OK. I haven't broken any bolts, but, the theory is that the portion of the
bolt below the line is deprived of oxygen. The same as a keel bolt. The
salt spray and humidity is there for the exposed portion. I don't think
it's a question of leaks.

Roger

http://home.insightbb.com/~derbyrm

"Glenn Ashmore" wrote in message
news:E4%8g.23482$iF3.17843@dukeread01...

"derbyrm" wrote
Don't use a stainless steel bolt (crevice corrosion). SS needs air.

Not necessarily true. Crevasse corrosion requires a lack of oxygen AND an
electrolyte like salt water. If the rail is properly bedded as
recommended the bolt will remain dry. If it does leak the damage to the
interior headliner will force rebedding long before the bolt is damaged to
any significant degree.