Polishing Aluminium Need Help

[gtr0321994]

hey guys just need advice on how to polish cam cover plus valley covers i have paint stripped it wet and dry from 400,600,800,1000,1500,2000,2500 and 3000 and then used autosol but it looks pretty dull haven't got mirror finish any help would be nice cheers joe

[Shoota_77]

You need power for the next level of shine. Get a die grinder and you can then buy el cheapo polishing kits from Supercheap that you can put in the die grinder check and polish the life out of it. The kits even come with different polishing compounds to match the different polishing pads to go through the different levels of shine.

[ARTZ]

Bugger the Die grinder you will be there for weeks... bunnings have small polishing kits in the toil section...I'd recommend just getting buffing wheels foe your drill there is a 2 wheel kit, one is course and one is a finishing buff...try to get one that doesn thave a huge bolt through the middle as these tend to scratch easily and fall apart..Also the paste style polishing kits are horrible to work with, (I think the brand is Joscal iirc )instead go to Autobahn...look for a product called Purple...use this with the buffing wheel on your drill, It will come up pretty good.

[gtr0321994]

Cheers guys

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[D.I.Y. Mik]

Josco is what your thinking of.

I find its the most powerful

You can polish too much if your not careful, then its not flat anymore and looks like chrome plastic.

oops

Oh.. and a clearcoat, never polish again.

Edited March 15, 2014 by D.I.Y. Mik

[gtr0321994]

Ok boys used the buffer with the white compound still comes up with a cloudy haze not a mirror finish

Edited March 16, 2014 by gtr0321994

[D.I.Y. Mik]

Try the coarse one, then fine.

Takes some time and effort, buff untill the haze is gone.

and clean off residue

[GOD12A]

Hey guys,

My DIY suggestion would be to go down to 400, maybe 600, grit then use a bench grinder with pigtail on it so you can spin on a stitched buffing wheel and go nuts with a grey or red/brown compound till you get an even shiny finish everywhere.

Clean that down with a few clean rags and kero/WD40/metho/petrol.

Go again with a loose mop buffing wheel and white compound for a nice finish. Don't get the aluminium too hot (keep moving the work piece) otherwise the white will streak. Streaks can be easily remove with kero, just wipe them off and go again.

I suggest wearing gloves to stop your hands from burning from the heat and ALWAYS wear safety glasses. A dust mask is suggested.

If I can help further, lemme know. I spent a few years running my own metal polishing business and worked on a few show winners here and there.

Mark

[gtr0321994]

Thanks mate how do u get in the tight area

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[GOD12A]

Heya GTR,

I used a Dremel tool and made my own polishing bits.

To DIY, you can use some balsa wood (soft craft wood) and some 400/600 grit wrapped around it to polish the tight stuff, then you can squeeze a small buffer in there, or go at it with some Autosol polishing paste on a rag wrapped around a balsa wood stick. It really depends how far you want to go.

Here's a 12a twin dizzy timing cover for a well known RX3 I did a while back:

And a gearbox for the 2005 Summernats Grand Champion:

Both had some intricate work to get in the tight corners.

I've done shedloads of 20B and 13B REW intake plenums and polished between the lettering to make it look nice, it just takes time and an eye for detail.

Mark

[gtr0321994]

mark that looks bloody awesome thanks for all ur tips if i have any more problem i know who im calling

can i also use brown compound white then red or brown white then green compound

Edited March 17, 2014 by gtr0321994

[GOD12A]

Thanks GTR,

The colours are similar across most brands.

GENERALLY you go from darker to lighter colours. The lighter the colour, the finer the compound. There's exceptions to this, but as a DIY rule of thumb, it'll get you over the line

The JOSCO kits from Bunnings etc work ok for the DIY'er.

Just remember, hardest to softest, darkest to lightest and NEVER mix compounds. So your sewn mop (hard buff) should be used to grey/brown/red compound and your loose mop (calico/soft) should only be used with the white/blue compound.

Kerosene is the best cutting compound for aluminium, it's also great to clean the left over compound off your job.

Many people like to polish down to 2000+ grit. This isn't necessary if you intend to hit the part with a sewn/hard buff. The compound will glide over the top of the fine 2000 grit scratches and won;t do much. The compound needs something to bite into to work, so 400-600 grit should be fine with a bit of extra time on the buff.

With my hardcore setup, I'd never go finer than 400 grit and sometimes I'd even bypass the roughing stage all together and hit the buff straight from cast (obviously a little further advanced mop and compound selection with a 1kw buffing motor).

Any questions, just ask away.

Mark

[gtr0321994]

cheers mark again awesome just learnt so much right there spending hours sanding for nothing lol saved me hard work and pain

Edited March 17, 2014 by gtr0321994

[GOD12A]

Oh yeah, I suggest dipping the emery paper in a cutting compound regularly so the paper doesn't become loaded up with swarf. It'll work faster and look better as well as using less emery paper for the same job.

As mentioned, kero is the best cutting compound, but water will work OK.

When moving to a finer grit, change the direction of polishing by 90deg. If you keep polishing in the same direction when you move to a finer grit, it'll take longer and the result is not as good (you're polishing along the previous grooves/valleys, you want to cut across them)

Mark

[gtr0321994]

sweet as mark

[D.I.Y. Mik]

Love it when a pro gives us his hard earned knowledge.

Those bits look amazing, now i want to polish everything.

Thanks Mark

SAU is great for this stuff.

Hey Mark, what do you think of clearcoating it?

Does it last? It seems to look ok on the bits ive done.

[GOD12A]

Heya DIY

Polishing everything sucks.

I polished everything in my RX3 enginebay back in the day and I hated hand polishing it every few weekends and I did it full time! Each to their own

There's no clear coat on the planet I was happy to use.

Every one of them will either wreck the finish (introduce orange peel or dull) or not stick to the highly polished surface.

The most obvious choices are:

Powder coat. Is too thick (dulls and orange peel)

2K paint. Won't stick and will brown with engine heat.

Best to hand polish it every few weekends with Mothers or Meguiars polish. Autosol works great for chrome and stainless but it's too course for perfectly polished aluminium (although great to remove water marks and light corrosion).

Mark