On 6/8/2014 8:38 PM, nestork wrote:
Deodiaus;3246045 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, 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.




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