Hot Rods Vibratory or hand polish raw aluminum castings

If I had something better to do with my time, I likely wouldn't have bothered with it. I had already polished the aluminum driveline soooo why not? I didn't worry too much about the nooks and crevices, as it tucked under my roadster where no one can see it other than the undercar cam at Mecum someday.

Wheels are easier than hard parts like trannys, QC diffs, that hogs head adapter above...They are of a different alloy me thinks, they have a tendency to pop under the heat of the buffer and there are surface imperfections you cannot illuminate. They weren't intended to be polished, the OP's wheels are and are much easier to work with. My advice for the OP is to polish the rear barrel of the rim, the part that no one sees. Great place to play. Start with just the lip, if you like it, go for the rear rim, then proceed to the fronts. I did a set of wheels for my Camaro (new ET 5 spokes) and the backs turned out prettier than the faces (which I was forced to re-polish as a result).

 

@Bandit Billy I'll say it first; you are one sick individual!

 

Oh, if you were only the first.

 

I also have the Bandit Billy sickness. I have been seen polishing washers on a late Saturday night.

 

20+ years ago when I decided to do my own polishing, I bought what I thought was all that was needed. The big buffer, 10" buffing wheels, various compounds and sandpaper... lots of sandpaper. It quickly became obvious that sandpaper alone wasn't the answer for pre-polish prep as getting into nooks and crannies with it was very difficult if not impossible in some places. Any corrosion that's left will quickly return. To flesh the story out further, at the time I was buying/rebuilding 'vintage' Yamaha '78-82 XS/XJ 1100 motorcycles. A labor of love more than anything, as while I made some money on every one, my calculated wages were third-world levels... LOL.

Anyway, I'd buy neglected bikes that had quit running, usually needing a valve adjustment (DOHC four with shims and buckets) and/or a carbs rebuild/sync to bring them back into proper running order. Fairly low parts costs, but lots of labor involved, about $1K at a bike shop. There were transmission issues also (popping out of 1st or 2nd gear) from owners not shifting them right but that was a no-parts-cost repair (some creative grinding on the dog teeth with a die grinder would fix that) but getting the trans out to work on it without splitting the cases is a major PITA (Yamaha claimed it can't be done...).

But one constant was that every bike was 'cosmetically challenged'. Painted stuff could be repainted, and their chrome quality was pretty good (even if the pre-plating prep work left something to be desired) and would usually clean up. But the polished aluminum bits were always a mess. Rock chips, scrapes, failed factory clear coat that allowed corrosion to get under it, or my personal favorite, an owner who painted over the whole mess trying to hide it. I tried chemical strippers (sloooow, stinky and messy) for the clear coat/paint, but the sandpaper was even slower. There had to be a better way... so I go looking.

Now, I live in a podunk town, so I try the local auto parts store. They have a 3M kit with an arbor, a couple of Scotchbrite discs (AKA surface conditioning discs) and five or six sanding discs. Cost was about $16 IIRC or about $1.80 each disc. Keep in mind some of these castings are pretty intricate with a lot of detail. So I give this a try...

It quickly becomes obvious that the sanding discs are waaay too aggressive to do this detail work. But the Scotchbrites? HERE is what I've been looking for! These will remove all of it in one go without taking the detail with it. A HUGE time saver over sanding. In most cases, go over the part with a fine blue disc, then follow up with a very fine gray disc and you're ready to polish. There is a caveat however... I use the edge of the disc for the detail work. A fresh disc will work very well, but the edge wears quickly and loses effectiveness. So I'll do those spots first, the face of the disc is still good for larger areas.

Ok, I've found what I need, now I just need a better, lower cost source. I drive into Tacoma and find several places that sell these, but none have bulk quantities, and all want $1.50 each for them even in bulk. Ouch! So, off to the internet... I find Keen abrasives online out of Canada. They were selling direct to consumers at the time (unfortunately, no longer) and in bulk were only about $.50 per disc. Much better price! As far as quality/performance, I didn't notice any material differences between those and the 3M discs when directly compared. I order up a couple of hundred, life is good! How well did they work?


Here's eight parts (actually thirteen as I didn't show both pieces of the 'pairs') that I prepped and polished in about eight hours start to finish. I'll be the first to admit I didn't try to attain perfection, but Jap castings from that era aren't the best. Running into voids or 'stuff' in the metal isn't uncommon, and blending out gouges or deep scratches without materially changing the shape of the part can be difficult to do in some cases. I'll note that all but the fork sliders were originally 'fully' polished; those were only partially polished but now have a full polish. There wasn't much sanding done of these parts. The two 'Yamaha' engine covers had scratches on the logo face, quickly leveled with a 6" 400 grit sanding disc and one of the sissy bar braces (bottom of the pic) had a long scratch longitudinally that I had to blend out, same thing.

Then there was these wheels...



These are sand-cast, so they're fair bit rougher than a die-cast part. The silver areas are only machined, not polished. I had to use the full tool spectrum on these because I modified them; files, die grinder with a burr, sanding discs before going to the Scotchbrites. I passed on doing the inside recess on the spokes, those areas got silver paint.


I didn't keep track of the hours on these... I didn't want to know...


I even polished the stainless rotors. I was pleased how they turned out, but I'll never do another set... LOLOL

As I mentioned, Keen no longer sells small amounts directly. They do have a presence on eBay however, but not much in the 2" roloc Scotchbrite-type discs. All I could find was a 'kit' with 25 each of brown, maroon, blue, and gray discs (100 total) for $70, or .70 per disc. The 3M discs can be found in a little better selections, but prices are around about $1 each. I saw all the 'other' brands (or unbranded) but now know to stay away. Maybe I'll try contacting them and see if they'll mix that kit because I surely don't need a ton of brown/maroon ones...

 

That is the most important part of polishing be it metal or paint, don't count the hours. Nice polishing Steve!

 

Hand jobs all the way for me.

 

I do mine the hard way by hand too, I need to try these machines some of you guys are using, cut the hours and fingerprint loss down

 

if you know anybody that bracket races ask them .seems like there is a racer at every track that polishes as a side hustle