[PSA] Make sure to properly prepare your connections to aluminium terminal posts in order to ensure low contact resistance.

JoeHam

Photon Sorcerer
Joined
Dec 30, 2019
Messages
2,572

noenegdod

Solar Addict
Joined
Mar 21, 2020
Messages
626
So I see this:


And this:


IF I am following along correctly then the first choice will prevent oxidation AND reduce resistance while the second one will only prevent oxidation?

Should this be a measurable difference??

Honest question, just trying to learn something new today.

Until someone starts acting like an idiot I always assume everyone Im talking with is like me and just wants to learn ;)

Features & Benefits​

  • Resistivity of 23 Ω·cm
  • Improves electrical connections between irregular, pitted or corroded surfaces
  • Ensures electrical contact between loose or vibrating parts
  • Prevents arching, pitting, hotspots and welds
  • Inhibits corrosion
  • Fills gaps
  • Can be used on vertical surfaces
  • Silicone-free
I have emailed with MG chemicals tech support and they confirmed all my questions.

I have a little 25ml jar at home and using my cheap little ohm meter it measured 100 ohms from one side of the jar to the other side (about 1") The claim 1cm will test at 23 ohms

Ill take a picture tonight.
 

Just John

Photon Sorcerer
Joined
Aug 15, 2020
Messages
2,381
So I see this:


And this:


IF I am following along correctly then the first choice will prevent oxidation AND reduce resistance while the second one will only prevent oxidation?

Should this be a measurable difference??

Honest question, just trying to learn something new today.
I'm not sure that 23 ohms per square centimeter is actually a reduction in resistance. Personally I am much more concerned with preventing aluminum oxide formation, which introduces substantial resistance. Galvanic corrosion means that any corrosion occurring will occur preferentially on the aluminum.

They both make the same claims.

Ox-Gard Anti-Oxidant Compound contains prime grade zinc and is formulated with metallic zinc to create a compound that enhances electrical and thermal conductivity which is used on high power crimp connections and stud bolt mountings. When the connection is tightened, the grease is displaced, leaving a layer of zinc filling in the surface imperfections of the interface. This has a twofold effect; it improves electrical conductivity and it improves thermal conductivity. This reduces the connection temperature under high power conditions by a reduced voltage drop and by providing a heat conductivity path to the connection's substrate. Ox-Gard Anti-Oxidant Compound is manufactured with unique grease compounded from custom refined low sulphur oil. The grease base ensures brush-ability over a wide temperature range, tenacious adherence to all surfaces, resistance to water wash out and the prevention of rust and corrosion. This makes the product easier and more reliable to use.



  • Makes connections more reliable
  • Makes connections more weatherproof
  • Protects connections from corrosion
  • Reduces temperate rise
  • Low sulphur content
  • Non-reactive, no gassing in storage
  • Brushable over a wide temperature range
  • Sticks to wet joints

I'm not convinced that carbon is better than zinc. I know for preventing galvanic corrosion, zinc certainly has evidence to back up claims. They all basically exclude air to prevent corrosion, zinc is just added since it will corrode in preference to aluminum.
 
Last edited:

zzyzx

Apprentice Neanderthal
Joined
Aug 20, 2020
Messages
96
Sorry for throwing water on this cat fight, but I always like to read the 1-star and 2-star reviews of ANY Amazon product first as I like to know what people DON'T like about their purchase. The following 1-star and then 2-star review stated :

"This didn't work at all for me. I needed it to conduct electricity within a plug-in connection at the back of my car's lighting control module. It didn't work at all. I'm not sure why."

"Electric conductivity is not high enough for current flow at 0.5A."


Comments?
 

Just John

Photon Sorcerer
Joined
Aug 15, 2020
Messages
2,381
Sorry for throwing water on this cat fight, but I always like to read the 1-star and 2-star reviews of ANY Amazon product first as I like to know what people DON'T like about their purchase. The following 1-star and then 2-star review stated :

"This didn't work at all for me. I needed it to conduct electricity within a plug-in connection at the back of my car's lighting control module. It didn't work at all. I'm not sure why."

"Electric conductivity is not high enough for current flow at 0.5A."


Comments?
I don't know if that review is true, or subject to the "look at the source" rule. I do know that cheap resistors are made out of carbon, it's not a particularly good conductor. I also know that galvanic corrosion is a real thing, and zinc helps prevent it. Personally, I just want to prevent aluminum oxide, which is a very real problem and occurrence. Maybe not so much in the desert where I live now, but in any type of humidity, it is very real and I have personal experience with it. I'm just not convinced that identical claims represent any evidence for spending 6 times as much money on a product. Zinc on the other hand, has ample evidence (I haven't even mention galvanized nails until now).

 

Just John

Photon Sorcerer
Joined
Aug 15, 2020
Messages
2,381
Your apparently unaware of the fact that carbon is what the brushes in electric motors are made of.
I'm aware of the fact that brushes for my 1969 vw generator are made out of carbon for it's resistance to arcing (a byproduct of increased resistance). Not because they have lower conductivity.
 

Just John

Photon Sorcerer
Joined
Aug 15, 2020
Messages
2,381

noenegdod

Solar Addict
Joined
Mar 21, 2020
Messages
626
You don't really get the point. The objective is to exclude air and water and thus corrosion. Neither is a particularly good conductor as you demonstrate. Certainly I would not wish either infinite resistance nor 36 ohms resistance, I want metal to metal contact without corrosion.
One of us certainly is missing the point.

Last try.

In a perfect world, you would have absolutely flat, perfectly mating contact surfaces with no oxide or corrosion.

In the real world, no surfaces are absolutely flat therefor you have the possibility of both water and air entering the connection and oxidizing the surfaces and providing an electrolyte for corrosion. Both of these products prevent that.

Because of the non flat surface on both sides of the connection, there is only a relatively small area of high pressure contact area between the two sides of the connection, especially after someone has gone after the surfaces with a wire wheel on a dremel, sand paper with no rigid backing block or any other far from perfect world way of removing oxides from the surface. It is those voids that the corrosion inhibitor paste is needed to fill but it is also those voids filled with corrosion inhibitor which are non conductive, unless of course it is filled with a conductive corrosion inhibitor.

Filling these voids with a conductive material restores a portion of that lost conductivity, It is carbon, so its not as good as it would be if the surfaces were perfect, no-one ever attempted to claim that. What it is, is better than a non-conductive atmospheric exclude like noalox.

Yes the resistance is high from a conductor stand point. The probes are stuck in a jar and are about 1cm apart. The voids in the connection are a little shorter than that.
 
Last edited:

Hedges

I See Electromagnetic Fields!
Joined
Mar 28, 2020
Messages
8,396
It appears carbon serves as a cathode that accelerates corrosion of aluminum.
I don't find on MG's site any recommendations for or against use of their product with aluminum.
The paste contains carbon, but also grease to seal the connection.
I think we need environmental test results to indicate if it is compatible.


 

noenegdod

Solar Addict
Joined
Mar 21, 2020
Messages
626
It appears carbon serves as a cathode that accelerates corrosion of aluminum.
I don't find on MG's site any recommendations for or against use of their product with aluminum.
The paste contains carbon, but also grease to seal the connection.
I think we need environmental test results to indicate if it is compatible.



It does. I mentioned that above.

I have had 2 emails with their tech support and they confirmed to me that it was suitable for use with aluminum and as the grease excludes atmosphere from contact with the carbon, it is prevented from becoming a cathode.

I did not ask for environmental test results. I'll fire off an email to them tomorrow.
 

FilterGuy

What, me worry?
Joined
Nov 26, 2019
Messages
4,456
Location
Los Gatos CA
I should know better than to get in the middle of a cat fight..... but what the heck!!.

I think everyone would agree that No-lox is at least good enough. The question is whether the Carbon Conductive grease is better.

That has to be evaluated several ways.
  1. Which is lower cost.
    I don't think anyone is debating this, the Noalox is lower cost)
  2. Which provides the best protection from oxidation? (this must include long term protection...... can one dry out?)
    Since the reason for putting anything on the terminals is to prevent oxidation....if it does not do this then it is not an acceptable choice.
    I am willing to assume the Conductive grease is good enough..... so let's call this a draw.
  3. Are there bad side effects of either.
    Does it negatively interact with the aluminum? We don't know, but if it keeps out oxygen, it probably is not a problem.
    Does it create shorts? (conductive grease would if you are messy with it, but if you are careless there are lots of ways to create shorts)
    I am willing to call this a draw but it would be good to know if the galvanic corrosion can occur
  4. Which provides the best electrical connection?
    This is the big question. At first blush, I would think the conductive grease would be better. However.... there is a possibility it makes a worse connection. The way noalox works is that it is squeezed out an does not inhibit the faces of the lug and terminal from making a strong electrical connection. Does the carbon based grease adequately squeeze out? I don't know..... I think this is dependent on the size of the carbon dust that is used in the product. If a thin layer of carbon dust keeps the two surfaces from mating, it could actually create a much higher resistance connection. In the examples from the manufacturer it is all contacts that are sliding over each other so we can't safely assume a press connection would work well with the product.
    Without more data I have to call this an unknown.
After careful analysis, the answer is that I don't know which is better functionally. I would have to do some experiments to test the two and see if there is a detectable difference. (How is that for saying a lot of nothing? :))

So..... let me throw a bit more on the fire. If we are looking for conductive grease (and price is not an issue) lets go for a grease with Volume Resistivity of <0.01 ohm-cm
However, for the same reasons as the carbon grease, I don't know if it would be functionally better or not.
 
Last edited:

Gazoo

Dumb Dumb
Joined
May 12, 2020
Messages
2,794
Location
Texas
However, for the same reasons as the carbon grease, I don't know if it would be functionally better or not.
You beat me to it. I was getting ready to post this stuff.


I don't know if Chemtronics is better than MG Chemicals. But I would think either one is better than using carbon grease. Isn't silver the best conductor?
 

FilterGuy

What, me worry?
Joined
Nov 26, 2019
Messages
4,456
Location
Los Gatos CA
You beat me to it. I was getting ready to post this stuff.


I don't know if Chemtronics is better than MG Chemicals. But I would think either one is better than using carbon grease. Isn't silver the best conductor?
It is a reasonably good assumption that the silver grease is better than the carbon grease for making an electrical connection.....but since both of these are a grease with a dust mixed in.... I keep going back to the question of whether it can squeeze out enough.

The other thing to keep in mind is that Noalox is good enough and good enough is.... good enough.
 

mrdavvv

Solar Addict
Joined
Jan 14, 2020
Messages
380
I havent put any grease on my bats because i dont have enough info to make a decision!.. hope the fight brings something!
 

Hedges

I See Electromagnetic Fields!
Joined
Mar 28, 2020
Messages
8,396
I havent put any grease on my bats because i dont have enough info to make a decision!.. hope the fight brings something!

Bare aluminum?
Read the various threads, and you'll have enough info to put something on it.
 

Just John

Photon Sorcerer
Joined
Aug 15, 2020
Messages
2,381
You beat me to it. I was getting ready to post this stuff.


I don't know if Chemtronics is better than MG Chemicals. But I would think either one is better than using carbon grease. Isn't silver the best conductor?
I'm not sure where it rates, but silver plated copper is surprisingly cheap.
I think gold is maybe better. Depends on the application, gold plated connectors.

 

FilterGuy

What, me worry?
Joined
Nov 26, 2019
Messages
4,456
Location
Los Gatos CA
I'm not sure where it rates, but silver plated copper is surprisingly cheap.
I think gold is maybe better. Depends on the application, gold plated connectors.

If you use silver plated copper, be sure to also use a grease to seal it. Silver oxide is an insulator. Copper Oxide is not.
 

noenegdod

Solar Addict
Joined
Mar 21, 2020
Messages
626
I should know better than to get in the middle of a cat fight..... but what the heck!!.

I think everyone would agree that No-lox is at least good enough. The question is whether the Carbon Conductive grease is better.

That has to be evaluated several ways.
  1. Which is lower cost.
    I don't think anyone is debating this, the Noalox is lower cost)
  2. Which provides the best protection from oxidation? (this must include long term protection...... can one dry out?)
    Since the reason for putting anything on the terminals is to prevent oxidation....if it does not do this then it is not an acceptable choice.
    I am willing to assume the Conductive grease is good enough..... so let's call this a draw.
  3. Are there bad side effects of either.
    Does it negatively interact with the aluminum? We don't know, but if it keeps out oxygen, it probably is not a problem.
    Does it create shorts? (conductive grease would if you are messy with it, but if you are careless there are lots of ways to create shorts)
    I am willing to call this a draw but it would be good to know if the galvanic corrosion can occur
  4. Which provides the best electrical connection?
    This is the big question. At first blush, I would think the conductive grease would be better. However.... there is a possibility it makes a worse connection. The way noalox works is that it is squeezed out an does not inhibit the faces of the lug and terminal from making a strong electrical connection. Does the carbon based grease adequately squeeze out? I don't know..... I think this is dependent on the size of the carbon dust that is used in the product. If a thin layer of carbon dust keeps the two surfaces from mating, it could actually create a much higher resistance connection. In the examples from the manufacturer it is all contacts that are sliding over each other so we can't safely assume a press connection would work well with the product.
    Without more data I have to call this an unknown.
After careful analysis, the answer is that I don't know which is better functionally. I would have to do some experiments to test the two and see if there is a detectable difference. (How is that for saying a lot of nothing? :))

So..... let me throw a bit more on the fire. If we are looking for conductive grease (and price is not an issue) lets go for a grease with Volume Resistivity of <0.01 ohm-cm
However, for the same reasons as the carbon grease, I don't know if it would be functionally better or not.
You beat me to it. I was getting ready to post this stuff.


I don't know if Chemtronics is better than MG Chemicals. But I would think either one is better than using carbon grease. Isn't silver the best conductor?

YES!

In my opinion this is a huge win for everyone. I found silver epoxies and paints but hadnt stumbles across assembly paste and didnt think to search directly for it. I had searched in every way I could think of and only found carbon paste.

I would have used noalox if carbon paste wasnt an opton, Now what I know silver paste is a thing, Ill be using that!

FilterGuy, That was way more than a lot of nothing! Contemplative and reasonable discussion is an amazing skill. There are so few people in the world that are willing to let their thoughts out into the wild and just allow them to live or die. Most are just worried about being right. Personally, I dont care about being right, I just want to get to (what I believe) is a better place and you ( Gazoo was going to too) helped me and others do that. Thank you!

Edit: Just added it to the Digi-key cart. Not cheap at $60CAD but after spending over $6K on a batteries, inverter/charger and all the other miscellaneous pieces there isnt much point in cheaping out at this point :)
 
Last edited:
Top