Topic: First attempts at Polishing Aluminium

[dgilling]

I didn't even know this was possible Okay well i kind of did but dang!  i want my bike to look that shiny! somebody do mine!

[moham]

Everyone seems to understand the basic steps . i.e
1) - 200 - 250 grit paper to remove scratches and oxidation, or alternately glass peening.
2) - 300 - 400 grit to remove the paper scratches of the first sanding
3) - 800 - 1000 grit to remove scratches of previous step and to prepare surface for polishing

For the sanding stage, ok to use random orbit or palm sander or all need to be done by hand?

[Terry in Australia]

I wouldn't recommend it, but if you're game, try the palm sander with fine grit (400 up) paper and you shouldn't do too much damage.

I either use paint stripper or bead blast to remove the old coating and other burned on crap, then just polish, but I guess abrasive paper is good for rubbing out scratches in the alloy. Cheers, Terry.

[Tower]

Trying to sand curved aluminum by using a rigid flat surface is bound to create flat spots.  I'd reconsider using even a small (palm) sander.  Besides, watching as your hard effort slowly turns a tarnished, pitted and corroded piece of metal into a brilliant sparkling thing of beauty is very gratifying and inspiring.

[Terry in Australia]

But it's just so booooooring!

[Tower]

Would it help if you thought of it as zen-like meditative?

[Terry in Australia]

I don't think so, I remember spending hours polishing my old K1 cam cover back in 1982, my mate just had his chromed, I wish I'd done the same.......... 

[moham]

I should have known there would be nothing between me and many hours of physical hardship. Thanks for the info.

[Tower]

Terry, you should be glad you didn't go the chrome route...galvanic corrosion and all, means its basically a one-way decision.  You can sand and polish many times, but not so with chrome.  Once the redox reaction begins, and its inevitable, becuase chromed aluminum alloys have a high anodic index (0.80v - 0.95v) or about 3X - 6X higher than the advisable tolerance (between 0.15v - 0.25v).  In other words, that chromed piece quickly becomes trash.  By the time you spot the bubble or flaking chrome,  if pits haven't already become perforations, they may still be too deep to remove.

[Terry in Australia]

Terry, you should be glad you didn't go the chrome route...galvanic corrosion and all, means its basically a one-way decision.  You can sand and polish many times, but not so with chrome.  Once the redox reaction begins, and its inevitable, becuase chromed aluminum alloys have a high anodic index (0.80v - 0.95v) or about 3X - 6X higher than the advisable tolerance (between 0.15v - 0.25v).  In other words, that chromed piece quickly becomes trash.  By the time you spot the bubble or flaking chrome,  if pits haven't already become perforations, they may still be too deep to remove.

Well you're probably right mate, I've got a couple of chromed covers and they're pretty bad, but my mate Dave has still got his K2, and 20 years on, his plated parts still look fantastic. I'm sure they'll turn to crap eventually, but like me he's got heaps of spare covers, so if they do start to bubble he'll probably just get another set chromed, and worry about it again when he's 70-ish....... 

[Johnie]

Finally finished my last cover, the stator.  Here is a before and after picture.  I used no sandpaper, only my Sears buffer with red, green and white rouge.  However, I did not want to ruin the nice black OEM black paint around the Honda logo, so when the cover was done I taped off the logo and used 4,000, 6,000 and 8,000 paper on the HONDA logo only.  Turned out fine for me...

[Bob Wessner]

Very nice John. Want to come over and do mine?

[AOD]

I spent about 2.5 hours on my CB this Sunday, it all started with me getting tired of looking at the non-polished chrome exhaust canister.  I started on it, worked up the pipe, decided to hit the cases and forks too.

My cases were greying and getting cloudy...I didn't want the bright shiney look, so I polished them by hand with Mother's aluminum and mag polish.  It took quite a bit of buffing by hand, but they came out pretty nice.  I'll snap a picture and post it next time I can get the bike out in daylight.

I only mention this for those that don't want to take their bike apart to polish it or make it look better.  You can make it look boatloads better with some elbow grease and time.

~Adam

[Johnie]

That is a good point AOD.  Can be done with the stuff on rather than not at all.
Hey Bob...thanks for the tips on the meter board restoration.  It went very well.

[Tower]

Nice finish on the stator cover, Johnie. 

Has anyone tried tumble polishing?  Walnut shells and jewellers polish? 3 days in a spinning drum?

[JAG]

so what is this red green and white "rouge" everyone is talking about??  And where can I get it? Also, is this Aircraft stripper from Walmart, literally called "Aircraft Stripper" on the container?  Just wanted to make sure, thout about tackling the project tomorrow..

Thanks

Jonathan

[Johnie]

Yes, it is called Aircraft Stripper and is wicked stuff.  I think you can get it in spray or can from Walmart.  Make sure you do it outside or at least in a well vented area.  And be sure to wear rubber gloves it burns the hands.  The red, green and white rouge is available at Sears or probably anywhere that sells buffing wheels.  The rouge is what you lightly apply to the buffer.  The colors signify different grit strength.  Red is rough, then green will take it down more and white for the final buff.  There is other colors available depending on how bad your stuff is.  I just used teh red, green and white.  Got my info on polishing from this board too.  It worked well for me.

[JAG]

okay!!  Well I know what I'll be doing tomorrow!!

Thanks for the info..

[Johnie]

Forgot to mention, you need a dedicated buffing wheel for each rouge.  You can not use the red wheel with the green rouge, etc.  And remember to use a putty knife once and a while to get the hardened rouge off the wheel.  And where gloves or you will burn your hands.  Just a few tips I appreciated from this board.

[JAG]

Also very important to know...  Well.. As far as specifics.. When you say buffer wheel, is there different kinds. What do you suggest?

When I think of a buffer wheel, I think of what I use to put that wax/shine on my automobiles..

Jonathan

[JAG]

Again I apologize for my ignorance...  What is an easy way to get into those fin-like sections where there is a tight fit? Would it be easier to paint it with some high temp paint.. I was thinking about doing it anyways.. Just painting it black that is..

[troppo]

i was wondering the same thing (if your talking about the fins on the barrels)...
but i thought when i do get that far, i`d probably paint between the fins and polish the edges if i polished them
cheers
troppo

[seaweb11]

Like this

[troppo]

niiiiiiccccccceeeee
now if only i can manage that standard, ill be very happy when i get that far

[Johnie]

JAG...here is a picture of my set-up.  Nothing fancy but gives a great finish.  6 inch cotton buffing wheel x3.  I also take a marker and write on the side of each wheel what color rouge it is for or you will get them mixed up.  Oh, along with those gloves you may want to also get a pair of goggles and dust mask or you will be coughing all day from the dust.