reconstitute PVC cement

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.

Reply to
Deodiaus
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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'

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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.

Reply to
nestork

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!

Reply to
Ed Pawlowski

+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.

Reply to
trader_4

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

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Reply to
HerHusband

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

Reply to
Frank

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'

formatting link

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.

Reply to
WW

Bob,

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

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Reply to
HerHusband

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

Reply to
Deodiaus

ent which got wet. THis is probably hard as it involves a complex chemical reaction with water which might be very difficult to drive backwards.

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 pip e and the fitting. Some dissolved PVC is also pre-dissolved in the cement. After joining the two parts, the solvent dissipates (a) by evaporating an d (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 m uch solvent diffusing into the plastic softens it and causes it to swell an d weaken.

Reply to
jim4ye

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

Reply to
Clare Snyder

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.

Reply to
Bondprint

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