DIY: Minor repairs to mag wheels...

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How to: Minor repairs to mag wheels

Thought I’d start a thread on how I went about repairing the gutter rash on my VY SS rims. These rims are similar to GTO rims you have there. All 5 of my rims were rashed from the previous owner. I really liked the finish on a set of powder coated wheels I saw on a mate’s car so this is the path I’m heading down as illustrated in this thread.

This is cosmetic damage only. I would recommend getting any structural wheel damage repaired by a competent wheel repairer.

Firstly, remove the affected wheel(s) from the car and take to a recommended tyre fitter to have the tyres removed. This should cost about $7 - $10 per wheel. I lined up a set of borrowed wheels (thanx Mark) that would fit over my brakes and keep the car on the road while my rims were being repaired.




Once the tyres are removed, clean the rim and inspect closely for cracks. Unfortunately one of my rims had a few cracks. Consider getting it repaired or discard and buy a replacement rim like I did.




The aftermath of brail parking…





You will need to strip the rims of centre caps, weights and valves. VY SS centre caps have a spring ring on the back that is easily removed with point-nosed pliers. Then just pop them out from the back to the outside of the rim.

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Weights clamped to the inner edge of the rim should come off with some persuasion from a set of pliers.



Internal stick on weights can be carefully prised off with a bladed screwdriver. If you are worried about gouging the rim, wrap the end of the screwdriver with a little electrical tape, but if you are careful you will have no trouble. Be sure to remove any sticky rubber left on the wheel, as sand blasting generally won’t remove it.



My wheels had rubber valves. To remove these, use a sharp knife to cut through the inside of the valve as shown in the picture below.




Any tool shop can set you up with a Dremel style tool for this job; it will make life far easier.



Using an 80 grade flapper wheel, smooth back the sharp and gouged alloy. Do this slowly and progressively so you don’t wear too much metal away in one spot. Only take off any protruded metal.

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At this point the rims are ready to be blasted. I used Kyzac Coatings at Tomago near Newcastle. I organised with the boss to have the rims blasted and then take them back home for repair. Once blasted and back home it’s time to fill the nicks and scratches. Do not handle the rims with bare hands; use a clean cloth or latex gloves to ensure minimal impurities such as oil from your skin makes contact with the clean metal surface. Ensure you have a clean area with plenty of access to repair the rims.

The rash is harder to see after blasting so you may need to block sand the surface lightly with emery cloth to reveal the low spots.

As powder coating requires the product to be baked in the final stages, you will need to use metal filler that can withstand some level of heat. ‘Devcon’ is a good product and should be considered if you can get it. I went with ‘Quick Steel’ by ‘Dyna grip’ on the advice of the shop assistant. I warned him I’d be back with the remaining putty if I was less than happy with the product. No need though, it is very good to work with and cures extremely hard, ready to sand in 1 hour.



‘Quick Steel’ is a two part epoxy that is formed together in a tube. Cut the required amount off, making sure you have slightly more than you need for say 1-2 rims depending on level of damage. Don’t get ambitious and mix so much that it starts to cure before you finish filling. Kneed between your fingers (using gloves) until the putty is a uniform colour. It should get hot to touch while mixing.




Press the putty (or use a flat tool if using ‘Devcon’) into the nicks and scratches immediately after mixing, ensuring no air pockets exist between the putty and rim surface.




Once fully cured (in my case an hour, ‘Devcon’ requires overnight from memory) use 180 grit paper on an orbital sander to sand back the putty. Use a flat smooth motion and follow the profile of the wheel. Sand back until the putty is just flat with the surface. This will take practice so be patient. Dust excess putty away with a clean cloth.

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Once you are happy with the result, return the rims to the powder coaters for coating. Kyzacs said they will give the rims another light blast to remove any oils that may have made it onto the surface, but not enough to blast the putty out.

I went with a colour called ‘Nepean Silver’ which is slightly darker than the original colour and has a heavier metal flake through it. I also had a clear coat applied as well. It really made the wheels glossy and made the metal flake more obvious.

Rims after final coat…





Back to the tyre fitters to have the tyres put back on, new valves, and balanced. Return freshened up wheels to car with centre caps. As per usual, open beer and stand back and admire…




Cost summery (for 5 rims excluding tools) :

Tire removal $50

Metal putty - $15

Sheet of sand paper - $1.50

Rim blasting/coating - $250

Tire fitting/balancing - $60

Carton of beer - $38

Total for 5 rims: $414.50AUD ($376AUD if you don’t drink )

Hope this helps anyone thinking about tidying up their old rims…