Reclaiming an old damaged CB550F2/K3 rotor cover

[Oddjob]

Wasn't sure where to put this TBH, thought maybe start a project thread as this won't be the first casing I'll be trying to salvage but it will do here at present.

So here's the idea. I wanted to see if stuff that we think is maybe beyond saving can actually be restored to near to new. Not saying new or better than new, but maybe close to new.

The idea came about when I spotted an old box sitting on the top of one of my cupboards in the garage, I was looking for something else and thought that maybe I'll put it in the box, even though TBH I couldn't remember what was in the box So I got it down and when I opened it there were 2 500/550 oil pans or sumps in the bottom of the box, fully restored, all clean and ready to be ceramic coated. However on top of the them was an old CB550 rotor cover, I have a CB500 so I wouldn't be using one of these, main difference of course is that the 500 has a removable plate covering the field coil fixing screws, the 550 hasn't got this and has them exposed with the Honda logo embossed into the alloy. A little research showed that these covers aren't readily available and if you can find a NOS one it's not far off £200, so fixing one can save you a lot of money.

The cover was damaged, clearly the bike it was on had slid down the road, first on the lower edge and then when it had almost stopped onto it's side, the lower edge and the upper part where the logo is were both damaged, I'll let you decide how badly you think it's damaged, personally I'd class that as light to medium but make up your own mind. The rest of the casing was encrusted with really bad crud, not so much corrosion as baked on road dirt that was really hard. However this coating can hide a multitude of damage and it's not uncommon to find severe corrosion underneath.

Here's what I started with.



Close up of the lower edge damage. Notice how the Made In Japan engraving has been smeared across, some of the metal removed was actually forced down into the letters and proved a problem later on.



And the upper surface damage.



I'll do a separate post for each step to keep it tidy.

[Oddjob]

Post 2.

First step was to try and see how bad the damage was, how deep and whether the cover had corrosion under the coating.

I timed this step to see how long it took me to get to this point. Approx 3 hours.

Here's the initial cleanup.



Close up of the logo which was damaged.



And the area where the most damage was on the upper surface. It's still there but it's a lot better.

[Oddjob]

Post 3.

To this point I'd really been concentrating on the upper surface, it's the part most visible and the part most people see when they look at the casing area.

So now it was time to concentrate on the sides. See if the lower damage could be blended in. Again I timed it and around 3.5 hrs this time.

The edges were worked on with the aim of removing the gouges and trying to create a new edge, didn't turn out too bad at all.



Almost gone, just a few really small areas still to work on, some of them will require new engraving tools I've just ordered. These will remove those small kinks in the edging of the recess.#



The inside of the casing was pretty grubby so I thought I'd clean that up in the next step.

[Oddjob]

Post 4.

So the damage is almost gone, the sides now need some real attention, no major corrosion but there was some, especially on the upper most side, the one you see when you look down from the seat. The front edge of these casings seem to be the most prone to stone strikes and is usually the area that requires the most attention, this one wasn't really bad but there was some damage that needed sorting out.

So another 3-4 hrs of just smoothing down what had already been worked on, progressive sanding down from 40 grit to remove the gouges to 1000 grit eventually. At this time just the logo plate is down to 1000 grit and feels like a pane of glass, really smooth. Should polish up well. The sides are at around 120 grit at this point.

And here's where we were at this point.





Damage gone, just some really small points to fix when the new tools arrive.



And the other sides of the casing.





And finally the inside cleaned up.

[Oddjob]

Post 5.

Didn't do much for around a week as the weather changed and I like to do stuff like this outdoors in the sunlight.

This part took me a while, there's about 10-12 hrs invested in this at the moment, this part took me another 5-6 hrs, mainly because it's this bit that determines how it will turn out, get this part right and it makes the polishing part so much easier. I reckon less than 1 hour to polish this to match chrome. At the end of this step the cover feels like it's made of glass, it's ultra smooth. I tried a small 1mm drill in the Dremel to see if I could clean out the Made In Japan engraving, it sort of worked but I should have bought the right tools for this and it was at this point I decided to buy some proper engraving tools, I'll tidy this up when they arrive, hopefully.

So here's where we are right now. After this point I'll repair all those small kinks etc, redo the logo and then polish it. After that I'll repaint the HONDA part as it was originally. I also think I'll paint in the Made In Japan part as well, I'm also thinking of painting the outer recess ring, if it doesn't look right some paint stripper will solve it and put it back to how it is now.

It's not perfect, there are numerous swirl marks left by the sanding brushes but these will go when it's polished.. There are also a small number of really small dents still, stone strike residue, I'll see if these polish out and if not I'll go over them again with the sanding brushes until I'm happy. The dark colour on the surface is actually polish coming off the edges of the sanding discs, I think they are impregnated with buffing compound and when they get hot it tends to transfer to the metal.

[Oddjob]

I'll post again when it's finished.

And no, it's NOT FOR SALE. And NO, I'm not interested in doing yours, before you ask. This is not beyond anyone on here, have a crack at one yourself and see how easy this is, yes it's tedious, yes it's long hours but hopefully the results will make it worth while both financially and in your sense of self worth.

[McCabe-Thiele (Ted)]

Pretty impressive restoration there Ken as always - on my 500 it's the separate outer badge that has a fair bit of damage to it - not sure if its recoverable.

[Oddjob]

I've bought a pretty damaged one of those Ted, dented and gouged. That will be my next little project and will appear on this thread when it's done, if it comes out ok that is.

I intend to heat the alloy up until it's pliable and see about knocking the dents out from behind.

If it comes out ok I'll polish it to match the outer cover and sell my NOS badge.

[McCabe-Thiele (Ted)]

My badge has chunks out of it with general scuffing probably from a riders boot.
The bottom rear mounting peg is a bit out kilter as well.

I did think about just a general polish & paint it all over in silver.



500 alternator badge by Macabe Thiele, on Flickr


.500 rear alt badge by Macabe Thiele, on Flickr

[Oddjob]

Pity you can't find someone to drop some alloy in the gouges Ted. The rest looks easy to fix.

[McCabe-Thiele (Ted)]

I could build it up with some JB Weld or Epoxy resin?

[Oddjob]

If you were painting it then yes, that should work. Flat the rest down with the discs though or you'll see the marking through the paint, you can shape the JB weld etc with the discs as well.

[Oddjob]

Polished the cover today. Came out ok, not 100% happy with it but I suppose it's the best it can be.

I've cleaned out all the polishing soap with thinners and I'll do the paint maybe tomorrow, just waiting for a special tool to do this to arrive. I've cleaned up the engravings as well.

[DomP]

That's a bit more than OK Ken it looks fantastic, it's got me thinking though, my 550 must have a 500 cover on it.

[Trigger]

That's a bit more than OK Ken it looks fantastic, it's got me thinking though, my 550 must have a 500 cover on it.

If yours is a CB550 F1 it came with the 500 Four cover