Brent wrote:
I'm curious why they paint all the white 2-inch PVC pool pump area pipes
flat black?

On Friday, I put a new pool pump motor in but forgot to open all the Jandy
valves so the pipes overheated, expanded, and blew up in places (a 1.5 HP
motor is strong!).

Anyway, my 2 inch outside diameter PVC pipe from Home Depot earlier today
now stands off as bright white while the rest of the pipes re painted flat
black.

No big deal but I was wondering WHY they paint the PVC pool pipes black and
if it's a good enough reason for me to follow suit on my 2-foot section of
repair pipes.

The three reasons I can think of don't seem to hold water:
- heat retention? (c'mon ... how much heat will black retain over white on
a few pipes that are in the open sun?)
- sunlight damage? (maybe ... but then why don't they just sell pool pipes
that have paint on them already)
- asthetics? (c'mon ... can black matter versus white)

Any other reason for the flat black pool pipe paint?

The paint is to protect the PVC from the UV of the sun. White paint,
(or green or red or blue) would work just as well.

On 4/19/2010 8:51 AM, Steve Barker wrote:
Brent wrote:
I'm curious why they paint all the white 2-inch PVC pool pump area pipes
flat black?
On Friday, I put a new pool pump motor in but forgot to open all the
Jandy
valves so the pipes overheated, expanded, and blew up in places (a 1.5 HP
motor is strong!).

Anyway, my 2 inch outside diameter PVC pipe from Home Depot earlier today
now stands off as bright white while the rest of the pipes re painted
flat
black.

No big deal but I was wondering WHY they paint the PVC pool pipes
black and
if it's a good enough reason for me to follow suit on my 2-foot
section of
repair pipes.

The three reasons I can think of don't seem to hold water:
- heat retention? (c'mon ... how much heat will black retain over
white on
a few pipes that are in the open sun?)
- sunlight damage? (maybe ... but then why don't they just sell pool
pipes
that have paint on them already) - asthetics? (c'mon ... can black
matter versus white)

Any other reason for the flat black pool pipe paint?

The paint is to protect the PVC from the UV of the sun. White paint, (or
green or red or blue) would work just as well.

Black pigments are the most effective UV absorbers.

On Mon, 19 Apr 2010 09:14:44 -0400, George wrote:

The paint is to protect the PVC from the UV of the sun. White paint, (or
green or red or blue) would work just as well.

Black pigments are the most effective UV absorbers.

I wonder why they don't just sell black PVC 2" OD pipe then???

Even at Leslies' Pool Supply, they're white.

Everyone seems to just paint them.

It's cheap and easy; but I was just wondering why we don't just start out
with UV-resistant PVC pipe???

Brent wrote:
On Mon, 19 Apr 2010 09:14:44 -0400, George wrote:

The paint is to protect the PVC from the UV of the sun. White
paint, (or green or red or blue) would work just as well.

Black pigments are the most effective UV absorbers.

I wonder why they don't just sell black PVC 2" OD pipe then???

Even at Leslies' Pool Supply, they're white.

Maybe they don't want to confuse PVC with ABS?

On Mon, 19 Apr 2010 13:34:01 -0700, Bob F wrote:

Even at Leslies' Pool Supply, they're white.
Maybe they don't want to confuse PVC with ABS?

I think I found a clue why I need to use (white) PVC and not (black) ABS
pipe fittings in the high-pressure side of my pool plumbing!

http://www.swimming-pool-repair.net/plumbing.html
"ABS is not pressure rated for applications such as a pool plumbing sytstem
and an ABS pool system will be likely to develop leak problems
prematurely."

Also ...
"ABS pipe can be identified by its black color and the yellow glue used to
fuse the fittings to the pipe. PVC is generally white and should have a
wall thicknes of 40mm commonly refered to as schedule 40."

Since I used the "blue" glue, I wonder if it will make a difference with my
single accidental ABS fitting???

On Mon, 19 Apr 2010 16:59:17 -0400, wrote:

I wondered about this myself. Is the OP sure the original pipes
weren't ABS?

We have LOTS of sun here. All day sun.

I'm not sure if it's ABS or PVC for all the pipes, but the pipes I bought
at Home Deport say they are PVC.

What made me wonder about the black versus white was I needed a fitting and
I grabbed one that was black through and through. I mixed it in with the
white fittings and then painted the white ones.

I wonder (based on the ABS question) if that one black fitting was ABS
while the rest (the white ones) are PVC?

That makes me wonder: What's the difference from a practical standpoint for
outdoor 12-hours-a-day-in-the-sun 2-inch OD pool water pipes between black
ABS and white-painted-black PVC pipe?

Note: Leslies pool supply sold only the white PVC so maybe I should have
asked the teenager behind the counter but I didn't think of it when I was
there.

On Tue, 20 Apr 2010 00:00:31 +0000 (UTC), Brent wrote:

What's the difference from a practical standpoint for
outdoor 12-hours-a-day-in-the-sun 2-inch OD pool water pipes
between black ABS and white-painted-black PVC pipe?

"The Effects of Ultraviolet Radiation on PVC Pipe"
http://www.uni-bell.org/pubs/uni-tr-5.pdf

Summarized by the PVC Pipe Association he
http://www.uni-bell.org/faq.html

Further summarized by yours truly below:
Q: What effect does ultraviolet exposure have on PVC pipe?
A: Not much but enough to warrant a thin coat of opaque paint!

Modulus of Elasticity = unchanged after two years of sun
Tensile Strength = unchanged after two years of sun
Impact Strength = reduced drastically (by 75%) after two years of sun
Structural Integrity = unchanged after two years of sun
Pressure Capacity unchanged after two years of sun

The loss of impact strength stopped deteriorating as soon as the pipes were
protected by the sun so it's directly related to the UV radiation.

Luckily, the presence of an opaque surface between the sun and the pipe
prevents UV degradation, since UV radiation will not penetrate thin shields
such as paint coatings or wrappings or burial.

Why black? What's more opaque than black? Electrical PVC outdoor pipe is
gray. Go figure.

PS: I heard some paint won't stick to PVC so maybe you need special PVC
paint?

Painting black reduces the absorption of UVA, B, and C so that the pipe
lasts a little longer.

On Mon, 19 Apr 2010 21:18:37 -0400, wrote:

If you cut the end and it is black in the middle, it is ABS.
That is what the solar contractors use.
Pool contractors use PVC for the regular pool plumbing.

Given that, ALL the pipes I cut were white on the inside (with purple glue
at the seams).

A single 4-inch-long sleev-like fitting I grabbed out of the miriad of
various elbow-like fittings I bought at the hardware store was black all
the way through as I had to cut it to fit.

So, given that black is ABS and white is PVC, my pool plumbing is currently
99% (white) PVC with that single fitting of (black) ABS that I used without
knowing the difference.

Now that I realize I've mixed ABS with PVC ... I wonder ... does it matter
that I have ABS accidentally mixed in with mostly PVC (painted black)?

"Brent" wrote in message
...
On Mon, 19 Apr 2010 09:14:44 -0400, George wrote:

The paint is to protect the PVC from the UV of the sun. White paint, (or
green or red or blue) would work just as well.

Black pigments are the most effective UV absorbers.

I wonder why they don't just sell black PVC 2" OD pipe then???

Even at Leslies' Pool Supply, they're white.

Everyone seems to just paint them.

It's cheap and easy; but I was just wondering why we don't just start out
with UV-resistant PVC pipe???

If it makes any difference mine are all still white. I don't remember seeing
any that were painted any color. That's weird that it blew up. I had my
waste valve closed one time and tried to back wash. I didn't have it on long
so it didn't do anything. I'm glad you said something because I never would
of imagined that could happen. I'll bet your motor seal goes out soon if it
isn't gone already.

I'm always afraid I'm going to do something stupid like that.