Galvanising machined components

[eski1]

Hi
I have a few small mild steel machined components which I need to get galvanised as the customer has requested it . They are going under water in a sewage treatment works so i assume this is the best treatment .
My question is some of the parts have threads and bore diameters which i wouldnt want coating . Is there a way of putting something on them so the galvanise dosen't stick etc .
I thought about screwing bolts into the threads & fitting shafts in the bores and removing afterwards , but wasn't sure how easy they would be to remove and if the galvanise might chip when taking them out etc .
Any suggestions welcome

Cheers
chris

 

[jbeckhou]

Have you thought about using a different coating such as QPQ or Phosphate?

Not sure about how to prevent the galvanize process from bonding to the threads. What does your vendor recommend?



Petrotrim Services

 

[btrueblood]

Not sure I would trust galvanized steel to last very long submerged in sewage.

 

[CoryPad]

http://www.galvanizeit.org/aga/designing-fabricating/design-considerations/masking

 

[blacksmith37]

Hot dip or electro galvanize ? Not my area, but I thought "stop" coating to protect some areas was standard procedure. Also, some application accept "zinc rich" primer coating as "galvanizing. I agree that it doesn't sound like good protection for sewage.