doocruiser

hi sorry dint see the msg.
basically give a light brush down,then paint on acid solution,leave untill metal becomes bright,then wash down with lots of fresh water,repeat with brushing and acid on areas where there is a lot of discolouration.
may also be a good idea to use an engine cleaner detergent first to remove any grease.
through brushing afterwards this process will give a bright shiny finish,can also use plastic kitchen scourers,for difficult to reach areas.
have fun
seasons greetings and enjoy koh lipi,last time we ware there was during the tsunami in kho lanta,that we missed by 30 mins after upping anchor.
remington and jojo and rthymstick are friends of ours in phuket if you know them,
alex

hi as noleex said alu is naturally anti corrosive,should be able to find stainless brushes and phospheric acid in thailand,only know phuket and langkawi but try industrial paint companies.
the reason not to use mild steel and brass is that they leave minute particles embedded in the ally which will cause corrosion.
though on a dingy not a big issue.
if you cant find phospheric use a very miild sulphuric acid mix(batteryacid) and was with water as soon as alu becomes bright.
cheers alex