Engine Case Sanding

[buster]

Just wondering, because I have already done one piece by hand, if I took all the same sand paper 400, 600, 800, 1000 and steel wool 0, 00, 0000 and then buffing wheel....

Could I use a non-orbiting palm sander? Cause man do my fingers need a break.

Any help would be appreciated.

[CA180]

I think it depends on whether its a random orbital. Radom sanders will leave all kinds of marks in the metal. Still though, when you polish aluminum you usually sand horizontally then go back with a finer grit vertically, then go back with even finer horizontally again. Atleast thats the way I've always done it.

[Bruno]

You might be able to replace some of the early steps if you are going for perfection. I use abrasive brush wheels made by Dico (not metal brush wheels), although they won't cover all of the steps, just the early ones. I got them at ACE Hardware. They come in 3 varieties. Extra Coarse (Gray), Coarse (Orange), and Fine (Blue). I'm in the process of polishing my aluminum too. Only use the Extra Course for REALLY bad, deep oxidation. You'll end up sanding that out with 150 grit. I'd say the Coarse is about like 320 grit and the fine is somewhere between 400 and 600. After that, it's back to the hand work. If you decide to pick up a wheel or two, test it on a spare piece of aluminum just to make sure you are happy with the result. On my GS850 rear hub, I used my drill and went from course to fine to a buffing wheel with tripoli then to white rouge and it looked good enough for my taste. Not perfect, but pretty darn good with about half the effort or less.

[Dink]

Use a bench grinder; 8" for preference. Get a taper for it, then purchase a set of wheels and polishes.
Sissal is coarse, stitched cotton is medium, & loose cotton is fine.
Use these with the appropiate polish sticks and there is no need to sand at all.
I may mention I was a metal polisher in an earlier life.

Dink

[Bruno]

Hey Dink,

What polish do you use on sissal? Also, what is a taper? What's your best tip for getting out deep oxidation?

[Nessism]

When cleaning up the cases on my 550 I used 220 grit in places where the corrosion pitting was deepest. Worked my way up to 600 then switched to Mothers aluminum polish. Hands were tired for sure – use latex gloves to keep your hands from turning black. One minor trick I used was to roll the paper around an old sharpie marker so I could bear down around the covers mounting lugs without destroying my hands. Machine polishing would be the ticket but how does one get at the nooks and crannies around the mounting lugs?

Main question now is what kind of paint will hold up to chemicals and heat of the engine. Used VHT header paint before and the finish looked bad and turned yellow. Regular automotive clear sprayed real nice but is not durable – chipping off where the screws dig in. I think I’m going to try some clear from Por-15 to see if it’s any better. Not cheap but Por-15 seems to make good stuff.

[renobruce]

Why clear them at all? Being in California, your finish should hold up well. Just hit it by hand with some Mother's every now and then, and you should be good. My polish job is holding up very well without any clearcoat. Here are some recent pics:






BTW, your bike looks great!!

[Adler45]

http://www.lauerweaponry.com/index.cfm?Category=270&Subcat=DuraHeat%20Clear

Lauer Duracoat is awesome stuff. It's not paint, and we gunsmiths love it. Only problem is that it takes a while longer to set that regular paint. But aggressive gun cleaning solvents wont touch it, hell you have to sandblast it off and the hi temp clear goes up to 1200 degrees. You just have to make sure that you have all oil and wax off of the metal first. I use plain old brake cleaner and have had good results for many car trim parts as well. Once I got my dads 39 Ford trim all polished it got dura cleared and has held up fine.

[saffa]

that gs thou looks sweet RB .....