Jaquar – Rusted fittings All the jaquar fitting in my house are rusting. These were possibly the most expensive fittings at the time I bought, trusting that they are high quality- and SS, but all of them have black marks. Earlier i thought maybe… All the jaquar fitting in my house are rusting. These were possibly the most expensive fittings at the time I bought, trusting that they are high quality- and SS, but all of them have black marks. Earlier i thought maybe… Jaquar – Rusted fittings.