PVC Primer + Cement or All-in-One ?

RickDelta · April 4

Hi!

Anyone have experience with the "All-in-One" PVC cements?
Don't know if its better or not.

Thanks!

(pressure application)

ChrisJ · April 4

Can you share a link for such a product?

I don't know how it's possible.

RickDelta · April 4

https://cleanfit.com/blue-monster-pvc-cement.shtml

GGross · April 4

There are many brands of PVC cement that will state on the can that you can use them without primer, this is generally not a great idea though, and in many jurisdictions not allowed by code anyway. the blue monster product has the same stipulation "Use without primer where acceptable by local code"

I had some customers ask me about this a few years ago and was surprised to find that most of the PVC cement on my shelf also said you did not need primer. My personal opinion, if it matters enough to do right, then you might as well use primer and follow the most generally accepted professional installation methods

kcopp · April 4

I have used the Gorilla stuff for years.
The biggest advantage is the odor and toxicity...
MUCH better.
Disadvantage is the temp rating. You cant use it below 40F
I hate typical primer and cements.
Do

KC_Jones · April 4

The pipe manufacturers will say no to all in ones, it's not possible to be a proper joint with an all in one. The "primer" has a function, the "glue" has a function. The primer is actually the most important.

The glue is not glue, it's solvent with PVC dissolved into it as a filler. The "Primer" is basically pure solvent. So, the Primer actually melts the PVC more and is the primary part of the joint. The glue (with filler) is simply to close up any gaps since the sockets are tapered, the bottom is an interference fit, the top has clearance, that's where the glue comes in. The Glue is definitely not the primary bond in the joint.

The PVC manufacturer we deal with (Spears) will not back up any product failures unless primer and glue are used. I would assume they all have similar nomenclature in their warranty information.

I'm with @ChrisJ I don't see how an all in one can fulfill both requirements.

JUGHNE · April 4

By "primer", I assume we are talking about "cleaner" which will clean off almost anything, (including your fingers) and soften up the pipe and socket to where the Material will flow to weld.

For me no Purple involved, IMO it does not prime, clean or soften anything and just makes a mess.
However I have been told if you add some to your pvc solvent it will give you a nice color ring on the socket so you know you applied the "glue".

I have repaired or pulled apart many joints that never had the primer/cleaner used on them.

I also have had a helper clean/prime fittings and then "dry fit" them together to never come apart.

Intplm. · April 4

What the primer, also referred to as cleaner, does is brake down the shine or sheen on the pipe exposing the softer inner portion. You can get the same result by using sand cloth to remove the sheen.
Then the glue is used to make the solvent weld. It's a pretty clever process with great results when done right.
I haven't used the one step stuff.
As like many of us, Im a bit Leary of using something that is new and a one step process.

ChrisJ · April 4

What @KC_Jones Said is my understanding as well.

The sheen on the plastic is still the same exact plastic that's under the surface and the solvents in both the primer and cement melt it. I believe the primary solvent used in this is MEK.

Acetone maybe another.

ChrisJ · April 4

The way these joints work are the sockets are tapered. You use solvents to literally melt the plastic and then force the pipe into the tapered softened joint. The solvents leave and the pipe and fitting returns to original state except they're melted together.

The PVC cement has plastic dissolved in it to help fill in areas.

That's my understanding.

I have no idea if the 1 step stuff works I guess it has extra solvents in it I don't know. Honestly above my pay grade. I'm about to do a lot of PVC pipe in my own house using Hercules cement and clear primer.

kcopp · April 5

Typically w/ the one step they recommend giving it a quick hit w/ some sandpaper. Not a bad idea anyways to get rid of extra burrs and any junk that may be on the pipe.

Mad Dog_2 · April 5

The only time I've used it is on Orange CPVC for residential fire sprinklers I've installed. Very thick..Mad Dog

MikeL_2 · April 5

You can find the required methods for solvent welding / bonding on pipe and cement manufacturers websites.
A common error I see is failure to properly ream the inside & outside of pipe. And that includes plastic, copper, steel, brass, etc...

ChrisJ · April 5

kcopp said:
Typically w/ the one step they recommend giving it a quick hit w/ some sandpaper. Not a bad idea anyways to get rid of extra burrs and any junk that may be on the pipe.

MikeL_2 said:
You can find the required methods for solvent welding / bonding on pipe and cement manufacturers websites.
A common error I see is failure to properly ream the inside & outside of pipe. And that includes plastic, copper, steel, brass, etc...

The burr on the outside edge of the pipe is by far the biggest issue I've seen. It tends to cut the softened plastic in the fitting and push it up into the fitting rather than just mush into it. If it cuts it and pushes the material away it has less to melt together. I always hit the outer edge with sandpaper to get rid of that. A deburring tool can work as well, but I find that easier to use on the ID of the pipe.

Also agreed, the pipe and fitting should really be extremely clean. No dirt, dust etc.

Unfortunately it's very difficult to keep this stuff really clean when laying in someone's nasty crawlspace. Especially when the pipe seems to be staticky and everything wants to stick to it.

dko · April 5

You basically mix primer and cement within seconds anyway.
All chemicals in primer is in cement, just varying percentages (but not vice-versa).
Primers have a significant more acetone and cyclohexanone.

Blue Monster's 1-step is very close to regular cement chemical makeup.
If you were to use 1-step, I'd recommend the Oatey Fusion. That chemical makeup makes more sense.

Mustangman · April 5

When PVC with solvent weld joints first came about, there were 3 steps. Cleaner was simply that.. it cleans the pipe.Primer is a sofenting agent so to speak. If you put primer on a piece of pipe, take your finger nail and you can actually scratch into the plastic. Last is cement. Put the fitting and pipe together and 1/4 turn and hold for 30 seconds. If you don't hold it, it can and will come apart on its own.
Very simple here where I live.. the inspectors don't approve of the all in one glue / cement. I'm old enough to remember when PVC first became popular. The purple primer is simply to cover the pipe and fitting companies asses. Many guys would skip cleaner and primer and just glue it. Well needless to say there were leaka, failures and lawsuits because primer was not used. Primer is almost as important as the cement. You can do a nice looking job if you are very careful how much primer you put on the dauber. If you use it almost dry, you can avoid those ugly spider runs and you have this thin purple ring around the joint.
They now have unpurple primer. It is clear. If you shine a UV light on the joint, you can see the primer.. it turns purple. Codes allows that primer here. I have a UV flashlight for the inspectors to use. I've been
known to just give the flashlights to the inspectors. Hey you do what it takes.
Steve

RickDelta · April 6

Its important to chamfer the outer pipe edges, if not, that razor sharp edge will remove all the cement (dry spot) it comes in contact with. The chamfer allows the cement to get in between the inserting pipe and the fitting.

I blue tape down to the insertion depth of the fitting before I purple prime, this gives me an indication of when the pipe is fully seated.

KC_Jones · April 6

@RickDelta

Based on your pics it appears you are letting the primer dry before assembly. That would be 100% wrong. The amount of time it is left open is enough to assemble 1 joint. No way you can prime and assemble 4 joints properly. You appear to be taking the time to use the primer, and yet doing it wrong basically negating the use of it.

It is pretty, but wrong.

Again, the primer and glue are to be wet when assembling.

Intplm. · April 7

KC_Jones said:
@RickDelta

Based on your pics it appears you are letting the primer dry before assembly. That would be 100% wrong. The amount of time it is left open is enough to assemble 1 joint. No way you can prime and assemble 4 joints properly. You appear to be taking the time to use the primer, and yet doing it wrong basically negating the use of it.

It is pretty, but wrong.

Again, the primer and glue are to be wet when assembling.

Agreed.. to some extent. A good joint is one that doesn't leak and will not leak.

Try this. Use sand cloth instead of primer on PVC or CPVC. Prep the joint with the sand cloth as you would to clean copper for soldering. Removing the shine from the pipe and fitting. Do this in place of the primer. Now use the glue. Your joint will be true and sound.
In the early nineteen eighties new and out of trade school the company's I worked for did this. It blew my mind and it worked.
The above what @RickDelta does isn't necessarily wrong in letting the primer dry.
I use primer always now. When I left the earlier employment, primer was and is the go to from then on. Its a lot easier then using sand cloth to expose and soften the joint preparation.
Yes I know what the directions say from some manufacturers and yes I have heard all of the arguments but when you are on call late at night and not in your own vehicle. Some one didn't put the primer back in the truck or it spilled. Try it if you like, or don't, It's what was done by some when PVC was first coming into use.
My experience tells me that there can be six ways to do something and they all can be right.

ChrisJ · April 7

@Intplm.

The objective in solvent welding is softening the plastic so they can melt together. Primer softens the material. Sand paper removes material.

I don't understand how these are interchangeable?

You're absolutely correct there can be many ways to get something done. There's also times when following the book fails but breaking the rules works.

kcopp · April 7

This is what I do w/ the 1 part Gorilla glue. 80 grit sandpaper.

Intplm. · April 7

@ChrisJ And neither did or do I. It blew me away. I had a serious case of the ****'s.
But Im thinking..and this is a guess that many in the late seventies and early eighties used sand cloth, and it was a big PIA to do it that way so primer was brought about as a solvent for the solvent weld??

Look at electrical PVC. No shine, no sheen. No primer needed. I don't use flo-guard gold much but that doesn't have the shiny sheen either. I have seen it installed without primer too.

ChrisJ · April 7

Electrical conduit doesn't have to hold pressure in fact I don't think it even needs to be liquid tight.

Intplm. · April 7

ChrisJ said:
Electrical conduit doesn't have to hold pressure in fact I don't think it even needs to be liquid tight.

Very good point. Electrical PVC doesn't have that smooth shine/sheen on it to allow solids to flow smoothly inside.
DWV pvc has the shine ..smoothness for proper drainage flow.
DWV pvc is made to keep fluids, in. Electrical pvc is made to keep water out protecting wires.
And it is not pressure rated.

neilc · April 7

I have never see electrical pvc that didn't have water in it to the ground flood line

RickDelta · April 7

KC_Jones said:
@RickDelta

Based on your pics it appears you are letting the primer dry before assembly. That would be 100% wrong. The amount of time it is left open is enough to assemble 1 joint. No way you can prime and assemble 4 joints properly. You appear to be taking the time to use the primer, and yet doing it wrong basically negating the use of it.

It is pretty, but wrong.

Again, the primer and glue are to be wet when assembling.

Intplm. said:

KC_Jones said:
@RickDelta

Based on your pics it appears you are letting the primer dry before assembly. That would be 100% wrong. The amount of time it is left open is enough to assemble 1 joint. No way you can prime and assemble 4 joints properly. You appear to be taking the time to use the primer, and yet doing it wrong basically negating the use of it.

It is pretty, but wrong.

Again, the primer and glue are to be wet when assembling.
Agreed.. to some extent. A good joint is one that doesn't leak and will not leak.

Try this. Use sand cloth instead of primer on PVC or CPVC. Prep the joint with the sand cloth as you would to clean copper for soldering. Removing the shine from the pipe and fitting. Do this in place of the primer. Now use the glue. Your joint will be true and sound.
In the early nineteen eighties new and out of trade school the company's I worked for did this. It blew my mind and it worked.
The above what @RickDelta does isn't necessarily wrong in letting the primer dry.
I use primer always now. When I left the earlier employment, primer was and is the go to from then on. Its a lot easier then using sand cloth to expose and soften the joint preparation.
Yes I know what the directions say from some manufacturers and yes I have heard all of the arguments but when you are on call late at night and not in your own vehicle. Some one didn't put the primer back in the truck or it spilled. Try it if you like, or don't, It's what was done by some when PVC was first coming into use.
My experience tells me that there can be six ways to do something and they all can be right.

I had talked to the manufacture (Oatley) and he said you have a five (5) minute working time. Does NOT have to be visibly wet! It seeps into the polymers and softens.

I would think if you had a wet puddle of primer on the surface of the pipe, it would only act to dilute the strength of the cement down.

In the masterbatch of the PVC polymer resin beads they add several additives to the mix. One of them is an additive to help the extruder push the PVC resin thru the forming die without surface face tearing of the extrusion. This is that "shiny" coat on the outside.

You'll see as you apply the primer, it just sits on the surface for the most part, still very liquid. After about three seconds, the primer starts to eat thru this resistant coating ..... but some areas remain un-affected.

This is evident of the primer "streaking" and not so uniform.

This is why you keep moving the applicator around and around the pipe to "work-in" the primer. At full surface break thru, you can see the primer turn to a complete uniformed matt finish with NO streaks. This is when 100% of the polymers are saturated with primer. At this point, the appearance is a dry mat finish and NOT shiny.

If you take a pin and press into the primed area, you will see it is in a "softened state" with NO liquid puddles of primer visible.

You now have five minutes to to apply cement and join fittings to pipe.

If you think about it, what your suggesting is really an "All-in-One" application!
Your mixing a full strength dose of "wet" primer and cement together ....... essentially at the same time.
I feel you are compromising the formulation attributes of the cement itself!

Primer is only to "prep" the polymer (soften)..... for the cement to make a stronger bond.

PVC Primer + Cement or All-in-One ?

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