I looked at the bolt pictures. The consensus on the TFP thread was that they were zinc plated. However, in another life, I've worked a great deal with stainless components and fastners -- those WERE stainless bolts. However, I learned long ago that much of the stainless used in pool biz is not the 316 or 304 grades I encountered in restaurant service. And, I have personally seen similar SS corrosion on stainless in short periods on non SWCG pools at low pH.

Of course, none of the threads on TFP were more than anecdotal in nature, so it's hard to say what it means, in the absence of a statistical comparison.

I think I need to revise the SWCG FAQ to reflect the warranty issue.

On another topic, did anyone call Keith at Rotometals?

Sean, has Horner ever looked at consulting with a corrosion engineer to work out cathodic protection for AG pools? It would be another product to sell.

Here are wikis for both anodic and cathodic protection:
http://en.wikipedia.org/wiki/Anodic_protection
http://en.wikipedia.org/wiki/Cathodic_protection

It's interesting that you can protect steel by making it EITHER a cathode or an anode in an e-c cell. Keith had said it can be tricky, but I gather for a well-defined system of known surface area and metal mass, it's pretty straightforward . . . IF you know what you are doing.

Ben