Zinc Plated Fasteners

[Ernest T. Bass]

Hi all,

We were given a bunch of lag bolts that could be used on the exterior of the cabin that we will be building. I'm wondering if there is any way to keep them from rusting? They would be sheltered from the rain, and I wouldn't use them in PT lumber.. What if the heads were countersunk and the holes plugged or caulked over? Would they last?

Thanks!

[MountainDon]

So these are not plated? 

(subject line has zinc in it but you are concerned about rust...    makes me think they're not plated?)

[Ernest T. Bass]

Well, they're plated, but not "hot dipped galvanized". Just your typical lightly protected lag bolt, I guess. I don't think they're normally used outside, right?

[MountainDon]

I have used electroplated zinc bolts and lag screws for years when we were in the wood playground business. We had very few of those fasteners ever rust. Dry desert climate, but it does rain at times, enough to cause corrosion with non plated materials. Ditto for the standard galvanized Simpson brackets; we used plenty of hurricane ties in building shade roofs, for examples. No corrosion problems there either.

As I look out the window I can see a few electroplated bolts/washers/nuts that have been holding a couple fence panels in place for some 15+ years, maybe 20. They're still even shiny.

Hot dipped provides more protection for more severe climates. Hot dipped is also a requisite for ACQ treated wood.

So sheltered from direct rain I would think you should have no particular problems.

[Ernest T. Bass]

That's good news. How does Wolmanized wood treat fasteners compared to ACQ? Our lumberyard switched to this lumber this spring. Arch recommends the use of hot dipped in exterior applications, but is it risky not to?

[MountainDon]

We don't have the Wolman brand here. But IIRC I read someplace that hot dipped galvanized is recommended. And that's what you indicated. So I'd follow their recommendations for sure. 

Sometimes it makes a difference in the bolt diameter... not sure, don't build something on this "I think"... but I think 1/2" and larger is okay even if electroplated.

But I'd do exactly what the company states.

[ScottA]

I've used cheap plated lag bolts for gates before. They'll rust but the wood will probly rot out long before the bolts rust through.