JBarca wrote:
Do you have a more in focus close up of the end of the weld on the 120 V pocket where the crack occurred? I'm looking for that exact location to see how close it is to the toe of the weld. It looks like it is exactly right at the end of it which fits one pattern of thermal expansion stresses.
Jeeze, so demanding ;) Okay I went and cut out a cross section & polished so you can see both sides of the crack. I couldn't get it to show in the pix, so I bent the element pocket slightly away from the boiler to open the crack. Even then this type of shot with my camera is tricky as it does not have a manual focus. Out of about 50 pix I got 2 that aren't bad. Yes, it is at the toe of the weld. As you can see it starts right where the weld was terminated and curves around kind of a "U" shape. The crack isn't as big on the inside of the boiler tube. I'm guessing it started on the exterior weld and probably took a couple years and many heating cycles to progress into the inside surface of the boiler. Of the failures I've seen, they have almost all been coaches owned by full timers that ran the refer constantly on 120v electric. The average time frame for a failure to occur (on the ones I've seen) is between 2-3 years of using in this manner. I hope these pix help explain things better. Tim
