# hot dipped galvanized or stainless



## Wiresmith (Feb 9, 2013)

in a refinery outside, which is a better fastener material for attaching to galvanized columns, painted steel.

https://www.fastenal.com/en/70/corrosion

all corrosion charts i see point to hdg, but i know you have to consider the real world environment that it will be used in


i know stainless is the better fastener to attach to stainless

it will be used for attaching tinned or al/cu lugs, and before anyone says bronze check out the charts, i don't think bronze is the choice by what i have seen in old installations and seeing old broken bronze bolts just barely attaching a lug.


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## trentonmakes (Mar 21, 2017)

I would think stainless would be the better fastener. You could get by with the HDG, but if your asking which is better, I'd go with stainless

Texting and Driving


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## telsa (May 22, 2015)

Zinc will sacrifice itself for steel.

The real question is: "What are the vapors involved?"

Realistically, everything turns on that issue.


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## trentonmakes (Mar 21, 2017)

telsa said:


> Zinc will sacrifice itself for steel.
> 
> The real question is: "What are the vapors involved?"
> 
> Realistically, everything turns on that issue.


Yeah....they use zinc diodes on boat hulls to protect the metal.
You need to keep an eye on them and change em out once a certain percentage is gone.


Texting and Driving


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## Wiresmith (Feb 9, 2013)

telsa said:


> The real question is: "What are the vapors involved?"
> 
> Realistically, everything turns on that issue.


yep


a little sulfur, ammonia, water treatment chemicals (acids)

edit: all of these in there own little areas in the plant, not usually mixed and some areas have little exposure to anything


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## trentonmakes (Mar 21, 2017)

Wiresmith said:


> yep
> 
> 
> a little sulfur, ammonia, water treatment chemicals (acids)


When I was doing water treatment, I believe all the bolts and screws were stainless.
Granted most were small scale but we had some big ones servicing a whole building of a couple universitys.

Texting and Driving


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## Wiresmith (Feb 9, 2013)

trentonmakes said:


> When I was doing water treatment, I believe all the bolts and screws were stainless.
> Granted most were small scale but we had some big ones servicing a whole building of a couple universitys.
> 
> Texting and Driving


i should have specified that those chemicals aren't exposed to the entire facility but small parts within (sulfur one area, acid another(and yeah stainless here), and ammonia another)


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## gpop (May 14, 2018)

Doesn't a aluminum lug have a problem with stainless when exposed to moisture?


Ammonia doesn't like copper, and aluminum doesn't like acid. 


Maybe there isn't a one size fits all solution.


At least with zinc the tower will sacrifice its coating to protect the steel including your hardware.


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## minichopper6hp (Apr 19, 2014)

When we do water treat projects all the strut, fasteners, clamps etc are 316ss and all conduit is pvc coated aluminum rigid.

Sent from my Z981 using Tapatalk


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## Wiresmith (Feb 9, 2013)

gpop said:


> Maybe there isn't a one size fits all solution.


i believe there isn't and would like any suggestions from experience for the different locations


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## Wiresmith (Feb 9, 2013)

trentonmakes said:


> When I was doing water treatment, I believe all the bolts and screws were stainless.
> Granted most were small scale but we had some big ones servicing a whole building of a couple universitys.
> 
> Texting and Driving


what conduit did you use?


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## Wiresmith (Feb 9, 2013)

gpop said:


> Doesn't a aluminum lug have a problem with stainless when exposed to moisture?


normal aluminum does, although we use stainless hardware on aluminum tray.

but i think alcu lugs are a high grade aluminum and tin plated.

i didn't think of that though, thank you very much i will look into it more

http://ecat.burndy.com/Comergent/burndy/documentation/2010_mc_section_c-compression_connectors.pdf
"Aluminum compression connectors are manufactured
from high conductivity, high purity
wrought aluminum. They are designed with
sufficient mass and are electro-tin plated to
minimize corrosion due to galvanic action
between dissimilar metals. "


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## trentonmakes (Mar 21, 2017)

Wiresmith said:


> what conduit did you use?


If I remember right it was all stainless...604 maybe

Texting and Driving


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## MechanicalDVR (Dec 29, 2007)

Type 316 Stainless


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## Navyguy (Mar 15, 2010)

Wiresmith said:


> it will be used for attaching tinned or al/cu lugs



Use whatever material the lugs are made of. There is no value in getting a fastener that will "out live" the lug if it is going to be sacrificed during the next lug change.


Cheers


John


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## Wiresmith (Feb 9, 2013)

Navyguy said:


> Use whatever material the lugs are made of. There is no value in getting a fastener that will "out live" the lug if it is going to be sacrificed during the next lug change.
> 
> 
> Cheers
> ...


i haven't seen a burndy alcu tin plated lug rot, the base metal (usually galv steel or painted) actually corrodes though and rust is an insulator unless wet then just semiconductor, either way its part of the connection we're trying to make

what im kind of more asking about is the fastener and base material relationship


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## Navyguy (Mar 15, 2010)

What about using a paste like glyptal https://www.electro-wind.com/glypta...oating-130-c-red-aerosol-spray-can-361-g.html


or


never seize http://bostik-industrial.com/never-...r-using-anti-seize-and-lubricating-compounds/


Cheers
John


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## Southeast Power (Jan 18, 2009)

Navyguy said:


> What about using a paste like glyptal https://www.electro-wind.com/glypta...oating-130-c-red-aerosol-spray-can-361-g.html
> 
> 
> or
> ...


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## Wiresmith (Feb 9, 2013)

Navyguy said:


> What about using a paste like glyptal https://www.electro-wind.com/glypta...oating-130-c-red-aerosol-spray-can-361-g.html
> 
> 
> or
> ...


thanks

i agree using supplements like those greatly improve the lifespan.

deciding the correct fastener material is my first step though, in high corrosion areas i am going to try to push to have this used

how well do you have to prepare the surfaces for glyptal to adhere well(and for a long time), this is real world construction out in the field and in existing facility (i will read its instructions but im asking about real world experience)

instead of never sieze i would use penetrox because its an electrical application, you can get cans with brushes of it


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## Navyguy (Mar 15, 2010)

I have only used Glyptal for grounding and lightening connections below ground. Some of those connections are no over 20 years old. They were protected in "inspection cans", so that has aided in their lifespan. I have no idea on the direct burial connections I have done... I generally don't go digging them up to check!


As far as never-seize goes, I would put it on after the connection was made. Agreed that it is not a "permanent solution", but I used this extensively in food plants where it was subject to harsh chemicals, washdown, etc and it protected the fasteners and the connection. We use SS fasteners, but only because that is what we stocked, not because we felt it was any better.


In most cases, when we had to remove a connection, the bolt was simply snapped off and replaced any way, so in some respects it did not really matter what we used. In food, rust is a no-go, so despite trying to protect with never-seize if there was rust (and stainless does rust), it had to be replaced anyway.


In your case, perhaps a simple coating of gear lub or some other grease that would hold up to the weather and chemicals might be the better option then never-seize; this would encapsulate the connection and you should be good to go.


Cheers


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## Wiresmith (Feb 9, 2013)

Navyguy said:


> I have only used Glyptal for grounding and lightening connections below ground. Some of those connections are no over 20 years old. They were protected in "inspection cans", so that has aided in their lifespan. I have no idea on the direct burial connections I have done... I generally don't go digging them up to check!
> 
> 
> As far as never-seize goes, I would put it on after the connection was made. Agreed that it is not a "permanent solution", but I used this extensively in food plants where it was subject to harsh chemicals, washdown, etc and it protected the fasteners and the connection. We use SS fasteners, but only because that is what we stocked, not because we felt it was any better.
> ...


thanks for the info

you probably already know this, but just in case. if you put some grease on your stainless threads they won't gall and seize. stainless fasteners gall real easy especially if you tighten them with an impact (the heat from tightening with impact increases galling) 

also if you use a grease that doesn't increase surface resistance(why i stated using penetrox) in the connection it can seal out oxygen and liquids and reduce corrosion and galvanic reaction, but just coating after connection also greatly helps

https://objects.eanixter.com/PD3728...c=232709184.1.1528047462628&__hsfp=1607898099


stl8 in some applications

https://www.galco.com/techdoc/cohi/stl8_cp.pdf


in my experience copper based greases work well but when i see normal galvanic charts it makes me think to keep copper away from steel

thanks again, i value real world experience a little more than product information from manufacturers and its harder to come by


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## Jlarson (Jun 28, 2009)

Typical spec for us when attaching to galvanized structure outside is stainless steel hardware, nickle anti seize, plated hypress lugs w/ heat shrink then the area is sprayed with cold galv after since we take the galvy off under the lug.


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## Wiresmith (Feb 9, 2013)

Jlarson said:


> Typical spec for us when attaching to galvanized structure outside is stainless steel hardware, nickle anti seize, plated hypress lugs w/ heat shrink then the area is sprayed with cold galv after since we take the galvy off under the lug.


whats your opinion on taking the galv off? do they require you chase your conduit threads and assemble them unpainted?


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