On second thought, scrap the two clamps and the grease idea.. the
grease may weaken the hose and the first clamp will isolate all of the
stress on the hose to a single narrow cross section and make it fail
prematurely... better would be to coat the dry aluminum with a good
high-temp stable(perhaps brushable silicone/RTV coating) and then
install the hose over it. Just a couple more crumbs for the table...

Jim Akiba

On 11/29/07, Jim Akiba <jakiba@bostig.com> wrote:
> Whoops forgot to answer to the "how to stop it" part... it's tedious,
> but loosening your clamps and moving the hose, thus removing the
> "stagnant" coolant(losing some too) between the rubber/AL should
> help... also using heavy grease and two hose clamps (one further up,
> before adding coolant should theoretically help. The idea being DON'T
> have any water/coolant in between the rubber and the hose at all. Not
> sure it's worth it though... healthy coolant and timely changes and
> hose replacements always seem to work for me.
>
> Jim Akiba
>
>
>
> On 11/29/07, Jim Akiba <syncrolist@bostig.com> wrote:
> > To answer the most important question, it's likely the lack of
> > movement of the coolant in that area.  Check out this abstract on an
> > sae tech paper titled "Investigation of Fluid Circulation Effect on
> > the Internal Corrosion Resistance of Automotive Heater Core".
> >
> > The Al-Si cladding they talk about on the cores would be roughly
> > equivalent to the common AL-Si alloys used in casting such parts as
> > water pump inlets etc, so I don't see any reasons the last
> > sentence(and more importantly its logical inverse) wouldn't also hold
> > true. If you are interested in the exact mechanism that causes this, I
> > can dig further.
> >
> > "An experimental test bench has been developed to study the effect of
> > flow on the corrosion behavior of the internal surface of heater core
> > tubes. The experimental device allows the electrochemical behavior of
> > the system to be investigated under different liquid compositions,
> > different temperatures (between 40 and 80�C) and different fluid
> > velocities (between 0.5 m/s and 1.5 m/s) at different test duration
> > (up to 100 h). The study is focused on the water side corrosion
> > resistance of brazed AA4343/AA3003*/AA4343 material, i.e., the
> > residual Al-Si cladding. The increase of the temperature has a
> > preponderant influence on the corrosion rate by comparison with the
> > variation of the fluid velocity. The increase of fluid velocity rather
> > limits the corrosion degradation."
> >
> > Jim Akiba
> >
> >
> >
> >
> > On 11/29/07, Zoltan Kuthy <zolo@foxinternet.net> wrote:
> > > Probably the most important question to answer is; what makes corrosion between rubber and aluminum?  The other is; how to avoid it?
> > > Although, I have put this question up more than once within a year, nobody even attempted to try to answer it, but ONE.
> > > This list is fighting and dreading this symptom the most, yet there is not enough knowledge to know how to stop it.
> > > Is there more than ONE out of the hundreds of members who knows, or at least think he knows?
> > > Anyone?
> > > Zoltan
> > >
> >
>