Help with /5 Alloy Cleaning/Finishing

[Bonwit]

Hi, I just found this forum and am looking forward to getting sound advice from restorers who have gone before me. I'm beginning the reassembly of my /5 and I'm trying to figure out how to handle the finishing of alloy parts such as the rear brake lever and shifter. Currently, these parts are a smooth matte finish. I'm curious to know if when new, were these parts flat finished or polished?

Then there's the engine case. I've successfully cleaned the corrosion and grim using Eagle One Etching Mag Wheel Cleaner and a Scotch Brite pad. There are places however where the texture of the cast part has been rubbed almost smooth, and some of the parts are not really uniform in color. Is there a recommendation for imparting a uniform factory like finish to the engine?

Thanks!

[melville]

Fair warning--my bike and its parts were really crusty, and I was not concerned with a 100 point restoration. I'm kinda into shiny stuff. My thread on the old board covers this stuff in depth:

http://boxerworks.com/phorum5/read.php?3,36224,36224

You may need to set your old board preferences to flat view for it to make reading sense.

Also search stuff by user gspd on the old board.

I believe BMW intended a matte finish, but it doesn't appear to me like they went to the step of doing a clear anodizing to keep that finish. On the parts I polished I didn't have to spend as much effort getting through a layer of ano as I have on bicycle parts that I know to have a clear ano.

[Motorhead]

My first Beemer I used diesel to clean the motor it had beach exposer some white and some really black spots

with a scoth brite and diesel I rubed it when I cleaned it and let it smoke when I starrted it eventually it turned a gray color

Red is a diffrent aminal ,I used the eagle stuff and then just WD40 and eventally a penetrating oil soak the alum just drinks it

[boxertwinjeff]

For the engine block casting, & front & rear axle castings etc, I found a product
made by the WD-40 Company called 3 in 1 professional all purpose Cleaner & Degreaser.
You spray it on & it foams up, citrus based, you can hear it disolving the gunk, then you
hose it off.
On the built up grime, I sprayed the area liberally then scrubbed with a stiff toothbrush.
It lifted the grime from the pores of the castings with several applications, and without
creating smooth areas. Personally, I think a stiff toothbrush is more gentle on the surface
compared to scourers.
The finished look achieved was well worth the effort, a clean, bright even finish.
I've read how some guys respray the castings grey after cleaning
but each to their own I suppose. Have been advised to stay clear of acid etching products,
told they can be too corrosive on the castings.
Citrus based products seem to achieve a great result without being avasive. Jeff.

[DanielMc]

Check out Rub'N Buff - it's a craft product made with waxes and metal powder. I first heard of it when I ran a Guzzi - their castings are impossible to keep clean, and it was recommended on a forum. I finally tried it when I was looking to get the castings on my '76 R90S bike to a uniform colour. I degreased all the alloy, used a caustic alloy cleaner and then applied a small amount of Silver Leaf colour Rub'N Buff to engine, gearbox, final drive and sliders. Unbelievable. I've since recommended it on a UK BMW forum, and everyone who's tried it loves it.

[She'llbe]

How do we find the site of the UK based BMW forum?

[Bob Bennett]

G'day She'llbe
Try this link mate,
http://www.bmbikes.org.uk/Forum/index.php