Brass - Electrical Flow - Technical info Request

[Richstag]

Hi,

Here you can see how I maintain my mech as far as contacts (tube ends, threads, pins, switches).

I do have a technical question for any electrical gurus in the know on this forum.

I read that the electrical current flows on the outside of the mech tube. A mod maker mentioned this and was alluding to the fact that a patina on the outside of a brass/copper mod may or may not hinder electrical flow.

So, my question is if the current does flow on the outer wall, is the actual outside where it will flow or the inner wall of the tube? Also, how much impact does a patina on the outside actually effect the electrical flow of the circuit?

I am looking for a technical answer and explanation for this if anyone knows.

Thanks,

[Earthling789]

Electricity 101... Electrons flow in the path of least resistance, just like water.

Just like a Mag-light flashlight, the negative side of the battery contact makes the contact at the base of the tube, and conducts the electron flow along the tube... not the painted outside, not the coated inside, the whole tube. Patina, just like paint on the outside of a Mag-light, does not affect the flow of electrons in the least. The flow is (and will be) directed along the path of least resistance, which will utilize the entire tube, just like house-current utilizes the WHOLE wire.

Patina is on the exterior surface of the tube only, and even heavy patina is only hundreds of thousandths of an inch thick (which is why it can be cleaned off so easily). It does not penetrate through the whole wall, like rust, and does not have any significant impact to electron flow.

Clean contact points are FAR more important to good power flow.

EDIT:

I guess I should also point out that Brass is technically a Copper/Zinc alloy, and sometimes has other metals to make it more resistant to extreme weather (naval brass), etc. Copper is extremely conductive, Zinc... well, it does conduct electricity, it's not nearly as good as Copper or Aluminum... Most of the Brass MODs are 60/40 or 70/30 mixes, and the really reddish colored ones could be as high as 80/20. The more Copper content, the better they are at conducting electricity; however, even with a 50/50 content, there is more than enough Copper to "spider-web" conductivity of electricity from one end to the other. Highly desired Brass, which will not patina as quickly, and will hold up to the "elements" better than most are Naval Brass or Admiral Brass... which contain 1-2% Aluminum or Tin (respectively), which makes them far better for use around salt-water, and thus hold up well to the oils and salts in your hands. Brasses that patina faster (more greenish blue colored patina) have higher Copper content. Most of the patina I've seen in MODs are likely 60/40 mixes or 59/40/1 (with added tin or Aluminum), and have a very pretty dark-blue-to-grey patina.

Edited June 22, 2014 by Earthling789

[Richstag]

I hear, you and thanks for your thoughts.

This was a comment made by a well thought of high end mech mod builder.

I realize the path of least resistance, but another topic was how DC current flows differently. I also get patina usually doesn't eat into the steel, though it certainly can.

This is probably a very technical question that is going to be requiring a subtle and technical answer IMHO.

I get what you are saying about hard anodized lights and such, but perhaps the current flows directly under that current through the, usually, aluminum body?

Also, I have the contacts under control, so this is trying to figure out the last link in the series.

Thanks again for your time and thoughts.

[Richstag]

Well, consider my input as a Mod Maker/manufacturer:

Hard hitting would depend on the build. If a mod has a higher voltage drop, then a lower ohm coil can produce "hard hitting" results. Same specs and tolerances on my mods, just different materials Copper, Brass, and Stainless Steel. There wasn't more than a .02v drop difference between the materials. In fact the Brass was producing the same Voltage Drop as the Copper. We will be testing with @jkuro soon to have what's become a standardized test performed.

There are some Copper mods out there and people do have them in their hands. Check out ToddsReviews and The Hill Giant review on YouTube.

The patina will depend on the grade of copper used. The best is Oxygen Free Copper. Patina comes slowly. Starts in a day and takes a week or so to build a slight patina. If one likes a strong Patina, then there are chemicals out there to bring in on quicker. May degrade performance though as electrons move on the outside of a material.

No Metalic smell using the Oxygen Free copper. My Brass ones don't smell either. Maybe it's the grade of materials that is creating the odor. Also, the Oxygen Free copper does not turn green.

Like I said originally, the hit can be altered by the coil build. My Brass SurfRider is hitting really well on a 1.1 ohm build. I vape at 12mg. With other mods the Throat hit went away, but because of our design, it has come back. Ima liking it!!!

At the end of the day, vape what you like. Could be a Coppermod or am XXIX. The best vape is the one that's right for you. Check out the XXIX and SurfRider thread going on here. You'll get more info.

I hope this was helpful.

Here is a snip of the discussion just in case I am relaying wrong. I am looking to understand this relationship.

[Richstag]

Electricity 101... Electrons flow in the path of least resistance, just like water.

Just like a Mag-light flashlight, the negative side of the battery contact makes the contact at the base of the tube, and conducts the electron flow along the tube... not the painted outside, not the coated inside, the whole tube. Patina, just like paint on the outside of a Mag-light, does not affect the flow of electrons in the least. The flow is (and will be) directed along the path of least resistance, which will utilize the entire tube, just like house-current utilizes the WHOLE wire.

Patina is on the exterior surface of the tube only, and even heavy patina is only hundreds of thousandths of an inch thick (which is why it can be cleaned off so easily). It does not penetrate through the whole wall, like rust, and does not have any significant impact to electron flow.

Clean contact points are FAR more important to good power flow.

EDIT:

I guess I should also point out that Brass is technically a Copper/Zinc alloy, and sometimes has other metals to make it more resistant to extreme weather (naval brass), etc. Copper is extremely conductive, Zinc... well, it does conduct electricity, it's not nearly as good as Copper or Aluminum... Most of the Brass MODs are 60/40 or 70/30 mixes, and the really reddish colored ones could be as high as 80/20. The more Copper content, the better they are at conducting electricity; however, even with a 50/50 content, there is more than enough Copper to "spider-web" conductivity of electricity from one end to the other. Highly desired Brass, which will not patina as quickly, and will hold up to the "elements" better than most are Naval Brass or Admiral Brass... which contain 1-2% Aluminum or Tin (respectively), which makes them far better for use around salt-water, and thus hold up well to the oils and salts in your hands. Brasses that patina faster (more greenish blue colored patina) have higher Copper content. Most of the patina I've seen in MODs are likely 60/40 mixes or 59/40/1 (with added tin or Aluminum), and have a very pretty dark-blue-to-grey patina.

Thanks again, and I get the different compositions of varying brass alloy. Please see the quoted snip and let me know what you think.

[Earthling789]

DC current flows from Negative to Positive, along the path of least resistance... yes, electrons will flow along the outer edge of the metal, but not ONLY along the outer edge... and even if this were true, there are TWO, distinct outer surfaces... the one you touch, and the inner-wall.

Patina will not conduct electricity, as it is oxidation... think of it as insulation on a wire, which does not prevent a wire from conducting electricity, it actually increases it's load capacity.

When looking at the thickness of your MODs wall, think of all the molecules of Copper that are contained within that width... Electricity will flow from molecule to molecule, across the entire thickness of the wall, not just the molecules along the outer surfaces.

Bottom-line, his statement that electricity is ONLY flowing along the outer edge of the MOD is incorrect.... otherwise, power wires would be thin-walled tubes, rather than solid-core or stranded wires, because there is far more surface-area in a tube than a solid strand, and per cubic-inch, solid and stranded wire conducts the same. Since solid-core and stranded wires of the same gauge conduct the same, clearly the "surface only" flow concept is already incorrect, as there is a lot more surface area in stranded wire cables than the same gauge of solid-core! We only see more stranded wire cables because they are more flexible and less subject to breakage than solid-core cables.

[Richstag]

Thank you for such a good depiction. What if the path of least resistance is the Outter surface? I keep the inner walls spotless but I was just curious about his statement. Also, the Outter wall vs the inner wall vs the threading and tube ends. The path.

[Richstag]

Oh, and from my testing of power generation equipment days, they wouldn't use hollow cables because the higher power the larger gauge the cables have to be. That's why I was thinking this may be more subtle. I'm sure we are running low power for the thickness of my mechs walls. There is a general guide for cable size to power.

[Earthling789]

Thank you for such a good depiction. What if the path of least resistance is the Outter surface? I keep the inner walls spotless but I was just curious about his statement. Also, the Outter wall vs the inner wall vs the threading and tube ends. The path.

Well, due to what is called "skin-effect", electrons do move faster along the outer skin of a conductor, but that movement is not restricted to only the outside edge, and patina will not stop that flow, as it is essentially an insulator. Think of any conductor (wire, strip, plate, etc.) as a water-hose, and the water is electricity... water uses the whole hose to move, just like electricity uses the whole wire, but even water moves faster along the outer edge of a column, due to resistance created inside the column... electricity is very similar.

I think what he is referring to is "skin-effect", but this has far more to do with signal degradation of frequencies, such as audio and video, and occurs over GREAT distances (hundreds of feet, or even miles) to degrade high-frequencies. This is not an issue when we're talking about 6-inches of MOD length, and not when your talking about movement of electrons from negative to positive along/through the body of the MOD's (primarily) Copper tube, where frequency is not a factor.

I've seen solid Copper cable, non-insulated, completely covered in thick, green oxidation, still conducting power just like it did when it was new...

Edited June 22, 2014 by Earthling789

[Richstag]

I would think other reasons not to use hollow wire would be cost, durability, flexibility and more. What I am thinking is we are pushing so little power that most can run through the Outter wall for the least resistance. This skin effect sounds like it could be restricted by a layer of oxidation. I think there may be something to this, just not enough to effect daily vape. Thanks for thinking this one through with me.

[Earthling789]

Yeah, you nailed it for hollow cables... they're just not "practical" for everyday use. But rest-assured that a little patina on your MOD will not adversely affect it's performance, because beneath that patina is still unencumbered Copper, capable of conducting electricity! Yes, oxidation over miles may reduce the ability to conduct by tenths of a percent, but still, we're talking about a few inches in length, more than an inch in diameter, and 3-4" in circumference?? (That's a lot of area) And, if patina were a real problem, painted or coated MODs would have even more issue, right?

Like I said earlier, your biggest point of failure will be your contact-points... patina is negligible, and the weathered-look should be enjoyed, at least I enjoy the look of good patina on Brass and Copper

[Richstag]

Yeah, that's good cuz I love patina and somewhat hate Shiney brass for a daily carry. Yeah, painted, coated, hard anodized would not have the "skin effect" right? And a layer of oxidation would become the surface so the skin effect would have to move to the inner wall? Thus causing a longer path? I know this may seem ridiculous but the more I understand the better I feel. I am an OCD German. I can't help it.

[Earthling789]

Well, skin-effect has more to do with frequency degradation over distance, and less to do with an actual "skin" or coating.

The patina (or paint or other coating) add resistance, just like any insulator on a wire, but that resistance is negligible for what we're talking about (again, short distance and large area). Patina, or any insulator may cover the upper surface, but always remember, directly below that layer is "clean" Copper, which now becomes the "outer" layer, whether it be outside where you touch, or inside next to the battery. Patina is oxidation which forms over the outer layer and is microns in thickness... and is always there, even after you clean it... and the build-up of it, to where it is visible does not fundamentally change the outer-layer (or internal) conductivity of the Brass/Copper.

So, yes, enjoy the beautiful patina!

[Conneazoo]

Dang you two. Cool discussion.

Thanks for the good read!

[Richstag]

Going to enjoy the patina Just went to my local shop and got in on a custom aluminum 120w box mod build. Getting mine media blasted. Should be killer. Tried the prototype out. Awesome.