Bonding Epoxy to PVC PIPE

[michael pierzga]

Bonding epoxy to pvc pipe ? Flame treat or sandaper tooth ?

[CatBuilder]

I'm going to guess - never done it though:

sand paper, then the purple pre-treatment you normally use before the PVC pipe adhesive.

[TeddyDiver]

Doesn't bond any other way than mechanically so sanding, crossing grooves etc IMHO

[hoytedow]

The purple goo is a solvent for bonding PVC to PVC and would be useless with epoxy. Sand.

[CatBuilder]

Originally Posted by hoytedow

The purple goo is a solvent for bonding PVC to PVC and would be useless with epoxy. Sand.

Hoyt: So is that purple stuff part of the bonding? Had always thought it was one of those "etching solvents" used to prep the surface for a mechanical bond...

[hoytedow]

http://www.google.com/products/catal...ed=0CH4Q8wIwAQ

[CatBuilder]

Originally Posted by hoytedow

http://www.google.com/products/catal...ed=0CH4Q8wIwAQ

That's self priming cement.

I'm talking about the primer itself. Usually you have a purple solvent liquid you put on the PVC first, then when it dries (is complete with chemical etching?) you put the cement on.

The purple stuff is the primer.

Confused....

I do know that when you bond plastics using super glue or something like that, you need to first use a chemical etching solvent to get them to bond properly.

I had thought the purple stuff you use before the PVC cement was the chemical etching component of that particular bonding system. No?

[hoytedow]

Super glue is a mechanical bond. PVC is more of a weld with molecules from both pieces attaching to the other piece.

[hoytedow]

http://www.essortment.com/work-pvc-pipe-29909.html

"Be sure to purchase the appropriate glue. There is special glue for PVC, and it only works on PVC, and it really doesn't "glue" the PVC. Rather, it provides a chemical weld that cannot be unglued."

[CatBuilder]

http://www.restockit.com/pr-1-approx...22-55715).html


"Fast acting, hi-etch primer prepares the surfaces for superior bonding strength
Jim? PR1's purple color ensures easy visual check for complete coverage
Manufactured with only high quality 100% virgin materials
For use on both PVC and CPVC pipe, tubing and socket-type fittings"

"PVC primer prepares PVC surfaces for PVC cement welding---typically pipe fitting---via solvents that clean away dirt and debris from the PVC. The primer then dissolves/etches the top layer of each surface to make room for cement application. PVC primer comes in two primary forms---clear and with purple dye."

http://www.ehow.com/how_5883600_remo...-concrete.html

Hoyt, it's a chemical etching solvent, like you use to prep for bonding any other plastics with stuff like super glue. The chemical etching opens up the PVC and allows the cement to react with it.

You can see the etching as you apply it as you notice the surface of the PVC go from shiny/smooth to flat/etched.

[hoytedow]

It melts the surface with a solvent reactive for PVC for a chemical weld. Etch may be a poor choice of words.

[hoytedow]

Material safety data sheet: http://www.herchem.com/msds/MSDS70_purple_PVC_prim.pdf

[CatBuilder]

Originally Posted by hoytedow

It melts the surface with a solvent reactive for PVC for a chemical weld. Etch may be a poor choice of words.

Sorry, I call it that because that's what it's called in any scientific or industrial process. When you apply a solvent to a shiny, smooth surface to make it dull and roughed up for bonding with an adhesive, it's just called "chemical etching." I'd change it if I could.

[PAR]

PVC primer isn't going to help and in fact, will screw with the bond a little. The best way, which works fairly well, is to carbonize the surface with a torch after you've really toothed it up with an aggressive grit, then apply epoxy.

[CatBuilder]

Yeah, we did get off topic. ha ha ha