I've listed the tools and products which I found useful:
- Mac Allister variable speed 240v drill https://www.screwfix.com/p/mac-allister ... 240v/294gf
- Surface preparation wheel https://www.screwfix.com/p/spindle-surf ... tid=374636
- Nylon filament wheel https://www.toolstation.com/abracs-nylo ... ush/p42759
- Scotchbrite sanding wheel fine https://www.metalpolishingsupplies.co.u ... 2-section/
- Scotchbrite sanding wheel medium https://www.metalpolishingsupplies.co.u ... 2-section/
- Contour sanding pads https://www.toolstation.com/contour-sanding-pads/p10736
- Steel wool
- Autosol metal polish https://www.halfords.com/motoring/car-c ... 17257.html
- Autoglym wheel cleaner https://www.autoglym.com/clean-wheels
- Turtle wax https://www.halfords.com/motoring/car-c ... 35097.html
The process I followed was largely as per djw766's instructions, except I didn't renew the paintwork and I didn't lacquer over the newly cut surface. From speaking to the wheel refurbishers and reading various forums, I'd realised that the lacquer on bare aluminium won't hold up for very long at all, so I thought I'd try something different and just polish and wax the bare surface. The thinking was that as and when new blemishes appear, I can sand down that area and re-polish and wax without having to do a big overhaul.
I started by jet washing the wheels (not particularly effective) then using the Autoglym wheel cleaner spray and a brush to remove the brake dust and road grime. I was surprised how much less noticeable the corroded areas became after removing the brake dust and dirt.
Once rinsed and dried, I used the "surface prep wheel" which was the most abrasive of the wheels to clean up the diamond-cut surface (not the painted ones). It took off the lacquer, corrosion and old diamond cut grooves with ease but could easily damage/misshape the underlying wheel surface with too much pressure or if you use the tool at the wrong angle. This wheel is rigid so struggled to get into some areas. At first, the wheel wasn't turning perfectly true but once it had worn down a little it became more useable. For the more intricate areas including spokes and around the outermost "lip", I found the "Abracs" nylon filament wheel very useful. It was less abrasive than the surface prep wheel and because it is flexible, could get into tricky areas. I got the wheels to a state where there was no lacquer, no corrosion and no trace of the old diamond cut grooves as well as clearing the vast majority of surface pitting.
Careful around the valve - the abrasive wheels will cut through the plastic easily. Also, remove the plastic centre cap for the same reason. Wear safety glasses as bits do come flying off the abrasive wheel and the actual wheel at some speed. I accidentally caught the abrasive wheel on the tyre a few times but it didn't do too much harm.
I took the opportunity to hammer out a buckled "lip" where I'd kerbed a wheel using the blunt end of a cold chisel. The surface prep wheel was good at removing scored material around the lip from other kerbing incidents.
Next, I tried to remove some of the gouges/marks left by the two abrasive wheels using the Scotchbrite wheels. They weren't coarse enough to reduce the size of the scratches. Ideally, I'd have had another abrasive wheel which was finer grain at this stage. Or maybe a coarser Scotchbrite wheel.
For polishing, I used the scotchbrite wheels. They're not very durable so you'll easily get through one disc of each grit per wheel. You can cut out the "contour sanding pads" with scissors to replace the sanding wheels. I used some Autosol polish with the finer grain scotchbrite wheel as well as with the counter sanding pads, working my way through the grits. The surface turns dark grey when the polish is applied, but it buffs off when dry. Next, I used some steel wool again with some Autosol polishing compound. I wasn't sure which grit the steel wool and contour sanding pads corresponded to so I may not have done it in the best order. I also tried using a polishing sponge which was mounted in the drill, but it tore itself apart pretty quickly so I wouldn't recommend it. I buffed the polishing compound off using a clean rag.
Finally, I applied the turtle wax as per instructions using the damp applicator, letting it haze up, then buffing with a clean cloth. I did a couple of coats.
Left: Cleaned + polished; Right: Cleaned only.
Both polished
It took me a few hours per wheel from start to finish. Other than the brush marks/scratches from the abrasive wheels still being visible, I'm quite happy with how they look polished. I'm not sure how well they'll hold up given it is just the wax between them and the elements, but hopefully it'll be a while before they're looking as bad as they originally were.
I'll try to remember to upload some more pics in a month or so show whether or not the finish has held up.
