GTi-R Rusty brakes + acid

[Charlie Guthrie]

I would not worry about the rust, but the first few stops should be from low
speed. The rust film will leave quickly, but use the old pads to "break in"
the rotors first, then put on the new pads. Or....if you are not as lazy as
I am, use Muratic acid, available from most hardware stores on the disks.
Muratic acid is hydrochloric acid and it will "reduce" the oxygen in the
rust to leave a good finish. Auto restorers often use this acid for rust
removal. A few notes on the use of acid to clean metal: 1. allow plenty of
ventilation (outdoors only). The acid fumes will condense in any moisture
(inside your lungs, in the nooks and crannies of your car, etc. and will
cause harm). 2. The acid cleans the metal, but it also etches the surface
making it more sensitive to subsequent rust (it rusts faster after treating
until the surface is smoothed). Painters use the acid wash to prep fenders,
but then they often treat the fender with a rust inhibitor if it is not to
be painted right away (as within minutes, not days). 3. do not use the acid
near any other metal objects that you treasure (remember those fumes?) My
reading indicates that the fumes tend to settle onto surfaces and if there
is no rust to attack, it attacks whatever is there. 4. buy some acid brushes
to apply the acid or plan to throw away what ever you use.
5. ABSOLUTELY wear EYE PROTECTION and use rubber gloves. I use a face shield
and safety glasses. Many homeowner face shields are open at the top, and a
splash could get in over the top.  And wear clothes that you don't mind
loosing. I also keep a box of baking soda handy to neutralize the acid in
case of stupidity. If I'm doing a lot of work with acid, I also make up
about a gallon of baking soda solution to plunge my body parts into. After
the acid cleaning is done I use the backing soda water to rinse the treated
parts and to pour around any spills.
Despite the risks and hazards, this is my favorite rust removal tool. A
couple of notched down in performance is Naval Jelly which is phosphoric
acid.
Charlie Guthrie