How to polish mag wheels

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woops
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Re: How to polish mag wheels

Post by woops »

When i polished up mine i used about 120 to start to take out the machining grooves and the went in stages from there to 240, 400, 800, 1200 and then onto 2000. I made sure that each step i took i changed the sanding direction. It makes it easier to tell when you have sanded enough as the next step will take out the scratches from the previous step. For example one way i would go circular around the rim and then the next step I'd radiate out from the centre. The final step i used megulars aluminium polish with some terry cloth and they came up to a perfect mirror finish. I must admit that i also used a random orbital sander for the 240 and 800 steps which saved a little hassle. The pads above 240 you can only get from specialist stores like paint stores. Don't bother getting those Velcro sanding pads from bunnings as they really rip you off for price. The paint shop sell 50 packs for like 40 bucks and bunning you get a 4 pack for 10 bucks.

Personally i wouldn't do it again but it does give you a satisfaction to know that you did that. Especially after finding a guy who did a mates set of alloys for a navara or something that for $40 a rim. He apparently has a rotating table and setup designed for wheel polishing especially.

Oh yeah also you can get a clear coat paint especially for polished aluminium but i think it was something like 150 bucks for half a litre. Otherwise you just need to keep the rims clean and polish them back up with the megulars aluminium polish. No need to go to the sanding steps unless they have started to corrode. Just make sure when you do re polish them that the rims are perfectly clean and the cloth is completely clean of any dirt particles as these will definitely scratch your rims. I have had a problem of some of the centre caps corroding when the rims are still shiny. Maybe the centre caps are made of a poorer quality alloy. I know i got one of the centre caps from one of the really an ugly SE dinner plate style alloys but i don't know if that is the one corroding.
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75wagon
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Re: How to polish mag wheels

Post by 75wagon »

ddt wrote:the turbo rims and pepperpots have fine grooves on the surface- are these completely polished out to get them that shiny?
If you want the rims smooth and clean looking, then yes. They will still polish up with the machining marks in them, but you will still see them when they are polished.
I have made a sanding jig, that I fit the wheel to and it is spun slowly by an electric motor. That means that all I have to do is hold the sandpaper in the one place while the motor does the work for me. It takes me about 10 to 20mins a wheel for the sanding part. I have trial and errored a lot of methods and found this one to be the best. If you don't have or can't build a jig, Woops' method is probably the way to go.

When I get a set of wheels I sand blast them first. This removes old paint (if any) and helps rough up the machining marks and makes sanding faster. The hardest part of sanding seems to be getting past the machining marks in the first place.

Polishing is actually really easy if the wheels are sanded thoroughly enough. All the work is in the sanding not the polishing. The worst part is when you polish the rims up and the sanding isn't good enough, so you have to sand them again and start polishing them all over again.

Then the painting of the slots and holes. I have found brushing Enamel the most successful. It took me 4 hours to hand paint a set of 4 rims with 2 coats using black signwriting enamel. But took me 5 hours to mask up a set just to spray. I also found acrylic lacquer unsuccessful. It didn't stick, I did not use and etch primer :$ , I know now that is what I should have done (with enamel you don't need to).
ddt wrote:Also what kind of clear-coat or wax have people tried on their rims?
The polish I have used is the metal polishing bars (like cakes of soap) that are used with polishing wheels. They leave a waxy coating on the rim and still look good after 6 months of being out in the weather. They are easy to bring the shine back up with as well.

I haven't used the Meguiars aluminium polish, but I assume it it like Autosol. Autosol is a fine cutting paste that works exactly the same method as cut back polish for car paint. After using the cotton polishing wheels and the bars of polish I would never go back. The negatives of that method is, it is messy and noisy. You end up wearing a layer of aluminium and polish. You also wear a layer of the polishing wheel as it wears down. I wear a pair of disposable overalls and a arc welding mask (with the darkened visor up obviously). And I recommend a set of ear plugs or muffs.

Like anything, it comes down to how much money you want to spend. The wheels and bars of polish are I think superior, but the cost is rather large by comparison to a single tube of metal polish by Meguiars or Autosol. Mind you, the more I hear about polishing shops that will do rims for prices like $40 a rim, then why would you bother doing them yourself? I know there are countless hours of my life I will never get back. If I would have known that you could get it done for that price guess what I would have done? But I a still yet to know anyone who has actually got a set done for anything like that price?

If you rims are heavily corroded and have deep pits. Don't bother polishing them. They will look like rubbish when you are done. All you can do if they are heavily corroded and have deep pits, and you really want them polished is take them to a machining shop and get them refaced on a lathe. Or just buy another set that are good enough to polish.

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woops
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Re: How to polish mag wheels

Post by woops »

Actually i forgot to mention that yeah i also used a small sandblaster to clean up inside the holes of the pepper pots as it is just too hard to sand in there. Make sure you sand blast forst though as even the 120 grit is smoother then the sandblasting effect. Also you can use it to clean off the deteriorated clear coat from the rim surface but so does sanding and unless you have a sandblasting cabinet you will use a lot of sand doing so. I made an enclosed area out of some ply to try and reuse the sand again as much as possible.

I wouldn't mind actually seeing your jig that you used. Actually knowing me I would probably take longer to make the jig then it would have saved me in time as i have no welder or welding skills.
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ddt
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Re: How to polish mag wheels

Post by ddt »

good info there guys.
I did buy that josco metal polishing kit (with sisal wheel and buff) but was disappointed. However after reading your experiences; i should really save that step until the rim has been well sanded first.

Any one used any acids?
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75wagon
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Re: How to polish mag wheels

Post by 75wagon »

ddt wrote:I did buy that josco metal polishing kit (with sisal wheel and buff) but was disappointed. However after reading your experiences; i should really save that step until the rim has been well sanded first.
Nothing is ever easy, as I see you've found already. You still need to do the hard work first.
ddt wrote:Any one used any acids?
No, but I'd be curious to hear the result.
woops wrote:I wouldn't mind actually seeing your jig that you used. Actually knowing me I would probably take longer to make the jig then it would have saved me in time as i have no welder or welding skills.
I need a wheel to put on it to really show how it works. I will be doing another set soon, I'm just a bit snowed under with work atm...
I'll get the tyres taken off those rims soon, and show how I've done it.
It's very simple with no welding required, at all.
To build it, you need:
- 1 front strut with hub still attached
- 1 9 inch polisher sander with rubber sanding disc backing, rpm needs to be adjustable down to 500 rpm, a 9 inch grinder spins at 9000rpm minimum, at 9000rpm you would be taking your life into your own hands.
- 1 plank
- 2 timber chocks cut to suit
- 2 tie down straps
it's crude, but it works very well. I don't even need to use wheel nuts to hold the wheels on (they take your fingers out when you sand the centre of the wheel)
I will get some pics up soon.
BTW, a adjustable polisher/sander is about $400. So buying one just to drive a mag wheel sander probably isn't very smart, but I had one already. Someone might come up with something else they can use?

Dave...
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kenvv
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Re: How to polish mag wheels

Post by kenvv »

could you not jack up the rear end of the car and have someone give it a little throttle to spin wheels and you hold sandpaper there. then switch front wheels to back after and repeat. just a thought for a cheapo alternative to get a motorized rotisary going. just gotta be caerful of fingers
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75wagon
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Re: How to polish mag wheels

Post by 75wagon »

kenvv wrote:could you not jack up the rear end of the car and have someone give it a little throttle to spin wheels and you hold sandpaper there. then switch front wheels to back after and repeat. just a thought for a cheapo alternative to get a motorized rotisary going. just gotta be caerful of fingers
I've done it before.

The amount of sanding that needs to be done is better done at a comfortable height. But if I was only ever going to do one set, I'd do it that way for sure. For Turbo/Wherret rims having wheel nuts holding them on makes it very difficult to sand them while spinning, so you'd have to do the centres by hand. Pepperpots would be as easy as.

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ddt
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Re: How to polish mag wheels

Post by ddt »

i've got an old washing machine motor kicking around and i could borrow one of the big old Variac variable voltage transformers lying around at work to throttle the speed. :think: i might try do something with that.
I've got a set of pepperpots to do as well after i'm done with the turbos.
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webby
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Re: How to polish mag wheels

Post by webby »

It'd be piss easy with your pepperpots and turbo rims compared to my wheels. I've got a set of Hotwires here I need to sand back and respray somehow :(
At least the stock alloys will be easy :)
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75wagon
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Re: How to polish mag wheels

Post by 75wagon »

Hotwires aren't difficult.
Paint them first, then sand the alloy part of the wheels back and polish (painting them first means that you don't have to mask up the face of the alloy around all the holes).
Job done.
Granted it would be easier if the tyres and valves are not fitted to the rim.
The big thing you have in your favour, is that they are a smooth rim and don't have machining marks in the face of the alloy. That saves you at least an hour a rim to start.

Or easier still, just paint the faces of the spokes black with the holes and just polish the lip. They look tidy like that, it just depends what look you're after.

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Re: How to polish mag wheels

Post by 75wagon »

woops wrote:I wouldn't mind actually seeing your jig that you used. Actually knowing me I would probably take longer to make the jig then it would have saved me in time as i have no welder or welding skills.
Sorry it's been a long time coming, but here are the pics.
What you are looking at is:
- a Galant strut with the caliper removed
- Makita Polisher/Sander not a grinder. Grinders spin at 9000 rpm, the polisher sander spins at low speeds that are adjustable (500 to 3500 rpm from memory, I'll have to check to be precise)
- 2 blocks of wood with v cuts to locate
- 2 tie down straps.

By the time I'd taken these pics I had already started 3 wheels. The aluminium filings are from the removal of material from the outer edge of the rim to remove gutter rash.
Image

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In action
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Body file used to remove gutter rash
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file face used
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Obviously, after filing I use grades of sandpaper and wet and dry until a sooth finish is achieved. Then the Josco polishing kit is used.
The work is in the sanding. The polishing is almost no work at all after it's sanded back far enough.

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kenvv
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Re: How to polish mag wheels

Post by kenvv »

the black disc thats on the rotary sander, what is it? rubber? to give the grip to spin the tyre?

all in all its an awesome idea to save time. and cheap and (seemingly) easy to do, if you have a sander and willing to remove a strut. good work
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75wagon
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Re: How to polish mag wheels

Post by 75wagon »

kenvv wrote:the black disc thats on the rotary sander, what is it? rubber? to give the grip to spin the tyre?
It's the rubber backing used behind sanding discs.
I wouldn't use it on a rubber tyre, it leaves a definite line around the rim.
If you wanted to rub back a wheel with a tyre on it, I would suggest a wider surface to drive it by. I just used what i had lying around.
kenvv wrote:all in all its an awesome idea to save time. and cheap and (seemingly) easy to do, if you have a sander and willing to remove a strut. good work

I had a spare set of struts lying around (I've stripped a few Galants/Lancers over the years).
It works perfect for Pepperpots and Turbo/Wherrit wheels.

Here's a set I sanded/polished on this set up (same pic from earlier in this thread)
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kenvv
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Re: How to polish mag wheels

Post by kenvv »

i would definately have done it to my set. but ive decided to sell my turbo rims to buy some wheels with a better offset. if i get that bored i may polish them up for the sale but depends if can find and old strut around the place.
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Re: How to polish mag wheels

Post by GC75 »

moved to new area :thumpsup:
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Converted to the Ultimate Driving Machines
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