Re: heater core failure; reading tea leaves post mortem

[Tom Jennings <tomj@xxxxxxx>]

On Nov 22, 2005, at 4:14 AM, farna@xxxxxxx wrote:

> Sacrificial anodes are as good as tea leaves in a car. In a  
> previous post I put in a link that explains. In a nutshell, it  
> works for marine and under ground pipe applications because the  
> water and soil will pass current and complete the circuit. There's  
> nothing but air around a car, so nothing to complete a circuit. To  
> top that off, rubber tires are an excellent insulator! Notice that  
> you haven't seen an electronic rust inhibitor for cars offered  
> lately? Apparently there is a law against it (federal) because they  
> physically can't work!!

You're 100% right; sacrificial anodes work, but require a path for  
current flow, eg. a metal boat sitting in water.

However, you could put a chunk of zinc in the top radiator tank, it  
would help locally, but that's not usually where the problem is, and  
if it is there, then you have some electrical thing grounded to the  
radiator instead of the chassis, and the radiator::chassis connection  
is poor (eg. loose bolts). Electrical cooling fans, it would be very  
bad practice indeed to ground the motor to the radiator!

Also when the zinc anode gets eaten, the zinc salts need to go  
somewhere -- and you probably don't want a zinc salt additive in the  
radiator juice!

No one ever changes the anode in domestic hot water heaters, either :-)





> On November 21, 2005 andrew hay wrote:
>
> > sacrificial anodes, usually zinc.  marine guys know all about
> > sacrificial anode systems!  talk to a powerboat yard that does repair
> > or construction.
> >
> > another thought - wrap the nipple threads in teflon tape to try and
> > insulate the iron from the aluminum manifold.
> >
> > ps. that web site talks about rust protection - which doesn't work -
> > and doesn't mention cooling systems.
> > _____________________________________________________________________ 
> > ___
> > Andrew Hay                                  the genius nature
> > internet rambler                            is to see what all  
> > have seen
> > adh@xxxxxxxxxxxxxxxxx                       and think what none  
> > thought
>
>
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