Quote:
Originally Posted by Brian Duff
thats on my list
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I have one of those lists too.
Please forgive me, but do you mind if I ask one final follow up question?
I agree with this;
Quote:
Originally Posted by Brian Duff
The observations i have made about the failures of wire tecknic or kearny drawn swages as opposed to rotatry swages have been a result of the crease, fold, or ridge left by the rollers - this site has been the beginig of corrosion on the fitting by my observation.
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But I can't truthfully say that I have noticed that the rotary swages last longer. I do lots of inspections, as I am sure you do. I live in Florida and I would say that the average life span of a rig is between 12 and 15 years. I really don't think that one method of swaging has shown to have a longer life than the other. At least here.
The die marks from Kearny or roller swagers sometime will look like a swage crack, but often aren't. Many times, upon closer inspection, they are just little creases, like scratches in the surface that start showing surface corrosion first.
I think that I read earlier somewhere in this thread or the one we were linked to, about swage cracks starting on the outside and moving inward. That doesn't make sense to me.
In my experience, stainless always corrodes where it doesn't get ventilation. Where do chainplates or u-bolts usually fail?
My understanding has always been that as the corrosion builds in the interior of a swage, it acts similar to a rusting piece of re-bar in a brick wall. Swelling with the corrosion (rust) until the internal pressure cracks the wall. Or like a stainless bearing race in an aluminum housing. The corrosion builds up and pushes on the outside of the races thereby increasing pressure on the balls until it seizes up the bearing.
My question is this; Are you convinced that swage cracks show up earlier in a swage made on a good roller swager than they do on a good rotary?