steel gate post coating ...

[iron_giant]

Fellow mudders,

I am building a small enclosure with a custom gate and would like to use a steel 4x4 post to support the gate. The post will have to be embedded in and bolted to a concrete driveway and I am wondering what would be the best way to keep the embedded portion from rusting. I have been considering having it zinc plated but thought I'd ask here for any other ideas.

Thank you much,

David

 

[bkfj40]

galvanize it or use stainless steel if you want it to last for 100+ years

however, uncoated steel put into concrete and a thicker wall tube (HSS) will still last a long, long time....


bk

 

[KLF]

The steel inside the concrete shouldn't be a problem (think of all the buildings with all that uncoated reinforcement steel embedded in them). The problem will be right where the steel exits the concrete, water will puddle there when it rains and free calcium will leach out of the concrete and corrode the steel. One day it will just snap right off.

Without seeing the installation, I suggest things like a thick coating of a rubberized material right at this point (like roofing patch material), a strong epoxy paint, and slope the top of the concrete at this point so water can't sit there. Maybe a bead of silicone right at the joint too.

 

[mminter1973]

I built a custom 2 leaf gate with 6x6x3/8" posts then painted them with epoxy primer and then single stage PPG. Looks like a showroom paint job. I am sure 4x4x1/4" posts would have been just as well.

I just bought 2, 20' sticks of 4x4x1/4" for another gate job, seems my first gate was pretty popular! and it was $440 so get ready to bend over!

 

[haystax]

The most bulletproof way of preventing the metal to concrete surfaces from failing is also the least aesthetically pleasing - sleeve the post with PVC and isolate the post from the slab, then fill the PVC sleeve with tar or lots of silicone. Ugly, but not as ugly as trying to fix a line of posts rusted off in a slab.

Wrapping the post with a bitumen flashing membrane designed for deck hangers and such should work fine for your intended use.