Great discussion
Hi again,
Very, very few riggers dip wire before swaging, and they tend to work in warm climates, where the effects of corrosion are greatest. Since most cruisers spend at least some time there, we work to do what we can to limit corrosion. I came to embrace the Dipping School while working in the South, and seeing side-by-side examples, with the undipped ones failing, and the dipped ones not. I have also cut apart numerous swages, of all ages and from all climates, and I can tell you that they are far from impervious to water. I can also tell you that crevice corrosion is a bit more complex than the absence of oxygen; otherwise any piece of stainless would corrode from the inside out. A surface oxide coating is stainless's defense, and it can be replenished in the presence of oxygen. But if you exclude both air and corrosive elements, like saltwater, deterioration is largely arrested.
The next time you see vertical cracks on a swage, know that internal corrosion ówhich always causes the corroded material to expand ó is trying to blow the swage apart (horizontal cracks usually speak to fatigue, though there might also be a corrosion component). This usually, as noted above, happens close to the top of the swage, but I have some samples in my shop that are cracking near the bottom.
As for Hayn's instructions, all I can say is that they are roughly the same as Norseman's and Sta-lok's once were; leaving sealant out works pretty well in low-salt, low-temperature climates like England, for there you can count on plenty of fresh water to rinse out salt, and also count on that water evaporating, helping that oxide coating. But as Norseman and Sta-lok found out, and as I predict that Hayn will, Tropical waters are an entirely different story, with a lot more heat and salt, and a lot less fresh water rinsing. That's why we see a lot of internal corrosion in unsealed and inadequately sealed compression fittings, and none in properly sealed fittings.
Fair leads,
Brion Toss
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