Here are the prices at my local home depot a week ago. The blue and white are the same price.  Lowes wanted something like $87 for 1" pex.

[MrChristmas2000]

If your arches or other elements require lengths greater than 10ft I would recommend against using PEX pipe.

I needed 11.5 ft for my arches and bought a 100ft roll of PEX pipe early last summer. Thought if I straightened it out that it would relax in the summer heat and be easy to work with. WRONG. Even after putting straight tubing inside the PEX all summer when I pulled it out it did not take long before it tried to return to it's original rolled shape. Even when I applied heat directly to the pipe it still would not relax. I tried installing several of them as arches and they flexed just every which way. It looked terrible.

I switched over to 1" thinwall PVC from Lowes (a friend used some from Home Depot that wasn't as translucent). They looked great this year. They even stood up to fairly strong winds without any guy wires. I had other elements blow around but the Arches stayed put.

The PEX pipe would be excellent for some small walkway arches because they are very translucent and seem to be easier to work with in the smaller lengths.

[jnealand]

You can buy pex in straight 10ft lengths at both Home Depot and Lowes in my area, but only in a max of 3/4 in.  Prices was about $5 per stick.

[chrisatpsu]

so then..  i was wrong... the thinwall pvc is cheaper per foot. (by about 10cents/ft)

[Steve Gase]

Yep, at Lowes I can get 100' for $22.50

[smeighan]

I have also been looking at Pex.  Here are the prices at my local home depot a week ago. The blue and white are the same price.  Lowes wanted something like $87 for 1" pex.

I bought the 100' of 1" PEX in white. I laid it out for a week and it was better, but it till wanted to curl to its original shape.

I drove 1/2" rebar at a 20 degree angle leaving 2' out. I slid the pex ove the pipe, That worked fine. I then cable tied my rgb pixels to the arch. I tied a guy wire to the middle of teh arch to stop it from curling. That worked fine. My arches were 14' long, maybe 6' high.

Thin wall pvc is not carried at home depot or the lowes near my home.

[JonB256]

How easy would it be to cut a PEX tube in half (lengthwise)?  Would it walk too much?
Not the stuff off of a roll, but the 10ft tubes (though cut into shorter lengths).

I made lighted window frames with dumb RGB flex strips and they are a little too bright.
I suppose I could dim them in software, but I think a half-tube of PEX covering would both Dim and Diffuse them to look better.

I have a small table saw and could try it. Just wondering if anyone has done it already.

[doubleeaz]

I just did a test last night on PEX with one of the RGB strips from ebay.  It was the 300 LEDs/5 meters kind.  There is also a 150 LEDs/5 meter.  I used 1/2" PEX and 3/4" PEX from Lowes.  I found that the 1/2" PEX showed the individual LEDs much more than the 3/4".  Also, 1/2" was pretty dark on the bottom of the LED strip where the 3/4" was much more even.  I bought the 5 foot straight pieces for testing but will most likely buy the 10 ft straight pieces.

Have not tried thin wall PVC.

[rogerwh]

How easy would it be to cut a PEX tube in half (lengthwise)?  Would it walk too much?
Not the stuff off of a roll, but the 10ft tubes (though cut into shorter lengths).

I made lighted window frames with dumb RGB flex strips and they are a little too bright.
I suppose I could dim them in software, but I think a half-tube of PEX covering would both Dim and Diffuse them to look better.

I have a small table saw and could try it. Just wondering if anyone has done it already.

I haven't tried with the PEX but have with regular PVC.  Very difficult as the pipe wants to jump around and vibrate just enough that you end up with very rough edges.

I haven't tried it, but I did see on a forum where a user wanted to cut a grrove in the pipe to put it over some re-bar.  The best suggestion I saw was to use a router and first cut a 4x4 block with a hole through it the same diameter as the pipe, and one on the bottom for the router bit.  Then secure the 4x4 to the router fence.  As an additional tool to stop the vibration they inserted a wooden dowel in the pipe before threading it through the 4x4.  Sounds like a lot of work just to cut a groove, but if you are determined enough you could give ita  try.

[jnealand]

The way I have seen nice grooves cut is build a long trough out of a couple of boards where the pipe just fits inside.  Lock the pipe so it cannot spin and run a router along the top of the trough.   You would need some kind of an edge of centering mechanism to keep the router bit centered on the pipe.  Unfortunately I did not save the link to that example.  hopefully you can get the picture in your mind.

[CW]

Here is a link for pex vs thin wall pvc.  The top pipe is 3/4" thin pvc and the lower and brighter is 3/4" pex.  I used Ray Wu's TH-2010 controller and smart string strip.

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I used pex this year and what I like about it is translucent due to it does not have pigment added like pvc does.  Polyethylene is translucent in it's natural state. It does a nice job defusing the lights so it looked like neon.  It did have hot spots where the lights are but frankly that was not a bad in my opinion.

I used 1\2" with dumb string strips around my windows and I used 3\4" with smart string strips in a half mega tree.  I have video that I need to finish and I will post so you can see the pex in action.

Craig