Topic: RE: Want an easy way to remove casting marks from CB750 hubs & other aluminum

[chewbacca5000]

Hey Team,

Looking for an easy way to remove the casting marks from CB750 hubs and other aluminum.  I am doing quite a bit of polishing on my current project and it is taking hour after hour of tedious sanding to get to smooth aluminum.

I noticed that even when glass beading the casting marks remain.  They are like tiny, little dimples that very similar to what happens when aluminum oxides.  In order to get a show polish this stuff needs to be fairly even.

Looking for something better than sandpaper.

[seanbarney41]

most folks start with sandpaper too fine.   You will sand your fingers off with 400 grit.  Sart with a file on the big nasties, then 100 grit on up...

[Jerry Rxman Griffin aka MuthaF'er]

Dremel is a good start then work your way QUICKLY down to sandpaper.

[754]

Machine the fins off..smooth look...

[Don R]

Lathe the round parts.

[Garage_guy_chris]

When i did the polishing for my 750 i decided to mess around and find a better way. In the end about the best way i could find was one of these oscillating sander multi-tool things. I started at about 120 and worked up to 400 then went to red scotchbrite then on to the wheels and polishing compounds.

http://d3ka0sx7noujy3.cloudfront.net/wp-content/uploads/2013/02/best-sanders-fein-multimaster.jpg

[chewbacca5000]

Lathe the round parts.

I used the lathe for the tappet covers and it was an improvement.  Really want to do the hubs with the lathe, but need a bigger chuck to hold them. 

I wonder if the 3m bristle brushes would help? 

[calj737]

Chewy - mount the hub to a spindle, then chuck the spindle in your lathe. A flat piece of steel, bolt pattern drilled, then a tube welded to the flat piece. Chuck the tube. Voilá!

If you opt to sand, use green scotchbrite pads to start in a dremel, rotary grinder, angle grinder. It's more than coarse enough. Then progress to red, then to grey. Then start wetsanding before buffing.

[Gamma]

This is how I did my front hub

http://forums.sohc4.net/index.php/topic,58276.msg631146.html#msg631146

[chewbacca5000]

This is how I did my front hub

http://forums.sohc4.net/index.php/topic,58276.msg631146.html#msg631146

Thanks for the tip Bill!  Did a front hub quick and easy.  Very simple to wrap the wire around the axle and put into the lathe.  I used the bolt holes so I can polish both lips without changing position.

Yours looks sweet, but I don't see the point in polishing the speedo or brake area as they are covered.

Thanks to you too Cal.  I might make a fixture done the road or not. 

Frank don't have enough room to cut off fins for rear hub, but can do front when my new chuck comes in.

[chewbacca5000]

This worked out pretty good.  For those without a lathe or drill press you could do the rear hub with 2 20mm pillow blocks, a 20mm pulley and a motor.  Any 1/2HP or better will do.