PVC Pipe vs. Arizona Sun

Any light colored EXTERIOR latex paint is fine (in my experience), unless it is initial installation - you can get UV resistant PVC - but it sounds like an existing system.

I'd recommend something that matches the house - or the privacy fence, or your CoolDeck.

Buy UV resistant pipe, they can add carbon to the pipe and make it perform in direct sunlight.

That's about what I expected, just wanted to check in with the brain trust to make sure.

Regular acrylic paints are compatible to PVC, they do fine. Apply two or three hands and be sure your pipes will last longer (and look better too if exposed in a visible area). I have painted mine, and all houses around to have painted their exposed PVCs to match the wall colours with just the same paint (by the way, all houses around here are made of bricks - I have visited Arizona a number of times and know everybody there build using wood and dry wall stuff...). It works. And, if I were you, I'd paint even the sun-resistant PVC if I had a chance to install it.

I replaced the PVC plumbing on my pool, after 30 years of direct exposure to the AZ sun. I bought a new filter. The PVC pipe was fine.

Painting it is also very good advice.

I am thinking Coopertone, SPF 60 or so....

Wrap it with gold foil .. it works for NASA... or Aluminium cooking foil...it works for my Sunday Chicken
Del

That anything works for NASA is a minor miracle, I think there is an alternate set of 'universal laws' for the folks at NASA which might have catastrophic effects when applied in the 'normal' world...

Though some aluminum roasted chicken does sound good... The sidewalk should be up to cooking temp pretty soon so I better start chopping some onion and garlic, maybe a little thyme and citrus too... MMMmmmmmm... chicken good...

Exactly. Or use steel or aluminum tape roll. We use it all the time in the sheetmetal business (outdoors too).

PVC Conduit is listed as "sunlight (UV) resistant" and is much more resilient to UV than it used to be, but it will breakdown before life of the electrical system (60 years), and it is not listed for use in direct sunlight. If you paint it, it should be noted that it loses its UL Listing unless you use a UL Approved paint.

Those are the reasons an engineer should never approve the use of PVC.

All official things put aside PVC is used frequently on outdoor applications, but you should consider its duty cycle. Is it exposed to heavy traffic, abuse, etc.? I am not sure painting would help but it could make it look nicer. I suggest you use schedule 80 and not 40. Or if you really want a better, longer lasting system use schedule 80 plumbing pipe since it was designed around entering and leaving the soil and was approved for use in direct sunlight. Its just not UL Approved for electrical use.

Grey Haired Old Goat wrote:

"If you paint it, it should be noted that it looses its UL Listing unless you use a UL Approved paint."

Interesting!

And, embarrassing that I should have overlooked the loss of dielectric rating likely from painting anything with a carbon rich paint as I suggested.

Admitedly, the application appears to be for handling water, not electric circuits, but we don't know that, do we?

There are consequences from assuming anything.

Thanks!

L.J.

The application in question is in fact for water handling not electric circuits, the rotted pipes in question were part of a pool pump/filtration system. I suspect when they did the initial install they bought the cheapest pipe they could find and didn't pay much attention to the specs. They certainly didn't paint them.

All the sail covers in San Diego Bay are blue. There must be a reason.

Carbon black just doesn't do a thing for me.

As I stated earlier, my totally exposed, unprotected, 30 year old AZ. pipe was still in fine shape when I replaced it.

Black tubing is resistant to sunlight and UV

http://www.usplastic.com/catalog/product.asp?catalog%5Fname=USPlastic&category%5Fname=120&product%5Fid=7832

I'm not certain (it's not my pool, I'm researching for a co-worker) but I believe the pipe is roughly 2" i.d. so the tubing idea doesn't look like it will work out (I didn't see anything larger then 1.5" o.d. and I didn't check pressure ratings.

Great idea though, I'll keep it in mind for other projects.

In another life I had a pool in Tucson with several small lengths of 3/4" PVC water pipe exposed to the sun. In 13 years, I never noticed any deterioration of the material.

OTOH, the HDPE pipe we used was totally black. The suppliers said that was to protect against UV degradation during storage; because it was never installed above ground.

the weak Canadian sunlight might have needed several more decades to do the damage your Arizona sun can do in only a few years.

err more likely what the AZ sun can do in a few months

aluminium tubing used in agricultural irrigation becomes brittle in about eight months in the AZ sun and is then exchanged for fresh tubing.

GA and thanks for the suggestion.

My initial searches on the subject said 'PVC is not severly impacted by UV...' clearly the author of this statement has never stood in the sun in Arizona or found the pipes for their pool crumbling away into nothingness as a result of constant baking.

Question? Did the PVC crumble into nothingness?

I heard that the glue used with PVC cannot withstand hot water applications?

Anyone ever run across joint leaks from PVC glue?

landedusaSo.Cal.OC

If one follows the directions when gluing PVC connections one may experience performance the manufacturer claims the product is capable of concerning leakage.

How hot is the hot water?

I haven't seen it myself, but as it was described to me the PVC 'crumbled' at the slightest pressure... I'm guessing the 'crumbling' occured on the side exposed to the sun.

I cover mine with half round concrete pipe sections

Anywhere else I would say great idea... it's still a pretty good idea for here, provided you remember to check for black widows and scorpions before lifting the pipes.

Fortunately most of the snakes and gila monsters stay out of the city, anyone wanting to do this in a rural area of AZ could be asking for trouble...

How cute...

definitely cute is the word...

I've lived in rural AZ both low desert and mountains. The dangerous critters you mentioned find their hiding places too. We never go outside without shoes on, not ever. So half round pipe is fine and they like it too, in those out of the way places where no one bothers them.

When I need to look things over I can pound the ground with a tamper and they scoot.

Ya know if the ground temperature is above 90°F snakes and Gila's are under ground to keep their blood from boiling.

That's very true, but there has been such a huge population boom here that I feel compelled to put out the caveat since folks from 'back east' (or up north or...) may not be aware that they have moved into a hostile environment, and the last thing I want to hear is "you told me this would be a good idea and then my daughter got bit by a ____"

While I'm on my soapbox... If you plan to come visit our beautiful desert here are some things to watch out for...

Always watch where you are running/jogging...

Sometimes the ground 'disappears' suddenly

Big birds =

big car wash bills

And never throw your pocket change in the car seat!

I tried everything but sun block on PVC. What we call dirt here is red clay and PVC pipe burried in it becomes super brittle in 5 years, 2 years for the thin wall stuff. Any runs going up hill must include at least 2 sliding expansion joints. Above the ground over grown with grass and weeds PVC pipe serving as a by pass line became so brittle it would crack if you look at it wrong in 6 months.

We solved the problem with 1 inch steel pipe.

I like the steel pipe idea, except for two things...

1) Lots of salts in local bedrock/water supply (and the pipe would be handling heavily chlorinated pool water to boot) so corrosion would be high or we'd be looking at spending extra money for stainless (if not for issue two I'd probably consider the investment in stainless to be a good one)

2) My wife had a portrait of Abe Lincoln on her butt for about 4 years after getting into the car with shorts on (should have checked the seat for pennies), any metal left in the summer sun for more then about 20 minutes will be capable of causing severe burns... The PVC will also eventually get hot enough to burn but it releases it's heat energy more slowly so you have a chance to let go before the damage is done.

These blog testimonials and recommendations are interesting, and I think so are some related materials science and physics. In this regard, I noticed the reference http://books.google.com/books?id=gWg-rchM700C&pg=PA583&lpg=PA583&dq=UV+breaks+plastic+molecular+bonds&source=bl&ots=xGG8rIVyrh&sig=p6mMeCpsXiTQlZgc6aO62ntJSFg&hl=en&ei=IpERSsj9CtSJtgeU5uj0Bw&sa=X&oi=book_result&ct=result&resnum=4 e.g. addresses these issues with the explanation, "All types of solar radiation have some detrimental effects on plastics. The energy in ultraviolet radiation is sufficiently strong enough to break molecular bonds. This activity in the polymer brings about thermal oxidative degradation that results in embrittlement, discoloration, and an overall reduction in physical and electrical properties."

I believe even light colored plastic pipes will often also get very hot in relentless desert sun light (in some cases due to absorption, much hotter than ambient temperature), and it should also be remembered that beyond degradation effects as mentioned in paragraph 1 that the long-term strengths, moduli and stiffnesses unquestionably go WAY DOWN with increasing temperature plastics (even if one were to ass/u/me absolutely no "degradation"). Another thing to remember is that exposed plastic pipe systems move or try to move much greater/further as mentioned also by another, in response to inevitable exposed piping temperature fluctuations, e.g. every day and night, due to MUCH greater coefficients of thermal expansion/contraction (the thermal expansion coefficient of pvc is e.g. nearly five times that of steel pipe than e.g. metal pipes). This could conceivably cause problems e.g. due to fatigue or stressing at supports or penetrations of common concrete or steel structures in some systems that do not move as much.

While it is true there are plastic additives e.g. absorbers and/or stabilizers that inhibit this effect by various means, as far, as I know they are not claimed 100% effective nor permanent. Likewise, barrier paints as mentioned already by others also have practical limitations and maintenance issues. [I don't doubt this as while I have seen extruded plastic pipes that are not necessarily real smooth on the inside, they do however appear to be near universally VERY smooth on the outside of the pipes. This doesn't supply a very good "anchor" pattern for paints to stick to, nor is the adhesion, durability, and appearance of paints perhaps helped much by the inherent exaggerated thermal movements of plastics in all directions as explained in paragraph 2.]

You may also be interested in an abstract I noticed some time ago that is available at http://www.gcrio.org/ozone/chapter7.pdf of a paper reportedly written a few years ago, involving exposure of pvc pipes in Saudi Arabia as well as Miami, FL (collaboration of some researchers with Saudi Arabia's King Faud University as well as some in the USA (@ Miami, FL). I remember reading some results of both research locations and pipe investigations reported therein that included, "The data that show PVC pipe lost 50 percent of its elongation at break within 12 to 16 months at Dahran…" and more than 24 months in Florida during outdoor exposure. As I don't think that amount of duration of exposure is all that unusual, I believe it is conceivable this could also have some implications as well in conventional "fracture toughness" and "critical crack length" (likelihood to break as a result of flaws and imperfections etc.), far below the normal room temperature properties and frailties of pvc pipe. Vinyl chloride monomer also has apparently been shown not long ago by this same research institution as reported at http://www.springerlink.com/content/w014rp211421l186/ to migrate from some pvc pipes etc. into some water [at least with some water chemistries and/or temperatures at or beyond 45 degrees C. (~113 degrees F.)]

GA, thanks for the references.

Krylon spray paints have a new product formulated specifically for painting plastics, it's named 'fusion', supposedly bonds at a molecular lever or so they say.

Covering PVC with foam insulation and wrapping with six mil plastic film (white) may extend life of the materials.

"supposedly bonds at a molecular lever or so they say."

I'd have to take issue with any molecular "bonding". Just ain't so.

It is more solvent "bonding" than molecular.

I do believe that the K company makes an excellent product, as do others.

I'd use a blue color for Uv absorption, too.

BTW, crumbling could be a sign of solvent degradation.

It's the language of the deal

Please give a reasonable description why one would want to absorb UV

I'll get back to you.

bwire, I believe the argument that "absorbers" help the plastics is that they supposedly convert at least some of the unquestionably killer effects of UV to "less harmful" forms of radiation (notice they don't say "innocuous" effects). While I would defer to more knowledgeable materials folks, I suspect they most often probably mean they convert this form of energy to thermal (heat, and inevitable thermal fluctuations etc., that do have many deleterious property effects on plastics and probably also paints etc. as I explained in a previous response to this thread).

Thank you, I was curious about the use of the blue color rather than black and what properties are expected of UV, is it absorbed when coming in contact with the plethora of substances on the earths surface or does bounce around until meeting a blue colored surface?

The foam insultaion and tape cost more than the PVC pipe.

Yes but only one time. In fifteen years it will have paid for itself twice

insulating foam and tape will degrade vastly faster than PVC pipe. It is really not the kind of material you want exposed to sunlight and physical forces encountered outdoors. So if you gain an extra 10% or 15% life on the PVC pipe, you expend much more than you would by replacing the pipe when necessary. Would be much cheaper just to get a heavier grade of pvc pipe, and if possible with carbon added for extra UV resistance.

Yes, and the foam and tape will end up in the pool sometime when the wind is blowing 25 MPH and there's a 5000 foot tall, by five miles wide, wall of dust coming in two minutes.

I did leave out the windscreen and shade eh

well this might be a little extreme but if its was my pipes I'd in case a larger PVC pipe over the original and flush inside this pipe nitrogen liquid coolant this will prevent pipe cracking from high temperatures. We use this in Computers to cool them down so the hard drive will not over heat and fry the main frame but in your case this odd ball trick might save you in the long run from replacing pipes all the time. The coolant you can get at any auto store such as advanced Auto, NAPA Auto, Auto Zone, etc. Make sure to seal the end of the outer pipe around your main I'd use a little cement to fill in around both ends of the like this _________________________

======================

_________________________ the inner section is your pipe you require but the other will act like AC unit to your main pipe and to the exterior PVC that should cut down on the heat cracking the PVC if you would like more help on this topic my email is mercinary2003@yahoo.com just right PVC topic and I'll know who you are. Hope some Engineering advice could help!!

Alright, I have to say this is definitely an extreme response to a pool repair issue, but I like it...

of course if I'm going that far I'm gonna want to add a compressor/condensor set-up to it as well so I can have a shockingly cold pool... then I can start work on developing 'pool-berg' technology so kiddies with RC boats can play titanic in the pool... I'm certain there is a market for this! The super cooled pool water may also decrease pool related deaths as drowning victims benefit from the metabolic slowing brought on by cold water immersion... this does indeed get better and better...

While I don't think it helps me with this instance, I do appreciate the idea and the thought train that followed it. Thanks for the input.