A month ago I found a leak in the sprinkler.
No problem, you dig, splice and repair.
Apply the pressure and another elbow nearby blows open.
At this point I get a little suspicious and stress mildly all other joints
in the dig and got 2 more to fail nice an clean, you can tell that there was
no good bonding.

Also note that the cement used was a deep blue, not the usual transparent
stuff with the tell tale of the purple primer.

The blue cement appears to be like a thick paint, the failed joints can be
easily cleaned with steel wool and the cement residue does not seem to be
fused with the rest of the fitting as I would expect.

Same story, I stressed the stub and I got the entire valve assembly out. I
was able to break out the pipe stubs from the valve. All pretty poor joint,
little sign of cement.

Other notes. The water utility started adding free chlorine for the annual
flushing, this is a temporary thing. Could this be a factor?

I never had any problem with the transparent type of cement applied over the
purple primer.

Is this blue cement different? Incompatible with PVC?

I do not believe movement or stresses are a factor here.

Anyone can shed some insight?

Thanks MG

MG wrote:
A month ago I found a leak in the sprinkler.
No problem, you dig, splice and repair.
Apply the pressure and another elbow nearby blows open.
At this point I get a little suspicious and stress mildly all other joints
in the dig and got 2 more to fail nice an clean, you can tell that there was
no good bonding.

Also note that the cement used was a deep blue, not the usual transparent
stuff with the tell tale of the purple primer.

The blue cement appears to be like a thick paint, the failed joints can be
easily cleaned with steel wool and the cement residue does not seem to be
fused with the rest of the fitting as I would expect.

Same story, I stressed the stub and I got the entire valve assembly out. I
was able to break out the pipe stubs from the valve. All pretty poor joint,
little sign of cement.

Other notes. The water utility started adding free chlorine for the annual
flushing, this is a temporary thing. Could this be a factor?

I never had any problem with the transparent type of cement applied over the
purple primer.

Is this blue cement different? Incompatible with PVC?

I do not believe movement or stresses are a factor here.

Anyone can shed some insight?

Thanks MG



You pretty much described the problem. Whatever the blue cement was it
is clearly not compatible with the plastic pipe because it never
dissolved the plastic (what a solvent cement does) to form a bond.

"MG" wrote in message
ink.net...
A month ago I found a leak in the sprinkler.
No problem, you dig, splice and repair.
Apply the pressure and another elbow nearby blows open.
At this point I get a little suspicious and stress mildly all other joints
in the dig and got 2 more to fail nice an clean, you can tell that there
was
no good bonding.

Also note that the cement used was a deep blue, not the usual transparent
stuff with the tell tale of the purple primer.

The blue cement appears to be like a thick paint, the failed joints can be
easily cleaned with steel wool and the cement residue does not seem to be
fused with the rest of the fitting as I would expect.

Same story, I stressed the stub and I got the entire valve assembly out. I
was able to break out the pipe stubs from the valve. All pretty poor
joint,
little sign of cement.

Other notes. The water utility started adding free chlorine for the
annual
flushing, this is a temporary thing. Could this be a factor?

I never had any problem with the transparent type of cement applied over
the
purple primer.

Is this blue cement different? Incompatible with PVC?

I do not believe movement or stresses are a factor here.

Anyone can shed some insight?

Thanks MG

I believe the blue glue is for wet situations. It sounds like whoever did
the install did not use primer or let it sit to long primed without gluing.
A common practice is to prime a bunch of fittings and grab as you need
them.The primer softens the pipe so the glue holds better if you let it sit
to long the primer dose no good. Some people think you don't even have to
primer the pipe, see how long that holds.

The BEST joints (strongest, longestest lasting, problem free) are made
with primer followed by light bodied clear cement.

In 35 years of experience I've never had a joint problem using primer
followed by clear cement. Prime just prior to cement.

The only joint failures I've had was when I switched to blue (Red Hot)
cement. I thought it would be better since all the "pros" use it.
It's just faster not better. I was wrong, I'll never use or suggest
the use of the blue stuff.

cheers
Bob

"MG" wrote in message
ink.net...
A month ago I found a leak in the sprinkler.
No problem, you dig, splice and repair.
Apply the pressure and another elbow nearby blows open.
At this point I get a little suspicious and stress mildly all other joints
in the dig and got 2 more to fail nice an clean, you can tell that there
was no good bonding.

Also note that the cement used was a deep blue, not the usual transparent
stuff with the tell tale of the purple primer.

The blue cement appears to be like a thick paint, the failed joints can be
easily cleaned with steel wool and the cement residue does not seem to be
fused with the rest of the fitting as I would expect.

Same story, I stressed the stub and I got the entire valve assembly out. I
was able to break out the pipe stubs from the valve. All pretty poor
joint, little sign of cement.

Other notes. The water utility started adding free chlorine for the
annual flushing, this is a temporary thing. Could this be a factor?

I never had any problem with the transparent type of cement applied over
the purple primer.

Is this blue cement different? Incompatible with PVC?

I do not believe movement or stresses are a factor here.

Anyone can shed some insight?

Thanks MG



Thanks to all. I am no pro, but my limited experience is that the blue
stuff is no good.
Also learned today the function of the primer.
MG

Sounds like they did not use primer. I see it all the time.

Stretch

"MG" wrote in message
ink.net...
A month ago I found a leak in the sprinkler.
No problem, you dig, splice and repair.
Apply the pressure and another elbow nearby blows open.
At this point I get a little suspicious and stress mildly all other joints
in the dig and got 2 more to fail nice an clean, you can tell that there
was
no good bonding.

Also note that the cement used was a deep blue, not the usual transparent
stuff with the tell tale of the purple primer.

The blue cement appears to be like a thick paint, the failed joints can be
easily cleaned with steel wool and the cement residue does not seem to be
fused with the rest of the fitting as I would expect.

Same story, I stressed the stub and I got the entire valve assembly out. I
was able to break out the pipe stubs from the valve. All pretty poor
joint,
little sign of cement.

Other notes. The water utility started adding free chlorine for the
annual
flushing, this is a temporary thing. Could this be a factor?

I never had any problem with the transparent type of cement applied over
the
purple primer.

Is this blue cement different? Incompatible with PVC?

I do not believe movement or stresses are a factor here.

Anyone can shed some insight?

Thanks MG

The primer that I always use is blue, possibly the pro that installed yours
thought it was glue? My house had a system installed before I bought it. One
of the joints going to the backflow failed when the guy that tested it for
me dug up the box around the backflow valve and put pressure on the pipe
when he put the box back in the ground. When I dug it up it had no glue,
just the blue primer.

CR