Metal finishing

[jfjfjf2]

I'm removing some aluminium castings (rocker covers alternator bracket etc) in order to polish them. I've not yet had any success in finding glass or plastic bead blasters in my area, but if I can, would this be a good way to proceed? Failing that, is it a matter of wet and dry paper starting at 180 and working up to 1000 grit and final polish with mops? This would be easy enough on the rocker covers but very difficult on the brackets. Help, please advise.

Thanks,
Julian

[TallPaul]

You should get away with sanding & then polishing. I'd only use something as coarse as 120 for really rough casting marks, otherwise just use 400, 800, 1200, 1500 then 2000 and then use coarse cutting compound and work down with finer grades until you use a metal polish for the final buffing. It's generally pretty easy to sand & polish ally, I doubt you'd need an electric mop, but try on an easy bit first.

[jfjfjf2]

Thanks for the reply. Once I have a finish I'm happy with, is it a good idea to use a high temp clear engine enamel to make upkeep easier, are there any downsides?

Thanks,
Julian

[TallPaul]

I've never used a clear engine enamel, but I can foresee a couple of problems...
If any of the compounds or polishes you use have silicone in them, you'll struggle to get a paint to stick. You really need to use a self etching clear so it adheres to the ally, a wheel lacquer "may" do the job.
I have used normal 2k clear on polished ally parts before, but I sold the vehicle within a few months, so I cant comment on its durability- I doubt it stayed on for long though!
You might be better off repolishing the stuff every couple of months.