the off the shelf rad flush has citric acid as one component.

any extreme, acid or base, will hurt the aluminium. copper rads can
be treated with a harsher acid, or take it to a rad shop an let them
do it. For the Al rad,  I'd buy some rad flush and fill the out of
van rad with solution and let it sit, then flush hard with water.

alistair

On 14-May-10, at 4:07 PM, Zoltan wrote:

I am trying to find a way to get the radiator soaked into something
that would lift the slime from the inside of it, so I can just blast
it out with water and compressed air.  I have a copper radiator and
an aluminium one.  They are both loaded with slime.
I know, I can buy a new one.  That's not the question now.  There are
many of us on the list who would like to know this.  And maybe it is
a good practice to rinse it sometimes, I guess.  It can be done while
still in the car.  Then we would not have to replace it.
I think of something acid or alkali kind.  Maybe there is one that is
already being used long time and I just don't know of.  One maybe for
aluminum one for others.
Anyone?