Pipe Cleaner {insert logical operator} Clear Primer

[mark.f]

The age old debate is back.

Recently, I have been hearing a lot about primers and cements, due to the new VOC restrictions in places like California.

Well, just recently, I have had a lot of interest in whether or not cleaner was a substitute for a primer. Well, not exactly a substitute, but a reasonable replacement.

Well, just for the record, the "Handy-Packs" sold by Oatey, of the LO-VOC variety, which sell in my area, do not include cement and purple primer anymore. They contain LO-VOC cement and cleaner.

So, naturally, I was interested in what type of pipe this was used to join, and it is to join water lines, as well as DWV, etc...

So, not that it really means anything at all for the purposes of this discussion, I inquired, to two sources, whether it would be theoretically safe to use cleaner in lieu of primer. One source was my local hardware store owner. I know these guys don't get a lot of credit around here, but he told me that mostly everybody who came through his store used the cleaner and cement, and told me that it was much more important to have a clean joint than anything else you could do. Kind of odd to ask this of a man I have bought tons of PVC fittings from before, but whatever.

Second source was my brother, a licensed plumber here in Louisiana. He, of course, said that it was necessary to use a listed purple primer on all joints.

So, I figure it's good to include a list of all respected members who have used cleaner instead of primer for their projects. Not that it means anything, again, but for the hell of it.

~ KlugeBoy
~SMOMW
~starman

I'm sure there are more, but these are the ones I have seen to use it.

Now, all of this really doesn't prove anything, but I'm willing to start the debate again. Also, I might decide to call or email a few of the chem companies about this issue tomorrow during business hours, but I really doubt I'll get a good response.

What do you guys think? I know this topic has been beaten to death, but try to be civil.

Code: Select all

DISCLAIMER: I do not suggest using cleaner as a substitute for primer, especially for pneumatic applications. This is just a "theoretical, maybe this will work" thread. As an analogy, you wouldn't go out pressurize a piece of 1/2" SCH-40 PVC to 600 PSI of air because, theoretically, it should hold. Discussion ONLY.

[inonickname]

Well I'm not really sure. A primer is the safest and most guaranteed option; but a primer is usually something such as acetone with several chemicals blended in; acetone is a common PVC pipe cleaner.

I have used acetone (pure) in place of primer before and when tested it did not fail (110 psi).

If you're concerned about safety, go for the primer.

[jook13]

It is very tough to find clear pvc primer. The local plumbing stores employees here cock their head sideways and state "it only comes in purple dude...". It seems to me that the primer simply softens the pipe, so if the cleaner does that, then it works.

[mark.f]

From Oatey's web site, cleaner is not as aggressive as primer, but neither is primer/cleaner. The cleaner does everything the primer does, except they claim that primer softens the PVC pipe for the cement to penetrate more effectively. Personally, I have seen cleaner do the same thing, but that IS SUBJECTIVE.

And clear primer is very difficult to come by these days. You can order it from Launchpotatoes or another spudgunning site, but the industrial supply catalogs I usually look at have stopped carrying it because of new regulations.

You can still find it from places that sell fittings and pipe for aquariums (especially ones that sell clear pipe and fittings).

I just emailed Oatey about it, but I'm not sure I'll get a response. I'll probably send the email to a few other manufacturers as well (Harveys, Weld-On, etc.).

[Biopyro]

In the UK you can't get "primer" purpl or otherwise. It is all called cleaner and is usually MEK based. Both chemicals penetrate the PVC and soften it, which is the job you want it to do.
On the UKSGC I can think of 4 large (even by US standards ) cannons, which will all have used cleaner, and are all used around 130+PSI, and I use 140psi in my PVC 40mm piston cannon.
Really, it does the same job, and as long as you follow the instructions you'll be fine, although whether it is less agressive, I'm not sure. Is there any way you can compare the ingredients?
I have heard before that the purple is only added so that building contracors cannot get away with not using it, because it's so obvious.

[mark.f]

Well, I got my reply back from Oatey.

Mark, by all means switch to the clear cleaner. the purple primer is thinner than water and almost impossible to apply neatly. As far as the cement is concerned use a thicker clear cement which would be less runny. I suggest the Medium Clear PVC cement. Good Luck with your application.



Rob Emery, Product Application Specialist

I'm pretty sure this has been asked about a thousand times, but I could
find no definite answers.

I am working on an art project which requires pressurized water from a
hose bib.

I need to run multiple lines, and plastic pipe solvent-welded together
is the easiest way to go, for many reasons.

Only thing is, even with the fittings and pipe taped off and protected
from spills, I still cannot get a good-looking joint with listed purple
primer and regular-body cement. I know you probably don't get a lot of
questions concerning this detail (I've done many plumbing jobs before
and usually spill the stuff all over what I'm working on), so bear with
me. I've gone so far as to tape off the pipe, outside of the fitting,
the end of the fitting by taping over it and trimming with a razor, and
I still get purple stains around the joint.

None of this has to conform to any official building or plumbing code,
and the piping will not hold any critical materials, so is it possible
to "switch out" the purple primer I can get locally with the clear
cleaner (non LO-VOC variety), and still have a functional joint? I plan
on cleaning the mating surfaces before-hand with soap and water, rinsing
and drying completely, using multiple passes with the cleaner to further
clean and soften the pipe, and then applying cement and completing the
joint.

I have measured the water pressure from the hose bib I will be using,
and got a reading that peaked at around 100 PSIG. Do you think that the
aforementioned method of solvent welding the joints will be leak-free
and hold? Most of my local sources I have asked have said "yes", but I
figured it would be great to get that straight from the horse's mouth. I
have, until recently, ordered a listed clear primer for my jobs when
required, but lately, with the new regulations put in place everywhere,
most of the places I have looked do not carry it anymore.

I know this is really an off-the-wall question, and it's not really what
you guys answer most of the time, but I would appreciate it very greatly
if you could get back to me with some closure. If you cannot answer the
question due to liabilities or other things of that nature, I completely
understand.

~Mark F.
A math major forced into an art project.

Quite possibly the greatest work of fiction since Victor Hugo came onto the scene, but there you have it. Apparently they're okay with telling people to use clear cleaner for pressurized water applications.

[inonickname]

MEK is one of the prime chemicals in paint thinner I believe, and it penetrates quicker than acetone would (I reckon it's more aggressive). That said, I reckon acetone works just as well is you do around 2 coats and give it time to penetrate.

That said, it'll do the same job as primer, except with the lack of color take care that you don't miss a part.

[mark.f]

Actually, the active solvent in pipe primers, cement, and cleaner is Tetrahydrofuran. It is this solvent which does the best job at dissolving PVC.

[inonickname]

Alright, I stand corrected. How aggressive is it compared with acetone, paint thinner etc?

I have no problems with acetone, brings it up nicely but you do need a little more patience

[mark.f]

It's pretty good at what it does. People have used it to thin out their cements after they sit for a while, which contain PVC polymers.

[jimmy101]

From spudwiki

Comparison of typical compositions for PVC Cleaner, <a href="/spud_wiki/index.php/Primer" title="Primer">PVC Purple Primer</a> and <a href="/spud_wiki/index.php/PVC_Glue" title="PVC Glue">PVC Glue</a>.
<table border="1"><tr><td> Ingredient </td><td> Percentage in
PVC Cleaner </td><td> Percentage in
PVC Purple Primer </td><td> Percentage in
PVC Glue</td></tr><tr><td> PVC Resin</td><td align="center"> --</td><td align="center"> --</td><td align="center"> 10 - 14%</td></tr><tr><td> Methyl Ethyl Ketone (MEK)</td><td align="center"> 85 - 95%</td><td align="center"> 13 - 17%</td><td align="center"> 40 - 55%</td></tr><tr><td> Acetone
</td><td align="center"> 1 - 10%</td><td align="center"> 70 - 80%</td><td align="center"> 0 - 5%</td></tr><tr><td> Cyclohexanone</td><td align="center"> --</td><td align="center"> 5 - 10%</td><td align="center"> 5 - 10%</td></tr><tr><td> Tetrahydrofuran</td><td align="center"> --</td><td align="center"> 1 - 5%</td><td align="center"> 25 - 40%</td></tr><tr><td> Dyes
</td><td align="center"> --</td><td align="center"> <2%</td><td align="center"> --</td></tr></table>The values in the table above are based on the products from Oatey.

I suspect there is really no significant difference between acetone, MEK and THF (tetrahydrofuran) in terms of their ability to soften and/or dissolve PVC.

The actual choice of which (and how much) of each solvent used in cleaner vs. primer vs. glue probably has more to do with how quickly they evaporate. For cleaning you want the solvent to evaporate quickly. For priming you want it to hang around long enough for the glue to be applied.

Boiling Points:
Acetone 56C (133F)
THF 66C (151F)
MEK 80C (175F)

[starman]

Well the last time I brought this up about a year ago, I got the dog-pile treatment.

I have found that the cleaner doesn't dig in quite as much as the primer, but it does dig, especially for about 2 minutes or so...the primer softens a little longer, maybe 5 minutes. Both will eventually reharden if not cemented relatively soon. However, keep in mind that it is the cement that ultimately does the glueing. What you want to make sure of primarily is that the surfaces are free of oils, moisture and dirt that can cause voids in the joint...and secondarily to roughen the surfaces slightly to allow the most surface area to be cemented. Both cleaner and primer perform this function to one degree or the other.

I personally use cleaner for all PVC priming spudgun jobs, but if a noob asks, I've been telling them to use the purple stuff.

[mark.f]

I've made a few joints today using the cleaner.

What I did was wash the fittings and pipe with soap and water, drying completely, and then going on to solvent weld.

I then did two consecutive coats of cleaner on the pipe, then two in the fitting, another coat on the pipe, a coat in the fitting, and a final coat on the pipe before applying a coat of glue to the pipe, then in the fitting, and lastly on the pipe again.

We'll see how they hold up.

[Biopyro]

You can make a joint without primer or cleaner, but it won;t be as good as with. If you're expecting the fittings to pop off under pressure, they won't. I think it will be hard to objectively compare the joint to one made with primer.

[starman]

We'll see how they hold up.

There is no question about the joints holding up. It's likely you don't have access to an air pressure source strong enough to find the limits of your welds.