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Ted Mooney, P.E. RET
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Galvanized lag bolts and stainless railing
I'm putting up a stainless steel handrail, (on a beach house) that is being lagged to a roof deck with galvanized lag bolts and hot mopped over. Will I still get corrosion under the hot mop.
Dave AmbornMetal Worker - Ventura, California, USA
November 16, 2010
Hi, Dave. If it was my house I'd want stainless lag bolts. Who can say whether the bolts will last 2 years or 40 years? It's only guesswork. You have galvanic action from a relatively small zinc surface connected to a very large stainless surface, and you probably also have galvanic forces from a large amount of copper infused into the pressure treated wood. The hot mopping may work, or there may be porosity that keeps the bolts wet after a rain. The whole world is ganging up on those little cathodically active galvanized lag bolts. Poor things.
Regards,
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Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
November 16, 2010
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