Yes, I agree.  Drano and similar products are a combination of sodium
hydroxide and either aluminum and/or zinc (plus some other stuff, salts
mostly). When added to water, you get an instant chemical reaction that
produces heat, hydrogen gas, and some  other products/effects. That
bubbling when you add it to water is the release of hydrogen gas. I
would be very careful using  such products in systems with aluminum
components.

Oh and the liquid Drano, is  even worse in my opinion, it is a
combination of sodium hydroxide and sodium hypochlorite (chlorine bleach).

Best solution (sorry bad pun) for a safe and effective cleaning is to
take it to a radiator shop and have them rod it out. They will
chemically and mechanically clean it and can tell you if the core is
good or not. Costs a bit more than some DIY magic solution, but it is a
known process and the best way to fix the problem. Nothing worse than
having to R&R a rad more than once, just to try and save a few pennies,
(well except for that cracked head because the radiator dumped all your
coolant before you realized things were getting too hot).

Just my HO

Alistair Bell wrote:
> this "advice" I will give you is only based on my other experiences
> with strong bases and aluminium, and not meant to pooh pooh draino
> advice, but be careful with draino, its lye, sodium hydroxide, and
> strong solutions will eat the aluminium up lickety split.
>
> I'd be very very careful.
>
> alistair
>
>
>
> On 15-May-10, at 8:55 AM, Zoltan wrote:
>
> Aha, Draino.  That sounds like something that unclogs stuff.
> Zoltan
>   ----- Original Message -----
>   From: VWBrain@aol.com
>   To: thewestyman@GMAIL.COM ; vanagon@GERRY.VANAGON.COM
>   Sent: Saturday, May 15, 2010 8:35 AM
>   Subject: Re: What to soak radiator in to dissolve slime
>
>
>   In a message dated 5/14/2010 7:12:24 P.M. Eastern Daylight Time,
> thewestyman@GMAIL.COM writes:
>     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?
>   hey guys  we have used draino on these and heater cores without
> any problems.  normally we let them soak for a couple of days.  these
> were done this way because the customers couldn't afford to fix them
> right.    So far none of them that was fixed this way have had any
> problems  later  mark dearing
>

--

Marc Sayer
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Oakridge, OR USA

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