How much anti-oxide to use?

Seahawk

Member
Yes, this is yet another thread on AL anti-oxide use. BUT I've read all the many threads I could find on here and did not find any reference to how much of the stuff to apply. The reason I ask is that I did a AL meter install w/ 4/0 Alcan Stabiloy for which I put on about ... oh... 1/2 as much as I'd put toothpaste on a toothbrush and then worked it in with a wire brush... and then put a thin layer within the terminal.

The inspector passed me but wants me to "squirt in" a bunch of it atop the connection to block out the air. I don't see any reference leading to such an application being appropriate.

So I guess bottom line: how much to use on 4/0 wire and/or what should it look like when done? Should I be setting the wire into a big old glump of it within the terminal?

(Btw, I went back and looked at the brush I'd used and realized its brass, not steel... any thoughts as to the effectiveness or ineffectiveness of such a brush)
 

iwire

Moderator
Staff member
The NEC does not require the use of anti-oxidant paste, you could tell the inspector to pound sand or just squirt some goop on and make him happy.
 

don_resqcapt19

Moderator
Staff member
As far as I know we only need to prevent the formation the non-conductive aluminum oxide at the actual point of connection. That is where the conductor is in physical contact with the connector. It really doesn't matter if aluminum oxide forms on the bare conductor that is not in contact with the connector.

What does the instructions for the anti-oxide compounds tell you to do? I have never seen any that say to fill the top of the connector to keep air out.
 

augie47

Moderator
Staff member
"keep the air out".,,, humm.... wonder if he will accept antioxident as pool
potting compound or maybe seal-off compound. :grin:
 

infinity

Moderator
Staff member
The NEC does not require the use of anti-oxidant paste, you could tell the inspector to pound sand or just squirt some goop on and make him happy.
:grin::grin::grin:


It's frustrating to hear this so often that I wish that someone would please send out a memo to all inspectors and tell them that this stuff is not even required. :roll:
 

Hendrix

Senior Member
:grin::grin::grin:


It's frustrating to hear this so often that I wish that someone would please send out a memo to all inspectors and tell them that this stuff is not even required. :roll:
I think that most of us know that.:roll:
 

pete m.

Senior Member
Most instructions that I have seen for de-ox require that it be "brushed" into the conductor and the terminal.

If it were required (by possibly a job spec) I still have yet to see it be applied as stated in the manufacturers instructions. 10 times out of 10 the end of the conductor is just dipped in the bottle or the stuff is just smeared everywhere that there is bare aluminum.

Pete
 

rcarroll

Senior Member
As stated above, not required by code. I did check w/ a wire mfg. & an anti oxidant was recommended, not mandatory.
 

K8MHZ

Senior Member
Most instructions that I have seen for de-ox require that it be "brushed" into the conductor and the terminal.

If it were required (by possibly a job spec) I still have yet to see it be applied as stated in the manufacturers instructions. 10 times out of 10 the end of the conductor is just dipped in the bottle or the stuff is just smeared everywhere that there is bare aluminum.

Pete
Not 10 out of 10. I brush it in just like the instructions call for. Having spent years in industrial maintenance I can tell you with no uncertainty that the stuff works. Of course you are right that the majority just puts it on without working it in with a brush, even so it's good stuff. Applying it properly will insure a pristine connection for a century or so.
 

don_resqcapt19

Moderator
Staff member
Isn't the newer AL made of a different alloy or compound that doesn't need the paste?
No, that changed the thermal expansion properties of the conductor but not the fact that aluminum oxidizes and the fact that alumimum oxide is an insulator. It forms almost instantally when bare alumimum is exposed to air and that is the reason that the instructions say to wire brush it on to the conductor. As the wire brush removes the oxide, the oxide inhibitor covers the bare metal and prevents new oxide from forming.

One reason that not all instructions say to use an inhibitor is the fact that aluminum oxide is very brittle and will shatter with the pressure of making the connection. The pressure of the connection excludes air from the actual points of contact and new oxide cannot form.
 

pete m.

Senior Member
Not 10 out of 10. I brush it in just like the instructions call for. Having spent years in industrial maintenance I can tell you with no uncertainty that the stuff works. Of course you are right that the majority just puts it on without working it in with a brush, even so it's good stuff. Applying it properly will insure a pristine connection for a century or so.
The 10 out of 10 was a little near-sighted... I was referring to the installations that I have witnessed. Sorry about that.

Pete
 

K8MHZ

Senior Member
No, that changed the thermal expansion properties of the conductor but not the fact that aluminum oxidizes and the fact that alumimum oxide is an insulator. It forms almost instantally when bare alumimum is exposed to air and that is the reason that the instructions say to wire brush it on to the conductor. As the wire brush removes the oxide, the oxide inhibitor covers the bare metal and prevents new oxide from forming.
Correct.

If you have ever successfully soldered aluminum you would have had to wire brush the flux in to get a good flow. That's the trick and why conventional soldering techniques don't work with aluminum.

I have made solder stick to steel by exposing the bare metal while keeping the surface covered with flux. Care must be taken to not let any part of the metal touch air while the solder is being applied.

That tells me that steel also oxides instantly. We all know that it oxides completely over time as well, so why not be putting oxide inhibitors on steel as well?
 

Seahawk

Member
Well I'm glad to hear I'm not nuts for thinking the inspector was. :)

I do want to arrive at a concensus on the amount of goo to use though... I think I'm ok on the conductor side... but the terminal I usually just put a thin film on ... do y'all put more of a creamy layer on? (I think we agree no need for pudding!)

Also, I read on one of the threads to use a steel brush... as I said I used brass... I was thinking brass would not scratch/etch the conductor... but maybe that is the point of it? Am I ok w/ brass or should I redo w/ steel and/or use steel going forward?

I'm new to the forum and already you guys are proving invaluable.

Thanks!
 

don_resqcapt19

Moderator
Staff member
...
That tells me that steel also oxides instantly. We all know that it oxides completely over time as well, so why not be putting oxide inhibitors on steel as well?
Probably because iron oxide, like copper oxide is a conductor and does not cause the same problem as the non-conducting aluminum oxide.
But we do use oxide inhibitors all the time on steel to protect it...paint and other coatings such as zinc.
 

iwire

Moderator
Staff member
Having spent years in industrial maintenance I can tell you with no uncertainty that the stuff works.
I don't think that you can tell us that unless you had made the same number of connections in the same environments without using the paste.
 

K8MHZ

Senior Member
I don't think that you can tell us that unless you had made the same number of connections in the same environments without using the paste.
It doesn't matter who made them. I have seen both in pretty much the same environment and those that weren't protected were always in worse shape than those that were.
 

K8MHZ

Senior Member
Probably because iron oxide, like copper oxide is a conductor and does not cause the same problem as the non-conducting aluminum oxide.
But we do use oxide inhibitors all the time on steel to protect it...paint and other coatings such as zinc.
Good answer as far as an electrician is concerned.

I also dabble in other trades and strongly rely on Permatex Never Seize. It prevents seizing by filling in the voids between threads and keeping all moisture out. Great stuff. It also has powdered metal in it so the threads don't actually touch each other. Don't tell anyone, but I have used it on electrical connections. In fact, the stuff with the powdered copper in it just BEGS to be used on electrical connections.
 
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