Lamp post close to the sea 2

[mrcasper]

This may be a very newbie question but I have some lamp posts to install close to the sea.

Do I have to go with hot tipped galvanisd steel or would epoxy coated steel suffice?

Looking for a 2nd opinion, I'm cost driven

Thank You

 

[EdStainless]

How often do you want to replace it?
Do you get hurricanes? I have seen one storm blast all of the galv off of structures.

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Plymouth Tube

 

[mrcasper]

Well Trinidad has been spared alot of hurricanes.

We wont be responsible for the maintenance just the installation, hence the issue of cost.

 

[TomDOT]

Ed, Either that was a heck of a storm, or some pretty crappy adhesion of the galvanizing. You should be able to whack hot-dip with a hammer and stay intact.

 

[mrcasper]

Epoxy is the way to go?

 

[TomDOT]

Epoxy is typically more susceptible to installation damage, and is more likely to rust at those damaged spots (before the install is signed off.)

Depends how much you trust the installers.

 

[EdStainless]

Tom, a little sand in the blown surf and you wet grind things fast.
Used to go to Wrightsville Beach, nothing facing the ocean has any galv left on it.

Yes, if the install will be done well then epoxy is the way to go.

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Plymouth Tube

 

[TomDOT]

Ed: Galv does corrode pretty quickly in the seaside environment - but so do a lot of materials. Continuous-wet and salt are particularly bad, thus the ocean-facing side corroding faster due to salt spray (which can be carried for miles.)* Durability is directly related to zinc thickness. Still corrodes much more slowly than exposed steel.

Also - once you get through the pure-zinc "Eta" layer of galvanizing, you will get rust staining/discoloration as the iron alloy layers start to corrode. Iron oxides are a pretty powerful pigment. However, you still have most of the corrosion resistance of galvanizing (slower corrosion rate) until you lose the "Gamma" alloy layer and get down to pure iron/steel.

* Sandy beaches actually have more salt spray carried further, because the average particle size is smaller. Rocky beaches tend to have larger droplets, which fall out of the air faster.

 

[mrcasper]

Thank You Gentlemen

 

[stevenal]

The epoxy will flake off, the zinc will not. Both can be attacked by wind driven sand. This coastal resident would chose the galvanized product. You won't be responsible for maintenance, but won't your client be?

 

[mrcasper]

I'm thinking in the long term, the maintenance of the epoxy would be more practical to do in situ.

Received a few quotes and the price for hot tip is 4 times as much as epoxy, meaning after the cost for 4 repairs, the cost of maintenance compared to hot tip would be an issue

 

[TomDOT]

Field cleaning and painting installed structures/items is noticeably more expensive than an initial shop painting.

 

[Metaljon]

Neither galvanizing or epoxy will work in isolation. If you want it to last in a severe marine environment then it is essential to do hot dip galvanizing and then prime and apply epoxy paint coatings.

http://nz.linkedin.com/pub/jonathan-smith/39/25/589