How deep does galvanizing go?

[98TJ10]

Just unwrapped a brand new Faber HP100 and it looks like it’s missing some galvanizing around the neck. Is this just the surface coat or something I should be worried about?

 

[Wookie]

The hot-dipped galvanized finish is heavy duty "industrial grade", with minor cosmetic imperfections that in no way impacts their durability or function.

For example, the ASTM A123 specification standard range for hot-dip galvanizing is 1.4 to 3.9 mils. As long as the thickness is in that range, then your material will have the best corrosion protection.

 

[PACKRMAN]

Hot dip galvanize is a surface coating. It does not penetrate the base material like anodize on aluminum. There are solutions that will give a color indication if steel is present, copper sulfate etc. Of course you could always get it wet and see if it starts to rust. Personally, that appears to be a stain. I would try to rub it with some scotchbrite or steel wool and see if it goes away.

 

[rjack321]

1 mil = 0.001" or 0.025mm
So not very thick. The spot you see on the neck is cosmetic shading not a functional flaw.

 

[MidOH]

Looks like it's just starting to patina there. Whole tank will look like that soon.

 

[Divin'Papaw]

Looks like it's just starting to patina there. Whole tank will look like that soon.

Bingo! Before too long the whole tank will be a hodgepodge of shades of silver/gray as it should be.

 

[OMyMyOHellYes]

"How far down does galvanizing go?"

I guess it goes as far down as you dive.

 

[runsongas]

galvanization is also considered "self healing" in that the surrounding zinc will function as a sacrificial anode for corrosion. it isn't like paint where any imperfections will lead to rust.

 

[Eric Sedletzky]

galvanization is also considered "self healing" in that the surrounding zinc will function as a sacrificial anode for corrosion. it isn't like paint where any imperfections will lead to rust.

And to add to that, with paint or powdercoating rust can (and will) creep under the coating and bubble the paint or PC and it will keep going causing pits and all sorts of nastiness. Paint was the worse idea ever for steel tanks.
With zinc and/or galvanizing it won’t do that. Rust will not start and creep between the zinc and steel interface. Amazing system really.