reconstitute PVC cement

[Deodiaus]

Has any modern day alchemists tried and succeeded to reconstitute PVC cement which got wet. THis is probably hard as it involves a complex chemical reaction with water which might be very difficult to drive backwards.
But then, I am sure that I am not the only one who has had this happen.

[nestork]

No, there's no complex chemistry to it.

This web page offers a link to the MSDS form for Oatey Regular Clear PVC
Cement:

'PVC Regular Clear Cement | Plastic Pipe Cements & Primers | Oatey'
(http://tinyurl.com/lrwv6vu)

If you click on the MSDS link, you'll find that PVC cement consists of a
mixture of solvents, typically:

15 to 40 percent tetrohydrofuran - Tetrohydrofuran is a solvent that
dissolves PVC

10 to 20 percent PVC resin

10 to 20 percent acetone - which is what nail polish remover is

10 to 30 percent Methyl Ethyl Ketone, which is chemically very similar
to acetone, and

7 to 13 percent cyclohexanone, which is basically benzene with an oxygen
double bonded to one of the carbon atoms.

Really, the tetrohydrofuran just dissolves the PVC, and as it and the
other solvents evaporate from the joint the plastic reforms with the new
PVC resins being incorporated into the joint. Physically, it's very
much like melting ice and then letting it refreeze.

It's the tetrohydrofuran that does all the work here, and any place that
makes PVC windows will have some they can sell you or at least know
where you can get it. If your PVC cement is just thick rather than
hard, I would just add some tetrohydrofuran to thin it out. If it's
hard, what you have is a hunk of PVC plastic, and you may as well chuck
that in the garbage.




--
nestork

[Ed Pawlowski]

On Sun, 8 Jun 2014 14:27:49 -0700 (PDT), Deodiaus <deod...@yahoo.com>
wrote:

>Has any modern day alchemists tried and succeeded to reconstitute PVC cement which got wet. THis is probably hard as it involves a complex chemical reaction with water which might be very difficult to drive backwards.
>But then, I am sure that I am not the only one who has had this happen.

Once it has lost key components, it is not a matter of just adding
something back in. Many products, once cure, are not reversible. Toss
it and you can be sure with fresh cement you will have proper joints
too!

[trader_4]

+1

Maybe it's just me, but I've never had PVC cement get water in it.
And I've also never had a large enough can of it where it's even worth
contemplating trying to resurrect it if it did.

[HerHusband]

> Has any modern day alchemists tried and succeeded to reconstitute PVC
> cement which got wet.

If your cement is wet or gelled, it would be best to throw it out and buy
fresh cement. Do you really want to risk a faulty plumbing connection over
a few dollars for new cement?

Since PVC tends to gel once it has been opened, I prefer to buy the
smallest cans I can find. That way I can use what I need on that project
and throw the remainder of the can away. Then I'll have a fresh new can for
the next project.

The only time I buy larger cans is when I have a major project like
plumbing an entire house. Basically when I know I'm going to use more than
one of the smaller cans.

Anthony Watson
www.watsondiy.com
www.mountainsoftware.com

[Frank]

I gave him a similar answer in sci.chem so I guess he did not like it
and and came here ;)

[WW]

"nestork" wrote in message news:nestork...@diybanter.com...

Yesterday I needed my PVC cement and found it was a soft gel condition.
Added some MEK let it set and it liquefied and worked OK. Saved me a 6 mile
trip to the hardware. WW

[Bob F]

Would storing the cans upside down make them last longer?

[HerHusband]

Bob,

>> Since PVC tends to gel once it has been opened, I prefer to buy the
>> smallest cans I can find. That way I can use what I need on that
>> project and throw the remainder of the can away. Then I'll have a
>> fresh new can for the next project.

> Would storing the cans upside down make them last longer?

I'm no chemist, but I wouldn't think it would make any difference. Once the
can is opened, the cement has already started reacting with the air. When
you put the lid back on, the air is trapped in the can regardless of which
orientation you put it in.

In my experience, the entire can turns to jelly evenly. It's not like it
forms a skin on top or anything.

Of course, it would be any easy experiment to open a couple of small cans
for 15-30 minutes, dipping the wand in and out several times to stir it up
as you normally would. Then seal them up again, storing one upright and the
other upside down. Wait a couple months then check them both to see if
there's any difference. Maybe you'll prove me wrong. :)

Anthony Watson
www.watsondiy.com
www.mountainsoftware.com

[Deodiaus]

Thanks for your reply. I posted in both places as I did not know which had the more knowledgeable people.

[jim...@gmail.com]

On Sunday, June 8, 2014 at 5:27:49 PM UTC-4, Deodiaus wrote:
> Has any modern day alchemists tried and succeeded to reconstitute PVC cement which got wet. THis is probably hard as it involves a complex chemical reaction with water which might be very difficult to drive backwards.
> But then, I am sure that I am not the only one who has had this happen.

No chemical reaction is involved at all. It is a purely physical process. The solvents in the cement dissolve a thin layer of the surface of the pipe and the fitting. Some dissolved PVC is also pre-dissolved in the cement. After joining the two parts, the solvent dissipates (a) by evaporating and (b) by diffusing further into the plastic. It's the latter process that they want you to limit by not letting the primer or cement puddle, as too much solvent diffusing into the plastic softens it and causes it to swell and weaken.

[Clare Snyder]

That is true in normal conditions. Addition of water MAY make the
glue irretrievable.

[Bondprint]

I have had success adding acetone (fingernail polish remover) to jelled PVC cement, but I don't use it for plumbing. Rather, I build stuff out of PVC and my reconstituted cement holds together just fine.

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