Polymer

Polymer skimmer lids exist chiefly as a convenience option for sites where electrical bonding cannot be arranged; they come with a five‑year manufacturer’s warranty—mirroring the way chlorine and UV quickly embrittle poolside plastics—whereas HIDE’s 316 L stainless lids are backed for ten years internationally and up to twenty years in Australia and New Zealand. (skimmerlids.com.au, info.skimmerlids.com.au, skimmerlids.com.au) Bonding the stainless lid is straightforward during construction—the tray is supplied with a pre‑drilled earthing lug and, when connected to the pool’s equipotential bonding system, meets industry safety guidelines for conductive fittings around water. (info.skimmerlids.com.au) Choose stainless steel for its enduring safety and extended warranty; reserve the polymer cover only when bonding truly isn’t possible, accepting its shorter service life as the trade‑off. (skimmerlids.com.au, info.skimmerlids.com.au)

HIDE offers polymer covers for 20 mm and 30 mm inlays, available in three contemporary tones—Ash, Bone and Charcoal—to harmonise seamlessly with surrounding tile and grout colours. Read more

How pool chemistry undermines polymer lids

Pool chemicals are unforgiving on plastics. Oxidising sanitisers (chlorine and sodium‑hypochlorite), low‑pH acid washes and relentless UV all attack polymer chains, bleaching colour, stripping UV stabilisers, embrittling the material and setting up stress‑crack failure. The result is the familiar story of yellowed, brittle lids and bubble‑covers that flake into the water after only a handful of seasons—problems 316 L stainless simply avoids.

1  Chlorine & sodium‑hypochlorite: oxidative chain‑scission

• Strong oxidisers break carbon‑to‑carbon bonds in polyolefins; bleach (NaOCl) triggers environmental stress cracking in both PE and PP, reducing molecular weight and strength. (LyondellBasell, CDR Pumps (UK) Ltd)

• Failures start at corners and thin sections, then spider‑web through the part. (Curbell Plastics)

• Once the antioxidant package is used up, the covers turn chalk‑white and the bubbles crumble. (Daisy Pool Covers, Plastipack Limited)

2  UV + chemical synergy

• UV radiation creates free radicals; chlorine accelerates the reaction, so plastics chalk, fade and crack far faster pool‑side than in normal outdoor use. (Cole-Parmer, SCIRP)

• Combined UV/aqueous exposure produces deeper surface fissures than either factor alone. (ScienceDirect)

3  Acid cleaners and low‑pH shocks

• Muriatic (hydrochloric) acid, often used to clean stone or drop pH, lowers water pH well below 7, making it corrosive to vinyl liners and weakening plastic fittings; plastics become brittle and ladder rungs snap. (My Perfect Pool, Pool Research, Welcome to Poolsmith Technologies)

• Acid splashes can etch polymer lids permanently, just as they strip stainless of its passive film.

4  Thermal & mechanical side‑effects

Polymer coefficients of thermal expansion (≈ 80 µm m‑¹ K‑¹ for PP) are five times that of 316 L (16 µm m‑¹ K‑¹). Repeated 20‑40 °C cycles around a pool loosen grouts and warp covers. (Matmake)

Real‑world evidence of polymer failure

Why 316 L stainless wins

• Resists oxidisers – The molybdenum‑rich passive film shrugs off chlorides and hypochlorite. (Aquatics International)

• Handles acids better – Brief acid contact may tarnish the surface, but it does not embrittle the metal; a quick neutral rinse restores protection.

• UV‑proof – Photons cannot break metallic bonds, so there is no fading or chalking.

• Dimensional stability – Low thermal expansion keeps grout lines tight and lids flat.

• Service life – Decades on super‑yachts translate to decades at the pool.

Look after your stainless steel, and it will look after you for decades.