Q: Which zipper can survive chlorinated swimwear use?
Swimwear needs acetal or plastic molded teeth with a plastic slider and a corrosion-resistant spring, in size 3 or 4.5 depending on the garment. A chest zip on a rash guard or a short front zip on a swim top is normally closed-end; a full-front surf suit uses size 5 plastic with a locking slider. Metal teeth and metal springs are the wrong choice, because chlorine and salt water attack the plating and leave rust marks that will not wash out of the fabric.
- Size 3 or 4.5 acetal teeth, plastic slider.
- Closed-end for chest zips; size 5 for a full surf-suit front.
- Rinse the garment in fresh water after every use.
The common pitfall is a standard metal zip chosen for looks, which corrodes within a season and stains the surrounding panel. The second is ignoring water uptake: the tape absorbs water, the zip tightens when wet and the slider becomes hard to move. Sunscreen and sand also jam unprotected teeth, so specify a smooth coated tape and avoid open coil on any zip that sits near the sand.