Letter 10917

How to polish aluminum for motorcycles to chrome like finish 

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Could you please advise me on how to polish aluminum motorcycle frames n rims n tools needed n what type of sandpaper 2 use to get chrome like finish n stripper to strip lacquer coating.

Thanks greatly,

William N [last name deleted for privacy by editor]
- Bronx, NY

THIS IS NOT AN EASY JOB< BE WARNED>

1. Remove lacquer with furniture paint stripper.

2. Start with relatively rough sand paper. Use something rough enough to take out all existing scratches. Move to the next finer grade. Sand in a different direction from the first grade. Sand until all scratches from first grade are gone. Move to the next finer grade. Sand in a different direction from the first grade. Sand until all scratches from second grade are gone. Repeat this process using finer and finer grades until you get the finish you want. Most jewelers do this for six or seven times before buffing. For a motorcycle frame, each sanding will probably take an entire day. You may also need to buff with a buffer and jeweler's rouge to get a true mirror finish. Immediately coat your part with spray clear lacquer, use several coats. I would suggest practicing on flat parts before attempting something as difficult as wheels or frames. Ultra-fine sandpaper is available in most auto parts stores. Use wet-dry sandpaper so you can wash the aluminum dust off the sandpaper. WEAR! A DUST MASK! Aluminum dust is not a good thing to breathe.

Personally, I'd suggest looking at powder-coating your parts at a shop, instead. Very cool look, reasonable price, much less work.

Good luck,

Bob Z [last name deleted for privacy by editor]
- Bohemia, NY

Use a wet dry sand paper and a mild solvent together if you keep the sand paper good and wet the process will go a lot easier, you might want to wear gloves and goggles.

S Taylor
- Thunder Bay, Ont., Canada

Hi, I have a 2000 Yamaha r6 and wanted to polish my frame and swing arm. The problem is that I don't know what tools I will need or where to begin. I know that Yamaha's have that rough part on the frame that I will need extreme help making it smooth like the other part of the frame. So if some one has polished a Yamaha's frame before could you give me that information and don't leave out a thing especially that rough part of the frame.

Thank You.

Victor S [last name deleted for privacy by editor]
hobbyist motorcycle - Raleigh, North Carolina, United States

The frame on my Yamaha R6 was polished about 3 years ago and although I am constantly polishing it with shimmy chrome or mothers, I still can't seem to get it to shine as it used to, I have heard from other people that you can re-sand the frame to give it more shine or you can use Tripoli as well but I'm not familiar with either procedure and can't seem to find anybody who is, can you provide any assistance.

Your help will be greatly appreciated in the situation, thanks

Mario Z [last name deleted for privacy by editor]
hobbyist - West New York, New Jersey, USA

First of all, Anodizing is the second hardest substance known to man. You can sand on it for hours and not make a dent. Anodizing is VERY vulnerable to acid. Simple oven cleaner has a high enough acid content to remove anodizing.

It works fast, so be careful not to get any on aluminum parts you do not plan on polishing. Mask off with masking tape and plastic which ever parts you DO NOT want the anodizing removed from. DO NOT spray the oven cleaner, it is too hard to control. Use a cup, spray the oven cleaner into the cup, and then brush it on in heavy coats. You will see the anodizing bubble up, then, just simply wash it off of the frame, This will save you days of sanding time.

NOTE: your frame will look VERY bad when the anodizing comes off, it is normal, don't freak out and think you ruined it. Once you start sanding it cleans up very fast.

If you plan on doing the "Mat finish" part of your frame, you will need to start with a very rough paper. On the smooth parts of the fame, you can start with about a 300 grit, move to a 400 grit..then 600, 1000, ..

If you have a 1/4 sheet palm sander it will greatly reduce sanding time.

You will know when you have sanding enough for each grade, when you get through the 2000 grade paper, the aluminum will be like glass. You will need at least two VERTICAL buffing pads. and a small hand held grinder ( the pads are 4 inch pads, the type made of strings tied together) You will need bars of brown Tripoli, and bars of red Rouge.

Start with the brown Tripoli, turn the grinder on, with the buffing pad on it, and run it across the bar. go WITH the grain of the aluminum and polish until it shines. When you have a pretty good shine, thoroughly clean the aluminum with a cleaner made for it. Switch pads and repeat using the red rouge. Recently I have started using a white jewelers rouge, it colors a little better.

Don't cheat on the sanding, be thorough. Or else the result will be what looks like a shiny and dull finish...you will see spots not sanded well enough when you start polishing.

Also, ONLY remove the anodizing and polish the aluminum you can see, this way you can keep wax on it. Unprotected aluminum will oxidize. Hope this helps. Steve C [last name deleted for privacy by editor] - Walton, KY
Tripoli -	Rouge -	White rouge -

Thanks for the great response, Steve. Two minor notes: Anodizing is an extremely hard surface but it's not the 2nd hardest substance known; and oven cleaner is not actually acid, it's alkali, the opposite of acid.

Ted Mooney, P.E.  finishing.com Brick, New Jersey

 

The one thing I disagree with you on is the sanding direction. You HAVE to go AT A RIGHT ANGLE to the last direction you sanded, rather than WITH the direction in order to get a true mirror polish. Also, keep your buffing wheels separate from one another (change wheels each time you change compounds and keep them clean, PLUS water-rinse your part well between compounds). I just polished my rims and I used 220, 320, 400, 800, 1000 grit and then Tripoli rouge on a spiral sewn wheel, then white rouge on a loose buffing wheel... They GLEAM like CHROME with no pitting at all. But the key is go up-down with the 220 grit, then left-right with the 320, then up-down with the 400, etc. each time going until the previous grits' scratches are gone. It takes a ton of patience, but it is worth the effort.

Martin C [last name deleted for privacy by editor]
- Ft. Lauderdale, FL, USA

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Ed. note: Additional interesting letters on polishing of aluminum frames and rims include letter no. 800 and 1831.

Yes I am also wondering what is the best protection for a newly polished frame (Yamaha R6 1999) as well as what maintenance practices should b taken to ensure the best shine and protection of my newly polished frame?

Michael G [last name deleted for privacy by editor]
bike owner - Kansas City, MO

I.have restored two bikes,a 1957 BSA Gold Star and a 1972 CB750 Honda,on both engines I have polished the aluminium parts to MIRROR like finish using the 360/600/1200/1500 wetodry sand paper and then buffing with various size/shape rag wheels using MET-ALL aluminium polish.The first can I bought about 30 years ago,used it all (2 lbs),just last week I bought another can (1 lb) as I don't think I'll live long enough to use another 2 pounds,cost me 9.00 U.S., most pilot shops stock it at local airdromes..........and its made in the USA.,good luck

Ed.C.Weyn
- Waterford, Mich.

I have a pair of rocker panel moldings that I have to restore because the reproductions are just plain junk as far as quality goes and the NOS replacements are very expensive!
I have begun the process by using oven cleaner to remove the Anodizing and now I am ready to begin the sanding process to remove scratches. They need to be sanded and polished to a chrome shine finish and I need some input on this. I will protect the shine by using POR 15 shimmer as a sealer. Thanks, Sal.

Sal Rubino
Hobbyist - Fraser, Michigan

I did my bike frame. I used a 3M Green Non abrasive stripping wheel. It will not gouge into the metal. Once the paint was gone. I broke out the sander to knock off the cast look. I went through this process:
80 Grit
120 Grit
220 Grit
240 Grit
320 Grit
400 Grit
600 Grit
1000 Grit
1500 Grit
2000 Grit
Finish sanding with 3000 grit trizak pads
Broke out my baldor bench mount buffer and muscled it around the bike holding it in my hands
I finished buffing it using white compound
I roughed it in useing brown.
I worked it like a prom date using green
As I said above, finished it with white.
After I was done, I was asked who chromed my frame, Job well done..

Justin "T-Bone" Horodeck
- Hanover Park, IL

Did anyone of you use any type of clear when finished sanding and polishing?

Chris Herrick
- Greensboro, NC, USA`

NEVER POWDER COAT ALUMINUM! Any temp over 300 degrees can warp your part! Also, DO NOT USE A CHEMICAL TO REMOVE PAINT. It hardens the aluminum and you will not be able to get the shine you want.

Josh P.
- Nwa, AR

March 13, 2008 Thanks, Josh. I imagine that powder coating temperatures can distort some aluminum articles sometimes, so the warning may be helpful; but there are literally square miles of powder coated aluminum roofs and architectural features out there, and tens thousands of different parts and components made of powder coated aluminum. Some strippers are probably bad for aluminum but Aircraft Stripper [link is to product info at Amazon] is used on aluminum aircraft skins, so it won't hurt aluminum. Ted Mooney, P.E.  finishing.com Brick, New Jersey August 26, 2008 You can get a good result on non-cast parts of aluminum frames by using aircraft paint stripper to get paint and/or cleaar coat off first. Then start with medium or #0 Steel Wool [link is to product info at Rockler] steel wool for first cut. Then go to #00 or #000 fine steel wool for second cut. I call them cuts because you can feel the wool slide for a bit then it starts to bite. The bite is what you want to feel when using the wool. Pay attention to what you feel. If you feel slick or slippery parts, they need more work. This applies to both cuts with steel wool. When uniform "wooling" is complete, get a pair of latex gloves and some aluminum polish. I recommend mothers or qater (if you can find it). Rub the polish on small areas with old t-shirt or thick paper towel. I find going the same direction works best but,isn't always posible. Polish until the area is "black". Then take clean rag/t-shirt and rub til the black is holy cow I did that myself shiny. This way saves a lot of sand paper and dust. The cast parts of the frame will take more time. I suggest a brass wire wheel to smooth out the casting marks. You will have to take those scratches out with an extra cut with courser steel wool. Hope this helps. Aaron Lach - RSM CA. U,S,A,