How To Clean Aluminium Parts

Hunnicutt Thessis1975 · Friday, November 19, 2021

Re: How to make alloy parts look new? Degreaser or cleaner recommendations.

to help with degreasing, buy a 20 litre saucepan, buy a $20 gas cooker thing, buy h/duty truck degreaser or similar, grab a cake cooling rack from the kitchen.
Fill pot with water to cover parts, put on gas cooker to keep warm and keep simmering, pour in far too much degreaser, put the cake cooling tray at bottom of pot, lower your alloy parts into the resulting steaming caustic solution, regularly stir water. Remove after at least an hour or two and allow to cool a bit, but while still warm, attack the part with green scourer (keeping it wet with some of the now-revolting liquid in the pot), hose off the loosened grim and give it another dumping. Repeat as required as the liquid is good for a few baths and you can also top it up with more degreaser. This removes most greasy shit tho the odour of the steamy caustic stuff will get a bit on the nose after a while.

cautions:
- if you simply rinse off the liquid some gunk stays behind, as the parts dry you'll get that white alloy corrosion/power on the surface
- after dunking it enough, scrub off with a scourer (under warm/hot water) as you rinse off the caustic stuff
- repeat the scrubbing with a new green thing (or wire brush) when dry. This should stop any white crud appearing on the metal surfaces
- be prepared to quickly attack it with a wire brush (see pic in earlier post) after the second dumping
- avoid shock cooling things, this tends to make stains a bit permanent
- put small items in a mesh bag or thread on a wire (you really don't want to go fishing for small things at the bottom of the pot).

I don't use the wire brush on any surfaces that sealing is important on (e.g. where the oil pump sits into the front crank cover on a 3S). After degreasing I usually finish those surfaces with W/D paper (sitting on a sheet of glass) to ensure the surface is flat.

If you feel really brave, give parts a spray with oven cleaner then hose off before it starts attacking the alloy. This approach will usually ruin anything alloy so keep it to steel things (sumps, windage trays, etc). Have even seen it used on a crank tho I have concerns about what it did to the bearing surfaces. I've only done it on heavily oiled things (engine splash tray coated in oil_dirt and some cast-iron ancillary brackets).