I don't want to start a controversy here :)

but not many p traps made out of aluminium.

Draino is a mixture of lye (NaOH) and aluminium chips, and when it
comes in contact with water the lye reacts with the aluminium chips
to produce hydrogen gas which helps in the process of clearing
drains. the heat generated by the reaction softens the plug material
and the lye also softens, dissolves, saponifies greasy plugs.

A strong solution of NaOH plus Aluminium  is a pretty well
established reaction :)

plastic pipes are fairly resistant to the concentration of lye used
in proper drain clearing application.

i'd really, really caution you in the use of lye with aluminium
radiators.

alistair

On 15-May-10, at 9:38 AM, VWBrain@aol.com wrote:

In a message dated 5/15/2010 12:24:55 P.M. Eastern Daylight Time,
albell@SHAW.CA writes:
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
Well we do mix it with water and I do know that of the dozen we have
had to do like this have had no bad effects.  that has held true for
more than 2 years for some of them.   Also isn't a lot of p traps and
such made from aluminium??? and even plastic???  as normal YMMV and
somebody always is a naysayer   !   but it has worked. but I do cover
my butt and tell the customer that I can't gaurantee anything doing
it like such  later  mark d