Topic: Tools For Engine Polishing?

[campbmic]

A few months ago my bike was in a fire. I've pulled the engine and removed the heads to replace the gaskets (had an oil leak before the fire). I used a wire brush on a drill to clean up the engine.

Last night I spent about 2 hours sanding by hand a part of the engine case using grit 250 > 500 > 1000 > 1200. I then used a black, brown, and white aluminum polish and got a really great result. The problem is this took a lot of sandpaper and just murdered my hand.

I purchased a really nice drimmel with some polishing attachments, I also have the drill with polishing attachments. Is there anything similar that I can purchase to attach to the drimmel and drill instead of using sandpaper? I know there are certain 3m discs, but dont know much about them.

Or if anyone has a different route I could take I'm all ears.

Lastly, I've rebuilt the top end previous and feel comfortable with it. The gasket kit I purchased has top and bottom. I was thinking about taking apart the bottom end to split the cases and make it easier to polish. Do you guys think the bottom end is more difficult to rebuild? Are there any specific tools required?

Thanks for any advice!

[Bodi]

Splitting the cases means taking a lot of things off the outside and then a lot of things out of the inside... and remembering how they go back. Depends on how much you value polished cases. I think tearing down to bare cases and covers then having them soda or vapor blasted would be the best way, if you're going through disassembly/reassembly then having them cleaned up well with blasting before trying to polish them would make a lot of sense to me.
Even very fine abrasive media in a sandblaster will give a good base finish but I haven't ever polished them, I put "GunKote" on a few engines some decades ago and wanted a clean surface for that. BTW, that stuff is great.
In my limited experience, polishing does not have many shortcuts. A strong arm and a case of beer plus a lot of time...
I have a polishing lathe but that's only good for relatively flat things. A cloth disc on a drill will float around corners and get into the fins a bit. More aggressive compounds will round off sharp corners fairly fast with power tools.
In general, polishing tends to be a rabbit hole you go down and never come out of. There is always some difficult to get at stuff that just needs "a little more work". By the time you finish the last part, you'll see flaws in your first ones and start over to give them a "touch up"... and repeat this a few times. Finally you'll realize that the aluminum alloy just will not hold a polish, and that a polished surface won't hold a coating.

[90blacknight]

Ok, I just went through this. As the previous poster said, polishing can be a rabbit hole you never climb out of. Going the sand paper route can take ages. As far as polishing aluminum, at first I started off wet sanding with 600 grit and moved all the way up to 3000 grit cleaning the aluminum between each grit level, then using aluminum polish. No sense going below 600 grit on these covers. You'll just be putting deep scratches in it. Well this took way too long! Now, Mother's Aluminum polish is great! I was able to go 600 to 800 grit, sometimes 1000, then going straight to Mother's Aluminum polish, using a hand held drill with a punch of polishing wheels (it's what I have). I'm very pleased with the results. Is it as perfect as the whole sand paper route to 3000 grit? No, but it works for me.

[754]

Cratex rubber abrasive points will help.

[campbmic]

Ok, I just went through this. As the previous poster said, polishing can be a rabbit hole you never climb out of. Going the sand paper route can take ages. As far as polishing aluminum, at first I started off wet sanding with 600 grit and moved all the way up to 3000 grit cleaning the aluminum between each grit level, then using aluminum polish. No sense going below 600 grit on these covers. You'll just be putting deep scratches in it. Well this took way too long! Now, Mother's Aluminum polish is great! I was able to go 600 to 800 grit, sometimes 1000, then going straight to Mother's Aluminum polish, using a hand held drill with a punch of polishing wheels (it's what I have). I'm very pleased with the results. Is it as perfect as the whole sand paper route to 3000 grit? No, but it works for me.

Really great results! I had some pretty deep scratches so I started with 250, maybe I didnt need to go that far. It sounds like you did it by hand, is that correct? Any tips for getting into the fins or those hard to reach places?

[Inkandboater]

I wouldn’t ever use sand paper unless you really had to.

First hit it with soapy water and a REAL brass brush
Then, Go with 0000 steal wool and barkeepers friend. Keep scrubbing w the steel wool and bar keepers friend a few times over.
Also NEVR dull is a good product for certain stains and applications.
Then hit it with your choice of polish.
I use mothers and blue magic. Lately I’ve been using the Blu magic more.

You’d be surprised how much you can do by hand.
But of course to finish it off using buffing pads and a drill will make everything shine to no end


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[low-side]

If you just want a nice shine, I'd get everything very clean and then use cotton buffs with black, red, and white polishing compounds.  These won't address deep scratches or pitting though.  If you want to address those, that's when the shaped miniature files and sandpaper come out.  Like folks have been saying, don't go too far down the rabbit hole; I like to remember that just like I have scars from living a life, so too does my bike.  Gives it character.  Personally, I polish engine covers but paint crank cases; Honda never meant for them to be bare and the finish of the castings usually shows it. 

[Don R]

 I've used a burgundy scotchbrite flap wheel. It has sandpaper between the layers and it works quick. Probably good as a first cut. Then various colors of scotchbrite. Strip the clear coat off first.  I have a polish called Green Dragon, and no it's not marijuana and everclear, that's a different green dragon. Not sure where to get it except a guy I race with anyway, it's awesome. Rub it on, let sit and polish off. Rough cases apply with 0000 steel wool. Maybe amazon shows it.   
 Edit:  highway shine co. They appear to specialize in truck products but have the green dragon and anything else you can imagine to polish with.

[90blacknight]

[/quote]

Really great results! I had some pretty deep scratches so I started with 250, maybe I didnt need to go that far. It sounds like you did it by hand, is that correct? Any tips for getting into the fins or those hard to reach places?
[/quote]

Only the covers were polished.  The engine block/head were painted with high heat engine paint. No way I would polish those!

[Bankerdanny]

250 is too course. When I polish I start with 320. A certain amount of hand work is almost unavoidable unless you have a really well setup shop. You might consider an inexpensive polisher setup from Harbour Freight, which makes getting the deep shine less work.

As far as the actual cases go, you really can't see most of the case anyway, i wouldn't go to that extreme. Just given them a good clean and a fresh coat of paint and save the polishing for the outer covers and valve cover.