Mounting radiators - electrolysis(?) concerns

[Pube]

Im concerned with the effects of electricity when mounting my water to air intercooler heat exchanger. The unit is a PWR item and has mounting brackets that suit the heat exchanger to be rigid mounted to the body of the car as opposed to many factory radiators that have pins on the upper and lower tanks that can be mounted on rubber grommets. A mate of myne had an alloy engine radiator that failed (leaked) within a couple of months due to an electrical current passing through the radiator as the raidator was not rubber mounted. Will this happen to my heat exchanger if it is not rubber mounted??

[oldcorollas]

are your earth straps from the engine up to scratch?
what is the voltage difference between the body of the radiator and the engine block?

acidic coolant might be more of a concern than "stray current"

[Bobomacho]

electrolysis is where the current is running through the coolant? to my understanding the current breaks down the anti-corrosion properties of it and fucks all sorts of shit up at an accelerated rate!

[Pube]

To be honest, im not entirely on the ball in this area. How does electrolysis destroy a radiator? Is it when your engine coolant has some current flow in it and therefore earths through the raditator onto the body?

[IN 05 NT]

electrolysis eats away at alloy, metal, kinda like coke bubbling inside you mouth....

im not to hot on this topic either.....

[Norbie]

As oldcorollas hinted, "stray current" is a symptom of poor earthing. Basically if your body-to-engine earth cable(s) are not up to scratch some of the current will pass via the coolant (which can conduct a small amount of electricity) and this creates an electrochemical reaction which corrodes metal at an accelerated rate.

In short, make sure your earth cables are in good shape and everything will be fine.

[30psi 4agte]

NORBIE is spot on.

Make sure you have decent earths from engine to body. You may need to add extra.

You can test for electrolysis by using a multimeter on the volts setting.
Place one end of meter to earth and the other in the water of you radiator or IC in your case making sure that the lead is touching nothing but the coolant /water.

This will test for any electrical current in the system.

If you dont have a multimeter ( they are like $20 from dicks) go to a workshop and they should beable to test it there and then for ya.

[Pube]

cool, thanks for the info fellas!

[river]

Hi,

I suppose you could fill your cooling system with mercury, and that way it will be able to reath itself out also.

seeyuzz
river

[Ribfeast]

Make sure the radiator is electronically isolated from the rest of the car. Since the radiator is made from a different metal to the car's body, you will get an electrolysis effect if it touches the bodywork.
I think the Toyota red coolant has some stuff in it to slow this effect down also.

[sideshow]

my alloy rad is bolted direct to chassis and still i got electrolysis

i made 10 mm earths 3 on enigne and 2 on radiator still didnt fix prob

u can have 50 earths on it but still it can fail

here is how to test it

get multimeter select 2 or 20 volts range

put black lead on bat neg or rad body

put red lead in radiator cap touching the coolant but not touching the radiator it has to onlyyyyyy touch coolant

i was gettin 0.5 volts when car was hot

here is how to cure it

goto woolies get afew bottles of demineralised water

drain water system completely

fill with only deminaralised water

run engine and get hot retest voltage

mine dropped to .10 after this

then once its all ok with plain demineralised water then add yr coolant

u need to check it before u add coolant incase yr coolant has faults

once u add coolant then get hot and recheck

this can happen when u have alloy engine and alloy rad

and extra earths will not fix it all the time that is a myth

proper radiator shops have a veryyyy sensitive meter for checking electrolysis

so my problem was not bad earth it was the impurities in tap water that when it reach a hot temp circulating thru enigne cause an actual voltage


another thing is like ribfeast said use quality coolant

some taiwanese coolant might cause more headaches

when u spend up to 1000 for a good alloy radiator whats afew more on keeping it from eating itself

ive had to use araldite in a spot to stop leaks

[Pube]

thanks fo that sideshow, I forgot about impurtities in tap water. I will carry out the test with the multimeter to check the amount of current flow. What about those pre-mix coolant containers, do they use demineralised water?

[sideshow]

just get concentrate mix i got red toyota stuff from autobarn
then ill mix it with deminaralised water same water they recomend for clothes irons so they dont rust or corrode

[oldcorollas]

here is how to cure it

goto woolies get afew bottles of demineralised water

drain water system completely

fill with only deminaralised water

run engine and get hot retest voltage

mine dropped to .10 after this

so my problem was not bad earth it was the impurities in tap water that when it reach a hot temp circulating thru enigne cause an actual voltage

fwiw, pure water doesn't really conduct electricity.
it needs ions to do this. salts/minerals do this nicely.
most water has some kind of salts in it, which is why people say water conducts electricity, but technically they are wrong

it should have been no surprise that there was little conduction when you used demineralised water...

any reaction between water and the iron in the block will put ions into the water anyway.

other thing to check is the pH.. at certain pH, aluminium passivates, so you wanna be within that region

as much as i hate Wiki, i cbf looking up better references
http://en.wikipedia.org/wiki/Corrosion
http://en.wikipedia.org/wiki/Passivation

[Mos]

Galvanic corrosion describes this adequately.
http://en.wikipedia.org/wiki/Galvanic_corrosion
http://www.engineersedge.com/galvanic_capatability.htm

Earthing the radiator completes one side of the circuit. Impurities in the coolant complete the other circuit. Remove either or both to remove the effect.

So the answer to the OP is "insulate it".

Mos.