Carpentry and Woodworking - Zinc vs. Galvanized lag screws

I'm building a retaining wall for the garden, using 4x4 pressure treated timbers. They'll be stacked 3 high, so I want to use screws to hold them together.

I did the Home Depot stumble, and was presented with zinc and galvanized lag screws. Is there a reason to choose one over the other? I'd like to avoid rust.

Thanks!

Hi Munk,

You'll want to use galvanized for rust protection.

Good luck

Uh...guys......to "galvanize" something is to coat it with zinc.

There are two methods:

"Electroplated", which makes a thin, but shiny coat of zinc on the suface....and doesn't last very long when exposed or in treated lumber.....

and "Hot Dipped", which makes more of a dull silver color and a rougher finish ( picture dipping something in hot wax ), but the zinc is a LOT thicker and will resist rusting of the underlying steel much longer.

Go with the hot dip if you want longer term protection.

and actually zinc "rusts" too.....it's just a white rust that isn't as noticeable as iron red rust.

The screws may hold since you're only three high.

But I use rebar (a ft to 18 inches in length), pre-drill and pound them in. They don't move!!
And they are considerably cheaper than any large screws..


fred

Hi Munk,

Tn...Andy is correct. However, when you go into a typical store such as Lowes or Home Depot, you are presented with what the layman refers to as "zinc" (plated) or "galvanized" (hot dipped). Go for the latter and you'll be getting what Tn...Andy is calling for...the product with the rough, dull gray/white appearance. It is more expensive, but well worth the difference if they are to be exposed to weather, or in particular, CCA treated lumber.

Good luck,
Randy