Plastic identification

[BradC]

Ok so this is a bit left field.

I have a 56 year old pool which has some seam leaks in the skimmer. The skimmer is likely to be either ABS or PVC and I don’t know how to tell which. I’ve patched it twice in the last 16 years by dremelling out the seam and filling it with 24 hour Araldite. This works to keep the water in, but this particular leak is letting air in under vacuum. I could really do wth the right adhesive rather than a generic mechanical epoxy but to do that I need to know what the plastic actually is. Araldite works under pressure, but doesn’t seem to hold that well under vacuum and constant immersion.

I’ve spent a few hours on the search engines but come up blank. Over the years I’ve seen some pretty impressive technical knowledge here, so I thought I might ask the question and leverage the global experience here.

[kosine]

Assuming it's outdoors, PVC is generally a better material, and if the pool is chlorinated that would also suggest PVC.

You could try tapping it with metal implement (like a screwdriver). PVC is denser than ABS and will sound duller. ABS is a bit more tinny. If you've got anything lying around known to be made of the two, you should be able to hear the difference.

[Kleinstein]

One could test for the chlorine content in PVC. The test is using a hot, clean copper wire to melt / burn a little of the plastics and than hold the wire in a blue glass / alcohol flame. If halogenes are present in the plastics it would cause some green flame color from forming somewaht volative CuCl.

[u666sa]

For a pool skimmer installed in Australia in the 1970s, it is more likely to be made from PVC than ABS. This is because:
PVC had strong market penetration: The 1970s saw spectacular growth and market dominance for PVC pipe systems in Australia, particularly for sewer, waste, and vent (SWV) applications.
ABS was not widely used for pool plumbing: While ABS plastic existed, there is no evidence suggesting widespread use in Australian pool plumbing during this period. American manufacturers did produce ABS pressure fittings in the 1960s and 70s, but this was not common practice in Australia.
How to identify if your skimmer is PVC or ABS
To verify the material of your pool skimmer, you can check for markings or perform a simple, discreet test.
Check the fittings
Color of the fittings: In the 1960s and 1970s, many PVC DWV (drain, waste, vent) fittings were beige or grey before white became standard in the late 1970s. White is the most common color for both modern PVC and ABS fittings.
Manufacturer markings: Older fittings might have the manufacturer's name, such as "Vinidex," which was founded in 1960 and manufactured PVC conduit from the start.
Check the glue: PVC cement typically has a yellowish, clear, or bluish tint, whereas ABS cement is often black.
Physical properties
Odor when sanded: Scraping or sanding a hidden part of the pipe and then smelling it is a reliable test. ABS has a distinct odor similar to burnt plastic, while PVC is less pungent and more chemical-smelling.
Flexibility and impact resistance: ABS is generally softer and more flexible than PVC, and more durable in colder temperatures. For a 1970s installation, this difference may be negligible if the skimmer is still in good conditio

[BradC]

Thanks all. Sounds like it would be PVC. The halide test is a great idea. As I have to scrape the seam line to expose fresh plastic for gluing I'll wind up with a fair little pile of shavings, so I'll give that a go on the weekend.

[jpanhalt]

Flame tests can be useful and most people have what is needed to do them.  When at a loss, take a sliver of real ABS and PVC to compare.  Then dremel a little from the damaged area and test that.  This site describes them:

https://www.boedeker.com/Technical-Resources/Technical-Library/Plastic-Identification?srsltid=AfmBOooPs53iwPiLYnGKBr-33G8aWtUZ4vxztIZKjBi_iHfjcHoAUBKu

[magic]

ABS is instantly softened by acetone.

[BradC]

To to finish this, I did the flame test and it's PVC. I did test some ABS also just to be sure.

I ended up using a methacrylate 2 pack adhesive to bond it and, winner! Thanks for the advice.