Metal Polishing

[lordaus92]

Hi all,

I have noticed that a few members on this Forum are into Polishing Metals. I am currently looking to get started into trait and am looking for some direction.

At current I am looking to purchase the large kit from CaswellPlating for $150.

Handheld Drill Buffing Kit

My first question is, what do you guys use, Drill, Grinder or Bench Grinder ?
At the current moment, I am looking at trying my hand at some smaller pieces, then moving to rocker covers etc. Also, I won't really be dealing with nickel or stainless.

Here is my current understanding of the process; [Trying to Obtain Mirror Finish]

Strip, Wash and degrease the part. Allowing to dry.
Wipe the part down with Thinners.

ALL WET SANDING BELOW
Sand the part Lightly with 120 grit.
Sand the part again with 240 grit in the opposite direction.
Sand the part again with 400 grit in the opposite direction.
Sand the part again with 600 grit in the opposite direction.
Sand the part again with 1000 grit in the opposite direction.
Sand the part again with 1500 grit in the opposite direction.
Sand the part again with 2500 grit in the opposite direction.

Making sure the fully sand out the previous marks before moving to another grit.

Allow the metal to dry and wipe down with a Mircofibre Cloth.

Now this is where I get lost.
If I was doing 5 Litre Engine Covers, what wheel and compound would I use?
How many times do I apply the compound?
Then wipe the final product with Vienna Lime?

I am mainly concerned as to what machine to use and my method. Any links and personal experience would be great.

Thanks, Chris

[D3V14NT]

I'm currently polishing the intake manifold off a VP V6.

I've used sanding disc's and drums on a die grinder to remove the casting marks and to initially sand the surface down as the intake manifolds are very pitted and to sand it all down by hand would be a nightmare. Have to be careful when sanding with a power tool as you can very quickly put dips and grooves into the surface, which will stick out like dogs balls when it's polished.

Once thats done I've gone over it with 120 grit emery. The sanding drums in particular leave very deep scratches (still better than the pits though) which take quite some time to sand off with the 120. After the 120 grit I give it a clean and move on to 240 grit emery. After that clean it again. Then I start using the wet and dry. I personally go from 400 to 800 to 1200 cleaning between each one.

After that I use the sisal wheel with a grey (cutting?) compound I have (got mine from bunnings if that helps). Degrease and clean and then use a cloth wheel with a white (polishing?) compound. I use smaller wheels (4" i think) with a drill bit adaptor on a drill (obviously) as well as very small wheels on the die grinder for those tight spots.

You apply a small amount of compound to your wheel to give it a light coating and then use the wheel until it the applied compound is used up then reapply, etc. Never use two types of compound on the same wheel and always degrease and clean before moving on to the next compound.

I tried this all out quickly on the thermostat housing and got a nice mirror finish (no pics sorry) am now doing the intake manifold and is definitely much slower as the initial surface is terrible and takes a long time to sand back nicely.

Be prepared to spend a lot of time sanding.

[lordaus92]

How about this for polishing and buffing?

BENCH GRINDER 10" GRINDING MACHINE INDUSTRIAL NEW (eBay item 400144139876 end time 12-Dec-10 17:08:18 AEDST) : Industrial

[D3V14NT]

Will definitely do the job, you'll probably need to remove the guards to get bulkier objects in there though. You can also get bench polishers which are pretty much the same thing but with longer shafts to the wheels, again so you can get bulkier objects onto the wheels.