What kind of problems can you have with stainless steel?
In most cases stainless steel is maintenance free and will last for years. But it has some
drawbacks, of course. It has a low modulus of elasticity, which means it doesn’t bend and flex
well. It develops microscopic stress cracks, which are very hard to spot, and have a tendency
to cause sudden, unexpected total failure of the part. The other problem is that stainless
steel protects itself by oxidizing its surface. When deprived of oxygen, the oxidation cannot
occur and the ferrous component of the alloy begins to rust. This is so called crevice
corrosion. Typically found where a nut has covered the thread of a bolt, or a bolt passing
through a wooden bulkhead. The SS wire inside a swaged fitting. Behind a chainplate, or
inside a stress crack. The result looks like some kind super-rat has been gnawing the metal.
You have to know where to look and have a magnifying glass or microscope handy. The
magna-fluxing of suspect pieces can show cracks imperceptible to even a strong lens.
How long will the rigging last on my sailboat? Amount and type of use, length of season, and
climate will dictate.
I will perform a cursory exam of rigging at the deck level, but age and signs of stress or
crevice corrosion will lead me to recommend a thorough examination of all the standing
rigging. I offer magna-fluxing of any component suspect of stress cracks. This would include
swage fittings, chainplates, turnbuckles, tangs, prop shafts, propellers or any metal,
(especially stainless), that takes a lot of stress.
In most cases stainless steel is maintenance free and will last for years. But it has some
drawbacks, of course. It has a low modulus of elasticity, which means it doesn’t bend and flex
well. It develops microscopic stress cracks, which are very hard to spot, and have a tendency
to cause sudden, unexpected total failure of the part. The other problem is that stainless
steel protects itself by oxidizing its surface. When deprived of oxygen, the oxidation cannot
occur and the ferrous component of the alloy begins to rust. This is so called crevice
corrosion. Typically found where a nut has covered the thread of a bolt, or a bolt passing
through a wooden bulkhead. The SS wire inside a swaged fitting. Behind a chainplate, or
inside a stress crack. The result looks like some kind super-rat has been gnawing the metal.
You have to know where to look and have a magnifying glass or microscope handy. The
magna-fluxing of suspect pieces can show cracks imperceptible to even a strong lens.
How long will the rigging last on my sailboat? Amount and type of use, length of season, and
climate will dictate.
I will perform a cursory exam of rigging at the deck level, but age and signs of stress or
crevice corrosion will lead me to recommend a thorough examination of all the standing
rigging. I offer magna-fluxing of any component suspect of stress cracks. This would include
swage fittings, chainplates, turnbuckles, tangs, prop shafts, propellers or any metal,
(especially stainless), that takes a lot of stress.
From the Surveyor's Notebook
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