Hey! that PVC fittings looks ugly Why is there this ugly blue stuff all over it?
When viewed from the front it is possible to notice a white ring on the inside of some of the spouts. The white ring is the visible edge of the white PVC fitting. It's particularly noticeable on some of the shorter spouts like the Kepik.
Some of the fittings used for the spouts are available in black or gray. When possible, I provide these with the spout. Other fittings are just not manufactured this way. And, frankly, I can't affort to order 10,000 custom fittings made in black PVC. I'd never sell that many spouts. So, the next best option is to stain the ends a dark blue color.
The stain does not affect the plastic used to make the fitting. But, because the process used to glue PVC pipe melts the plastic, some of the blue stain might come off. DONT PANIC. It's nothing to worry about. The same thing happens when pipe that's been treated with purple primer is glued together.