Topic: Getting the engine to shine...

[noobie dave]

Hey guys, I've got my 78 550k running pretty well so now it's on to aethetics.

The breather cover (on top of the valve cover) as well as the alternator cover are that aluminum(?) alloy and are all blotchy and old-looking.  What's the answer to this?  I'm assuming a polishing wheel or something like that?  Will the blotches polish out?  The rest of the engine still has its original silver paint and looks pretty decent, it's just the covers.

Thanks

[shizzomynizzo]

they are aluminum, wet sand them...start with a 500, get all the large scratches out, then move up to 800, then 1000, then 1200. if you want a chrome shine, go to 1500 and finish with 2000. Don't skip a step of paper, it will not turn out as good.

Then go to harbor freight and buy a cheap buffing wheel and compound kit for like 5 bucks. it attaches to your drill and will shine it real nice. you dont have to buff it, but it will really make a difference.

Do a search and you will find a lot of info on polishing the aluminum

[Porscheguy912]

if you take them off the bike bring them to a plating shop.
They have acid baths that they can dip them into to get the old clear coat off and then they'll buff them to a mirror shine.

I did this and it cost me $20 for macm2010's valve cover on his 750.

20 bucks saved me hours of frustration, hand cramps and raw fingers.

[T-Bone]

See, I want to go in the opposite dirrection and blacken everything out.  Oh man, I just forgot the name of the stuff you use.  "Engine Black" or something like that?  Comes in a rattle can, gives it a matte carbon finish look.  Anyone know what I'm talking about?

[nokrome]

  i have seen the light as far as polishing aluminum is concerned, a friend of mine has an industrial grade polishing set up in his shop, its basically a buffer on steroids that spins relatively slow with 12 inch dia wheels that are about 6 inches wide, the cool thing is that this thing is so powerful that you can really lean into it and not bog it down. ive spent many hours in my garage with my harbor freight set up with decent results but the other day i took a $20.00 ebay stator cover (you know,35 years old and covered in oxidation) and in about 20 minutes turned it into a beautifully polished piece (would have taken me 2+ hours on my harbor freight rig)  ill post pics soon

[azuredesign]

Anybody polished their cases? I'm debating on doing so, know it'll be a hassle to maintain, but wonder if it will retain a whole lot more heat. Sorry if this post is off topic a bit, but it's something I was thinking about, and this thread seemed like the place to ask.
Thanks for any thoughts!

[noobie dave]

Hey thanks for the replies guys.  As far as I can tell, there isn't any oxidation building up, to the point where i'd have to sand it off; it's just darkened and discolored.  I'll totally have to check into the "harbor freight" buffer idea-- i was figuring i would have to do something like that.

Also--I'd love to see pics of that "industrial buffer" job if you've got them!

[mrbreeze]

After a couple of years......all that hard work goes to sh!t. You really have to keep up on it and don't even think about clear coating it! I have thought about chroming but am not quite sure about how it adheres to aluminum.Seems to me alot of the parts that were chromed back in the day are now peeling,flakeing,etc......painting,powder coating are options but I like a bit of shiney on the cases at least!!!!

[rhos1355]

Hmmm, I feel there's a lot of truth in what you say mrbreeze, as I have had all my covers polished about a year ago and had sat in a crate since then waiting for me to get my arse into gear and rebuild the engine. And already there's a few flakes of oxidation here and there. May even require a re-polish.
But I find your comment about clear-coating curious. Can you tell me why you don't advise putting the clear coat on? I assume clear coating is something similar to what I've read about in other threads i.e. a kind of metal protective varnish? In the other threads, the guys that posted them were ecstatic as to the results produced.

[Gordon]

Clear coat, especially on parts that get hot, will turn yellow. 

[nokrome]

Clear coat, especially on parts that get hot, will turn yellow. 

true, it will also tend to flake off over time because the polished surface gives it nothing to adhere to
     thats just how it is, if you want to keep your aluminum looking good your going to have to re-polish from time to time

[mrbreeze]

Yeah....what Gordon and Nokrome said!!!!

[Porscheguy912]

After a couple of years......all that hard work goes to sh!t. You really have to keep up on it and don't even think about clear coating it! I have thought about chroming but am not quite sure about how it adheres to aluminum.Seems to me alot of the parts that were chromed back in the day are now peeling,flakeing,etc......painting,powder coating are options but I like a bit of shiney on the cases at least!!!!

The plater that i talked to said that you cant Chrome aluminium.
I didnt ask about nickel though.

 

[Gordon]

The plater that i talked to said that you cant Chrome aluminium.

Yes you can.  Hell, you can chrome plastic.  I'll be the first to admit I don't know much at all about the intricacies of the process of chrome plating, but I'm fairly confident in saying that the plater you talked to is full of B.S. 

If someone can provide evidence to show I'm wrong I'll happily take that back. 

[shizzomynizzo]

I have to agree with gordon, as I have a set of forged aluminum wheels that are triple dipped chrome.

I had them done to my 3rd gen camaro wheels. It is not cheap, and I'm unsure of the process, but aluminum can be chromed.

[Simpson]

My Experience:

Example: Chain Sprocket Cover, Clutch cover, Engine case
  I've had really good luck glass bead blasting covers that don't get exceptionally hot, then clear coating them.
  I've had really good luck painting covers that don't get exceptionally hot, then clear coating them.
  They do tend to stain/chip easy from spilled gas or maybe excessive heat if you use cheap rattle can
  Many times I buy NOS covers, for example my cb750 where its hard to duplicate polish
  Cylinder Head I use high temp paint only of course

I'm sure you can buy high temp clear coat but have not researched it. There are people out there who refinish to near stock quality, as I've seen them on Ebay.

[BobbyR]

Hey thanks for the replies guys.  As far as I can tell, there isn't any oxidation building up, to the point where i'd have to sand it off; it's just darkened and discolored.  I'll totally have to check into the "harbor freight" buffer idea-- i was figuring i would have to do something like that.

Also--I'd love to see pics of that "industrial buffer" job if you've got them!

The staining is what you will find after the white oxide has been removed. That stain can be sanded down as described and polished to better than new condition. I did everything when hauled the bike out of a basement. They are real easy to maintain if you get them shiny to begin with. Once in the beginning of the season I quickly rub them with Mothers Aluminum polish and once before I store it for the winter. It takes about 15 minutes and they stay bright.

[Gordon]

I've had a lot of success with Nev-r-Dull cotton wadding metal polish.  I sanded and buffed my valve cover and engine covers when I first got my K1 over five years ago, and I use nev-r-dull on them two or three times a year and they still look great.  This bike is no trailer queen, either.  It's my main means of transportation and gets ridden in all kinds of weather, and on salted roads in the Winter. 

[nokrome]

this is the stator cover that i polished on that big buffer (ill get pics when i go back to the shop next week), it was in your standard 35 year old condition when i got it,
   20 minutes on that buffer and this is what i got,
       lay in some black paint and its a really nice piece

[BobbyR]

After a couple of years......all that hard work goes to sh!t. You really have to keep up on it and don't even think about clear coating it! I have thought about chroming but am not quite sure about how it adheres to aluminum.Seems to me alot of the parts that were chromed back in the day are now peeling,flakeing,etc......painting,powder coating are options but I like a bit of shiney on the cases at least!!!!

The plater that i talked to said that you cant Chrome aluminium.
I didnt ask about nickel though.

 

Where did you find a plater, they are rare here in NY.

[Porscheguy912]

The plater that i talked to said that you cant Chrome aluminium.

Yes you can.  Hell, you can chrome plastic.  I'll be the first to admit I don't know much at all about the intricacies of the process of chrome plating, but I'm fairly confident in saying that the plater you talked to is full of B.S. 

If someone can provide evidence to show I'm wrong I'll happily take that back. 

I hope you are right! Maybe he meant "He" couldn't do it.
That would be sweet because i want to chrome my lower peg set thingies on my 78F.

[Don R]

Most of the old chrome on my new to me K0 peeling off. I would like to remove it if there was an easy [practical] way.

[bistromath]

It's a 4-layer chroming process. First you plate zinc, then copper, then nickel, then chrome. Results are sometimes good if you have a really reputable shop, but often bubble and flake after a few years. Surgically clean prep is essential.

[nokrome]

Most of the old chrome on my new to me K0 peeling off. I would like to remove it if there was an easy [practical] way.

  ive had good results with bead blasting old chrome off, works good if you are going to paint but if you want to polish it takes a lot of work because the blasting leaves a little texture on aluminum