On Tuesday, 27 February 2007 07:22:46 UTC, Brent wrote:
I have had a thought occur to me and i could use confirmation that I
am or i'm not nuts.

First off i live up in snow country and salt country, Ottawa Ontario
Canada

we put enough salt on our roads up here to make the ocean seem fit to
drink. And well Ottawa has one of the most aggressive snow removal and
salt plans going in in the first place.

So heres my question. has anyone or is there any reason not to
deliberately set up a galvanic cell by bolting an amount of magnesium
or zinc to the car body in a place where the elements can hit it? IF
i'm not "nucking futs" then the anode (Magnesium or zinc) getting wet
touching bare steel will set up a galvanic cell with the Mg being
sacrificed and "rusting/oxidizing" away to protect the steel of the
cars bodywork.

Am i nuts? is this doable? does anyone do this? Just curious?


If it matters drive a unibody car with an aluminum block (diesel jetta)

Hi, I have just removed the front stone guard and chassis end covers from my 1933 Rolls Royce for the first time since it was made and in the chassis cavity I find 3 magnesium sacrificial anodes each side. The chassis is steel and it's immaculate and the covers are aluminium and they are immaculate with no corrosion, the anodes however are almost completely corroded away.

Interestingly this car was first delivered to Ontario in 1933 for it's new owner Fredric William Cowan chairman of the Ontario Malleable Iron Company and it remained in the family's ownership until 1974 so the car knows about your environment and road conditions.

Seems the anode Idea is neither mad or new

On Tue, 12 Apr 2016 03:59:43 -0700 (PDT),
wrote:

On Tuesday, 27 February 2007 07:22:46 UTC, Brent wrote:
I have had a thought occur to me and i could use confirmation that I
am or i'm not nuts.

First off i live up in snow country and salt country, Ottawa Ontario
Canada

we put enough salt on our roads up here to make the ocean seem fit to
drink. And well Ottawa has one of the most aggressive snow removal and
salt plans going in in the first place.

So heres my question. has anyone or is there any reason not to
deliberately set up a galvanic cell by bolting an amount of magnesium
or zinc to the car body in a place where the elements can hit it? IF
i'm not "nucking futs" then the anode (Magnesium or zinc) getting wet
touching bare steel will set up a galvanic cell with the Mg being
sacrificed and "rusting/oxidizing" away to protect the steel of the
cars bodywork.

Am i nuts? is this doable? does anyone do this? Just curious?


If it matters drive a unibody car with an aluminum block (diesel jetta)

Hi, I have just removed the front stone guard and chassis end covers from my 1933 Rolls Royce for the first time since it was made and in the chassis cavity I find 3 magnesium sacrificial anodes each side. The chassis is steel and it's immaculate and the covers are aluminium and they are immaculate with no corrosion, the anodes however are almost completely corroded away.

Interestingly this car was first delivered to Ontario in 1933 for it's new owner Fredric William Cowan chairman of the Ontario Malleable Iron Company and it remained in the family's ownership until 1974 so the car knows about your environment and road conditions.

Seems the anode Idea is neither mad or new

Both metal hull boats/ships and buried pipelines use anodes so the
idea is certainly feasible although if one mixes various metals it
might be a bit complex to figure exactly what you wanted to do to
[protect all of them.

Another system that might be of interest is an electronic system, I
believe called a "Cathodic System" where sensors determine the
difference in potential and feed an electrical current to oppose
existing current flows.
--

Cheers,

John B.

On Tue, 12 Apr 2016 03:59:43 -0700 (PDT),
wrote:

On Tuesday, 27 February 2007 07:22:46 UTC, Brent wrote:
I have had a thought occur to me and i could use confirmation that I
am or i'm not nuts.

First off i live up in snow country and salt country, Ottawa Ontario
Canada

we put enough salt on our roads up here to make the ocean seem fit to
drink. And well Ottawa has one of the most aggressive snow removal and
salt plans going in in the first place.

So heres my question. has anyone or is there any reason not to
deliberately set up a galvanic cell by bolting an amount of magnesium
or zinc to the car body in a place where the elements can hit it? IF
i'm not "nucking futs" then the anode (Magnesium or zinc) getting wet
touching bare steel will set up a galvanic cell with the Mg being
sacrificed and "rusting/oxidizing" away to protect the steel of the
cars bodywork.

Am i nuts? is this doable? does anyone do this? Just curious?


If it matters drive a unibody car with an aluminum block (diesel jetta)

Hi, I have just removed the front stone guard and chassis end covers from my 1933 Rolls Royce for the first time since it was made and in the chassis cavity I find 3 magnesium sacrificial anodes each side. The chassis is steel and it's immaculate and the covers are aluminium and they are immaculate with no corrosion, the anodes however are almost completely corroded away.

Interestingly this car was first delivered to Ontario in 1933 for it's new owner Fredric William Cowan chairman of the Ontario Malleable Iron Company and it remained in the family's ownership until 1974 so the car knows about your environment and road conditions.

Seems the anode Idea is neither mad or new

Sacrificial anodes are widely used on boats -- magnesium for fresh
water and zinc for salt water. Aluminum (pure) is becoming more common
in salt water, and it's also more effective in brackish water.

Some things to keep in mind: It only works if you have a good
electrical connection between the anode and the metal being protected.
The water is not enough. You need either a good, clean contact, or an
electrical wire connecting the two.

Any of the steel that is not electrically connected will not be
protected. The way it works is that the anode/cathode (the cathode is
the steel, iron, aluminum alloy, brass or bronze) combination forms a
battery, and the anode material is "eaten" away as the "battery"
conducts electricity. The water is the electrolyte.

I have a couple of 10-pound anodes ("zincs") left over from when I
maintained my uncle's 42-foot boat. Two of them would last a year,
protecting the bronze prop shaft and the propeller, as well as the
stainless and bronze through-hull fittings. If the prop shaft was
stainless and if there was any aluminum down there, like an aluminum
propeller, they would have been eaten up in a few months without anode
protection.

I've never seen them installed on a car, but I suppose it would work.
You might look into the "pencil" zincs and magnesium rods that are
used in fresh-water cooling systems for salt-water boats.

--
Ed Huntress

On 4/12/2016 9:18 AM, Ed Huntress wrote:
....
The way it works is that the anode/cathode (the cathode is
the steel, iron, aluminum alloy, brass or bronze) combination forms a
battery, and the anode material is "eaten" away as the "battery"
conducts electricity. The water is the electrolyte.
...

Right! And where is the electrolyte in a car?

Bob

On Tue, 12 Apr 2016 09:50:23 -0400, Bob Engelhardt
wrote:

On 4/12/2016 9:18 AM, Ed Huntress wrote:
...
The way it works is that the anode/cathode (the cathode is
the steel, iron, aluminum alloy, brass or bronze) combination forms a
battery, and the anode material is "eaten" away as the "battery"
conducts electricity. The water is the electrolyte.
...

Right! And where is the electrolyte in a car?

Bob

I assume it's an intermittant thing: when the area is wet, you have an
electrolyte. When it's dry, you don't have to worry about corrosion,
anyway.

Again, I haven't seen it used on a car. I'm guessing about how it
would work in practice.

--
Ed Huntress

On 4/12/2016 10:26 AM, Ed Huntress wrote:

wrote:

On 4/12/2016 9:18 AM, Ed Huntress wrote:
...
The way it works is that the anode/cathode (the cathode is
the steel, iron, aluminum alloy, brass or bronze) combination forms a
battery, and the anode material is "eaten" away as the "battery"
conducts electricity. The water is the electrolyte.
...

Right! And where is the electrolyte in a car?



I assume it's an intermittant thing: when the area is wet, you have an
electrolyte. When it's dry, you don't have to worry about corrosion,
anyway.

Kinda' - when the _anode_ is wet you get protection, when it's dry and
anywhere else is wet, that anywhere else is not protected.

Again, I haven't seen it used on a car. I'm guessing about how it
would work in practice.

Me too - and my BS detector gave a low-level hum on the OP. The OP had
more details than the usual BS, but there is still the fundamental
chemistry issue. Maybe the Rolls in the OP had some kind of permanent
electrolyte that didn't need to be wetted. But then the anodes wouldn't
last 80+ years. I dunno.

Bob

On Tue, 12 Apr 2016 10:56:59 -0400, Bob Engelhardt
wrote:

On 4/12/2016 10:26 AM, Ed Huntress wrote:

wrote:

On 4/12/2016 9:18 AM, Ed Huntress wrote:
...
The way it works is that the anode/cathode (the cathode is
the steel, iron, aluminum alloy, brass or bronze) combination forms a
battery, and the anode material is "eaten" away as the "battery"
conducts electricity. The water is the electrolyte.
...

Right! And where is the electrolyte in a car?



I assume it's an intermittant thing: when the area is wet, you have an
electrolyte. When it's dry, you don't have to worry about corrosion,
anyway.

Kinda' - when the _anode_ is wet you get protection, when it's dry and
anywhere else is wet, that anywhere else is not protected.

Again, I haven't seen it used on a car. I'm guessing about how it
would work in practice.

Me too - and my BS detector gave a low-level hum on the OP. The OP had
more details than the usual BS, but there is still the fundamental
chemistry issue. Maybe the Rolls in the OP had some kind of permanent
electrolyte that didn't need to be wetted. But then the anodes wouldn't
last 80+ years. I dunno.

Bob

I think I'd have to see it. I can't picture it being very effective,
but then, Rolls Royce would go to extremes in the old days, to make
everything as perfect as they knew how. Maybe...

I wonder, too, about stray currents. Those are the really big problems
with boats, which are docked around electrical currents. The ground
rods for shore power -- often just an EMT shield -- tend to eat the
submerged metal parts of boats, even when they're protected with
sacrificial anodes. You probably have such stray currents in an old
car, which tend to have a lot of high-resistance paths to the battery
ground.

I'm skeptical but it's not something I've heard about before.

--
Ed Huntress

On Tue, 12 Apr 2016 19:13:43 +0700, John B.
wrote:

On Tue, 12 Apr 2016 03:59:43 -0700 (PDT),
wrote:

On Tuesday, 27 February 2007 07:22:46 UTC, Brent wrote:
I have had a thought occur to me and i could use confirmation that I
am or i'm not nuts.

First off i live up in snow country and salt country, Ottawa Ontario
Canada

we put enough salt on our roads up here to make the ocean seem fit to
drink. And well Ottawa has one of the most aggressive snow removal and
salt plans going in in the first place.

So heres my question. has anyone or is there any reason not to
deliberately set up a galvanic cell by bolting an amount of magnesium
or zinc to the car body in a place where the elements can hit it? IF
i'm not "nucking futs" then the anode (Magnesium or zinc) getting wet
touching bare steel will set up a galvanic cell with the Mg being
sacrificed and "rusting/oxidizing" away to protect the steel of the
cars bodywork.

Am i nuts? is this doable? does anyone do this? Just curious?


If it matters drive a unibody car with an aluminum block (diesel jetta)

Hi, I have just removed the front stone guard and chassis end covers from my 1933 Rolls Royce for the first time since it was made and in the chassis cavity I find 3 magnesium sacrificial anodes each side. The chassis is steel and it's immaculate and the covers are aluminium and they are immaculate with no corrosion, the anodes however are almost completely corroded away.

Interestingly this car was first delivered to Ontario in 1933 for it's new owner Fredric William Cowan chairman of the Ontario Malleable Iron Company and it remained in the family's ownership until 1974 so the car knows about your environment and road conditions.

Seems the anode Idea is neither mad or new

Both metal hull boats/ships and buried pipelines use anodes so the
idea is certainly feasible although if one mixes various metals it
might be a bit complex to figure exactly what you wanted to do to
[protect all of them.

Another system that might be of interest is an electronic system, I
believe called a "Cathodic System" where sensors determine the
difference in potential and feed an electrical current to oppose
existing current flows.
The electronic units are totally useless except for the insurance
policy that comes with them. Friends have 5 and 6 year old vehicles
that have had in excess of $5000 worth of rust repair done under
warranty. (make sure you keep up with the inspections or the policy is
null and void).

My daughter's Neon rusted very badly with the unit installed - no
warranty because one inspection had been missed. I have 20 year old
vehicle with no rust - used RustCheck.

I'm in tha salt and slush belt of Central Ontario - every bit as bad
for rust as Ottawa.

On Tue, 12 Apr 2016 09:18:09 -0400, Ed Huntress
wrote:

On Tue, 12 Apr 2016 03:59:43 -0700 (PDT),
wrote:

On Tuesday, 27 February 2007 07:22:46 UTC, Brent wrote:
I have had a thought occur to me and i could use confirmation that I
am or i'm not nuts.

First off i live up in snow country and salt country, Ottawa Ontario
Canada

we put enough salt on our roads up here to make the ocean seem fit to
drink. And well Ottawa has one of the most aggressive snow removal and
salt plans going in in the first place.

So heres my question. has anyone or is there any reason not to
deliberately set up a galvanic cell by bolting an amount of magnesium
or zinc to the car body in a place where the elements can hit it? IF
i'm not "nucking futs" then the anode (Magnesium or zinc) getting wet
touching bare steel will set up a galvanic cell with the Mg being
sacrificed and "rusting/oxidizing" away to protect the steel of the
cars bodywork.

Am i nuts? is this doable? does anyone do this? Just curious?


If it matters drive a unibody car with an aluminum block (diesel jetta)

Hi, I have just removed the front stone guard and chassis end covers from my 1933 Rolls Royce for the first time since it was made and in the chassis cavity I find 3 magnesium sacrificial anodes each side. The chassis is steel and it's immaculate and the covers are aluminium and they are immaculate with no corrosion, the anodes however are almost completely corroded away.

Interestingly this car was first delivered to Ontario in 1933 for it's new owner Fredric William Cowan chairman of the Ontario Malleable Iron Company and it remained in the family's ownership until 1974 so the car knows about your environment and road conditions.

Seems the anode Idea is neither mad or new

Sacrificial anodes are widely used on boats -- magnesium for fresh
water and zinc for salt water. Aluminum (pure) is becoming more common
in salt water, and it's also more effective in brackish water.

Some things to keep in mind: It only works if you have a good
electrical connection between the anode and the metal being protected.
The water is not enough. You need either a good, clean contact, or an
electrical wire connecting the two.

Any of the steel that is not electrically connected will not be
protected. The way it works is that the anode/cathode (the cathode is
the steel, iron, aluminum alloy, brass or bronze) combination forms a
battery, and the anode material is "eaten" away as the "battery"
conducts electricity. The water is the electrolyte.

I have a couple of 10-pound anodes ("zincs") left over from when I
maintained my uncle's 42-foot boat. Two of them would last a year,
protecting the bronze prop shaft and the propeller, as well as the
stainless and bronze through-hull fittings. If the prop shaft was
stainless and if there was any aluminum down there, like an aluminum
propeller, they would have been eaten up in a few months without anode
protection.

I've never seen them installed on a car, but I suppose it would work.
You might look into the "pencil" zincs and magnesium rods that are
used in fresh-water cooling systems for salt-water boats.
It'll work fine on your car if you park it in a full drainage ditch.
Doesn't (apparently) work too well dry.

On Tue, 12 Apr 2016 10:26:56 -0400, Ed Huntress
wrote:

On Tue, 12 Apr 2016 09:50:23 -0400, Bob Engelhardt
wrote:

On 4/12/2016 9:18 AM, Ed Huntress wrote:
...
The way it works is that the anode/cathode (the cathode is
the steel, iron, aluminum alloy, brass or bronze) combination forms a
battery, and the anode material is "eaten" away as the "battery"
conducts electricity. The water is the electrolyte.
...

Right! And where is the electrolyte in a car?

Bob

I assume it's an intermittant thing: when the area is wet, you have an
electrolyte. When it's dry, you don't have to worry about corrosion,
anyway.

Again, I haven't seen it used on a car. I'm guessing about how it
would work in practice.
The part that is going to rust can be wet and salty while the anode
location is clean and dry.

It's been tried - the results are not encouraging - not worth the cost
and effort of installing, generally speeking.

On Tue, 12 Apr 2016 12:02:38 -0400, wrote:

On Tue, 12 Apr 2016 09:18:09 -0400, Ed Huntress
wrote:

On Tue, 12 Apr 2016 03:59:43 -0700 (PDT),
wrote:

On Tuesday, 27 February 2007 07:22:46 UTC, Brent wrote:
I have had a thought occur to me and i could use confirmation that I
am or i'm not nuts.

First off i live up in snow country and salt country, Ottawa Ontario
Canada

we put enough salt on our roads up here to make the ocean seem fit to
drink. And well Ottawa has one of the most aggressive snow removal and
salt plans going in in the first place.

So heres my question. has anyone or is there any reason not to
deliberately set up a galvanic cell by bolting an amount of magnesium
or zinc to the car body in a place where the elements can hit it? IF
i'm not "nucking futs" then the anode (Magnesium or zinc) getting wet
touching bare steel will set up a galvanic cell with the Mg being
sacrificed and "rusting/oxidizing" away to protect the steel of the
cars bodywork.

Am i nuts? is this doable? does anyone do this? Just curious?


If it matters drive a unibody car with an aluminum block (diesel jetta)

Hi, I have just removed the front stone guard and chassis end covers from my 1933 Rolls Royce for the first time since it was made and in the chassis cavity I find 3 magnesium sacrificial anodes each side. The chassis is steel and it's immaculate and the covers are aluminium and they are immaculate with no corrosion, the anodes however are almost completely corroded away.

Interestingly this car was first delivered to Ontario in 1933 for it's new owner Fredric William Cowan chairman of the Ontario Malleable Iron Company and it remained in the family's ownership until 1974 so the car knows about your environment and road conditions.

Seems the anode Idea is neither mad or new

Sacrificial anodes are widely used on boats -- magnesium for fresh
water and zinc for salt water. Aluminum (pure) is becoming more common
in salt water, and it's also more effective in brackish water.

Some things to keep in mind: It only works if you have a good
electrical connection between the anode and the metal being protected.
The water is not enough. You need either a good, clean contact, or an
electrical wire connecting the two.

Any of the steel that is not electrically connected will not be
protected. The way it works is that the anode/cathode (the cathode is
the steel, iron, aluminum alloy, brass or bronze) combination forms a
battery, and the anode material is "eaten" away as the "battery"
conducts electricity. The water is the electrolyte.

I have a couple of 10-pound anodes ("zincs") left over from when I
maintained my uncle's 42-foot boat. Two of them would last a year,
protecting the bronze prop shaft and the propeller, as well as the
stainless and bronze through-hull fittings. If the prop shaft was
stainless and if there was any aluminum down there, like an aluminum
propeller, they would have been eaten up in a few months without anode
protection.

I've never seen them installed on a car, but I suppose it would work.
You might look into the "pencil" zincs and magnesium rods that are
used in fresh-water cooling systems for salt-water boats.
It'll work fine on your car if you park it in a full drainage ditch.
Doesn't (apparently) work too well dry.

Yeah, well, cars do get wet sometimes. And when I lived in Michigan,
the wet was salt water all winter long.

'Dunno. It's an interesting idea. But having worked on some large
boats, and having placed as many as six anodes on a hull to keep the
current paths through the water within protected range, I have a hard
time imagining how it would work on a car. But then, I haven't seen it
or done it.

--
Ed Huntress

On Tue, 12 Apr 2016 10:56:59 -0400, Bob Engelhardt
wrote:

On 4/12/2016 10:26 AM, Ed Huntress wrote:

wrote:

On 4/12/2016 9:18 AM, Ed Huntress wrote:
...
The way it works is that the anode/cathode (the cathode is
the steel, iron, aluminum alloy, brass or bronze) combination forms a
battery, and the anode material is "eaten" away as the "battery"
conducts electricity. The water is the electrolyte.
...

Right! And where is the electrolyte in a car?



I assume it's an intermittant thing: when the area is wet, you have an
electrolyte. When it's dry, you don't have to worry about corrosion,
anyway.

Kinda' - when the _anode_ is wet you get protection, when it's dry and
anywhere else is wet, that anywhere else is not protected.

Again, I haven't seen it used on a car. I'm guessing about how it
would work in practice.

Me too - and my BS detector gave a low-level hum on the OP. The OP had
more details than the usual BS, but there is still the fundamental
chemistry issue. Maybe the Rolls in the OP had some kind of permanent
electrolyte that didn't need to be wetted. But then the anodes wouldn't
last 80+ years. I dunno.

Bob

If you place different metals in contact with no electrolyte there is
no corrosion. If you place different metals in contact with an
electrolyte there is corrosion and if you add an anode the corrosion
takes place at the anode.

As has been mentioned they are commonly used on boats and outboard
engines and in sal****er cooled marine engines and even large
stationary power plants engines usually have anodes.
--

Cheers,

John B.

On Tue, 12 Apr 2016 12:00:39 -0400, wrote:

On Tue, 12 Apr 2016 19:13:43 +0700, John B.
wrote:

On Tue, 12 Apr 2016 03:59:43 -0700 (PDT),
wrote:

On Tuesday, 27 February 2007 07:22:46 UTC, Brent wrote:
I have had a thought occur to me and i could use confirmation that I
am or i'm not nuts.

First off i live up in snow country and salt country, Ottawa Ontario
Canada

we put enough salt on our roads up here to make the ocean seem fit to
drink. And well Ottawa has one of the most aggressive snow removal and
salt plans going in in the first place.

So heres my question. has anyone or is there any reason not to
deliberately set up a galvanic cell by bolting an amount of magnesium
or zinc to the car body in a place where the elements can hit it? IF
i'm not "nucking futs" then the anode (Magnesium or zinc) getting wet
touching bare steel will set up a galvanic cell with the Mg being
sacrificed and "rusting/oxidizing" away to protect the steel of the
cars bodywork.

Am i nuts? is this doable? does anyone do this? Just curious?


If it matters drive a unibody car with an aluminum block (diesel jetta)

Hi, I have just removed the front stone guard and chassis end covers from my 1933 Rolls Royce for the first time since it was made and in the chassis cavity I find 3 magnesium sacrificial anodes each side. The chassis is steel and it's immaculate and the covers are aluminium and they are immaculate with no corrosion, the anodes however are almost completely corroded away.

Interestingly this car was first delivered to Ontario in 1933 for it's new owner Fredric William Cowan chairman of the Ontario Malleable Iron Company and it remained in the family's ownership until 1974 so the car knows about your environment and road conditions.

Seems the anode Idea is neither mad or new

Both metal hull boats/ships and buried pipelines use anodes so the
idea is certainly feasible although if one mixes various metals it
might be a bit complex to figure exactly what you wanted to do to
[protect all of them.

Another system that might be of interest is an electronic system, I
believe called a "Cathodic System" where sensors determine the
difference in potential and feed an electrical current to oppose
existing current flows.
The electronic units are totally useless except for the insurance
policy that comes with them. Friends have 5 and 6 year old vehicles
that have had in excess of $5000 worth of rust repair done under
warranty. (make sure you keep up with the inspections or the policy is
null and void).

My daughter's Neon rusted very badly with the unit installed - no
warranty because one inspection had been missed. I have 20 year old
vehicle with no rust - used RustCheck.

I'm in tha salt and slush belt of Central Ontario - every bit as bad
for rust as Ottawa.

I have no idea of how effective the units for automobiles but I can
assure you that the similar systems used on buried pipelines are very
effective, certainly far more than anodes. I also understand, although
I've not seen it my self, that all very large shipping use the system.
--

Cheers,

John B.

On Tuesday, April 12, 2016 at 7:27:06 AM UTC-7, Ed Huntress wrote:
On Tue, 12 Apr 2016 09:50:23 -0400, Bob Engelhardt
wrote:

On 4/12/2016 9:18 AM, Ed Huntress wrote:
...
The way it works is that the anode/cathode (the cathode is
the steel, iron, aluminum alloy, brass or bronze) combination forms a
battery, and the anode material is "eaten" away as the "battery"
conducts electricity. The water is the electrolyte.

Right! And where is the electrolyte in a car?


Again, I haven't seen it used on a car. I'm guessing about how it
would work in practice.

It works fine; galvanized body was a feature of Americn Motors cars, at
least the 1964 Rambler I used to own.

It's not as cheap as good paint, though.

On Wed, 13 Apr 2016 00:28:02 -0700 (PDT), whit3rd
wrote:

On Tuesday, April 12, 2016 at 7:27:06 AM UTC-7, Ed Huntress wrote:
On Tue, 12 Apr 2016 09:50:23 -0400, Bob Engelhardt
wrote:

On 4/12/2016 9:18 AM, Ed Huntress wrote:
...
The way it works is that the anode/cathode (the cathode is
the steel, iron, aluminum alloy, brass or bronze) combination forms a
battery, and the anode material is "eaten" away as the "battery"
conducts electricity. The water is the electrolyte.

Right! And where is the electrolyte in a car?


Again, I haven't seen it used on a car. I'm guessing about how it
would work in practice.

It works fine; galvanized body was a feature of Americn Motors cars, at
least the 1964 Rambler I used to own.

It's not as cheap as good paint, though.

Well, galvanizing is a different story. Any spot that has to be
protected is immediately adjacent to zinc in that case.

--
Ed Huntress

On Wed, 13 Apr 2016 10:37:48 +0700, John B.
wrote:



I have no idea of how effective the units for automobiles but I can
assure you that the similar systems used on buried pipelines are very
effective, certainly far more than anodes. I also understand, although
I've not seen it my self, that all very large shipping use the system.
Well I have a real good idea how well they do NOT work from the 3
examples I provided. They were a pretty common "aftermarket upsell"
at many dealerships when I was in the business - and the dealer was
the only one who got any advantage out of the sale other than the rust
warranty (if it was vallidated by paying the dealer an annual
inspection fee) - and even then it seemed the vehicles with the units
installed needed a lot more rust repair than those that didn't -
particularly those that got an aftermarket oil / wax type rust spray.

On Tuesday, April 12, 2016 at 12:07:05 PM UTC-4, Ed Huntress wrote:




'Dunno. It's an interesting idea. But having worked on some large
boats, and having placed as many as six anodes on a hull to keep the
current paths through the water within protected range, I have a hard
time imagining how it would work on a car. But then, I haven't seen it
or done it.

--
Ed Huntress

I imagine you could get a bunch of magnesium fire starters like Harbor Freight sells and cut each one into three pieces , put a hole thru each piece and attach with self tapping screws. Then you could have one mounted close to every part of the car. But it would be a lot less work to paint places that need protection.

Dan

On Wed, 13 Apr 2016 11:56:49 -0700 (PDT), "
wrote:

On Tuesday, April 12, 2016 at 12:07:05 PM UTC-4, Ed Huntress wrote:




'Dunno. It's an interesting idea. But having worked on some large
boats, and having placed as many as six anodes on a hull to keep the
current paths through the water within protected range, I have a hard
time imagining how it would work on a car. But then, I haven't seen it
or done it.

--
Ed Huntress

I imagine you could get a bunch of magnesium fire starters like Harbor Freight sells and cut each one into three pieces , put a hole thru each piece and attach with self tapping screws. Then you could have one mounted close to every part of the car. But it would be a lot less work to paint places that need protection.

Dan

Having restored and repaired a few boat trailers that were regularly
dunked in salt water, the best thing I ever tried was a zinc-loaded
epoxy coating.

It was miserable to apply (very thick, and it drooled -- not
thixotropic at all), and very expensive, but it worked great. I
rotated the trailer 90 deg. after painting the top and bottom
horizontal surfaces, and then coated tops and bottoms of *those*
sides. You have to do that before the epoxy cures but after it starts
to gel, or the amine will blush and the overlap won't seal it. Then
wash off the amine with soap and water, rough it with steel wool, and
coat with a good boat enamel.

Second best was two coats of zinc chromate primer, and then two coats
of brush-on Rust-Oleum. That was the fish-oil based stuff that took a
week to dry hard.

--
Ed

On Wed, 13 Apr 2016 11:56:49 -0700 (PDT), "
wrote:

On Tuesday, April 12, 2016 at 12:07:05 PM UTC-4, Ed Huntress wrote:




'Dunno. It's an interesting idea. But having worked on some large
boats, and having placed as many as six anodes on a hull to keep the
current paths through the water within protected range, I have a hard
time imagining how it would work on a car. But then, I haven't seen it
or done it.

--
Ed Huntress

I imagine you could get a bunch of magnesium fire starters like Harbor Freight sells and cut each one into three pieces , put a hole thru each piece and attach with self tapping screws. Then you could have one mounted close to every part of the car. But it would be a lot less work to paint places that need protection.

Dan

Hear Hear!!