DIY: fixing scratches in polished metals

[CThunder-blue]

I had to fix some gouges in my Yoshi exhaust heat shield, so I figured I'd do a DIY. It doesn't take much time and is pretty easy. The cost of tools may outweigh the cost of the job if you only need one or two pieces fixed. That being said...

What you will need:

Electric or Pneumatic Sander
60-220 grit sand paper
6" Bench polisher
Various polishing pads
Microfiber cloth
Polishing compounds: Black, Brown (aka Tripoli), and White. White is only for aluminum. I found that the brown was more than sufficient for Stainless Steel. Following the brown with green didn't make a noticeable difference, so I wouldn't waste my time with it.

You may not want to wear nice clothing for this because it will get messy and dirty fast.

So, here's what I have: I picked up the polisher from harbor freight for $45. The compounds were around $3 each from HF as well. The different wheels were about $5 each.







Here's my project to be worked on:



You can see it's got some deep gouges.

[CThunder-blue]

Step 1: Flatten the scratches so you have a nice even surface. You may want to start at a medium grit to see how it does on the scratches. It will depend on how deep they are. I started with 80, but moved down to 60 because the 80 just wasn't doing it. When you sand, don't put pressure on the sander. Just let the sand paper do it's job. All you need to do is keep it from walking onto the areas you don't need to refinish.

Here's what I got with the 80:



You can see there are 3-4 deeper ones still present. Slapped on the 60 and went over it again.



Last pass with the 220 to smooth out the large scratches from the 60.

[CThunder-blue]

Step 2: Here's the fun part. Install the flap wheels to the polisher if you haven't already done so. The fully threaded wheel is for the black compound. The half threaded wheel or unthreaded wheel will be for the brown. The brown can be used on a fully threaded wheel, but don't use the same one that got used with the black. Always keep your compound wheels separate.

To add the compound to the wheel, start up the polisher and touch the compound to the wheel. It should begin to melt the compound and the wheel will take on it's color. You don't need to coat the wheel entirely, just 1/4 of it will work.

The sequence of compounds is: Black, Brown, and (green or white if necessary)



Step 3: Now that your wheel is coated with the black compound, pick up the project and hold it gently but firmly against the wheel. You shouldn't need to put too much pressure against the wheel, especially one that's fully threaded. Just run it along the bottom if you can.



After a few minutes, the compound should have removed most of the scratches. If more compound is needed, just add more.

This is after 1-2 minutes with the black:

[CThunder-blue]

As you can see, the black did it's job and removed all the fine scratches after a few more minutes:



Step 4: Now add the brown or tripoli to the other wheel. The wheels from HF aren't that great and began to grow hairs when the wheels caught some speed. I just trimmed the hairs off to have a nice even wheel.





So, repeat Step 3 and run the piece on the brown wheel.

After a few minutes, you will have a refinished piece that looks as good as new

Step 5: Just take that microfiber cloth and buff off the compound.

Check out the reflections!







You can't tell where the factory polish begins and where my refinish ends

I hope this helps!

-Tri

[kkim]

Thanks! Always wanted a step by step on how it's done.

What attachments can you recommend when you can't take the parts to the polishing wheels? I have some engine parts and wheels that could use some polishing but will be still mounted on the bike while working on them.

[Racer x]

Nice job. I love polishing metal.

[HKr1]

Originally Posted by kkim

What attachments can you recommend when you can't take the parts to the polishing wheels?

Die grinder with small polishing wheel works really nice. Drill with same wheel, not so nice........

[JMcDonald]

Originally Posted by Racer x

Nice job. I love polishing metal.

Haha. Nice job indeed, but I, on the other hand, absolutely hate it. I got half way through polishing a set of 2-piece wheels for my old MR2 before I just about lost my mind and painted them :P .

[CThunder-blue]

Originally Posted by HKr1

Die grinder with small polishing wheel works really nice. Drill with same wheel, not so nice........

Yep. Drills don't spin fast enough to get a good shine on metal. I've used a drill on aluminum fuel rails and it turned out pretty nice, but it took hours.

This HF kit comes with the attachments you would want to use on wheels or hard to reach places:

http://www.harborfreight.com/14-piec...kit-98707.html

Here's a Die Grinder:

http://www.harborfreight.com/air-too...der-95029.html

Just make sure the shank on the attachments fits the collet on the grinder. You will also need a compressor capable of maintaining 5 CFM for this particular grinder.

[kevlarorc]

Bah. That'll buff o-

damnit.


If I had loads of money I would have a big garage with loads and loads of tools like that buffer all over the place so I could learn to do all this stuff.

[kkim]

Originally Posted by HKr1

Die grinder with small polishing wheel works really nice. Drill with same wheel, not so nice........

Originally Posted by CThunder-blue

Yep. Drills don't spin fast enough to get a good shine on metal. I've used a drill on aluminum fuel rails and it turned out pretty nice, but it took hours.

This HF kit comes with the attachments you would want to use on wheels or hard to reach places:

http://www.harborfreight.com/14-piec...kit-98707.html

Here's a Die Grinder:

http://www.harborfreight.com/air-too...der-95029.html

Just make sure the shank on the attachments fits the collet on the grinder. You will also need a compressor capable of maintaining 5 CFM for this particular grinder.

Thanks!

[Cuongism]

I have polished wheels that are looking really dirty. What compound would you recommend using with a dremel (I have a rotary tool but too large for polished wheels). Dremel is good for anywhere from 10000-25000 rpm so which end of the spectrum is better? Thanks!

[CThunder-blue]

Originally Posted by Cuongism

I have polished wheels that are looking really dirty. What compound would you recommend using with a dremel (I have a rotary tool but too large for polished wheels). Dremel is good for anywhere from 10000-25000 rpm so which end of the spectrum is better? Thanks!

A dremel will take you a very long time because those attachments are extremely small. The type of metal will determine what compound you will want to use. If it's aluminum, you will want to use White. Use a low speed (maybe 12000) on the dremel and keep the wheel wet with compound.

If they're just dirty, I would suggest using a non-abrasive cleaner instead of trying to repolish them. Also, if they're clear coated, polishing won't do much. Mother's Mag polish works pretty well on a ball and drill attachment for cleaning. Just tape up the areas you don't want to get the polish on.

[Cuongism]

i stripped the paint on the wheels so they're bare metal. They're getting dull and my elbow grease isn't very effective so I was looking towards using some kind of tool.

[CThunder-blue]

Ah ok. If you have access to a die grinder, I would suggest using that along with the steps above to get a mirror finish. I'm not sure, but if the wheels are AL, then go black, brown, then white. The same would be with the dremel. Just be very careful not to let the wheel on the dremel get dry. Keep it wet with the compound and you should be fine. be prepared for many hours for each wheel tho.

After they're polished, I'd suggest spraying some Dupli-color high temp clear coat on them. It'll help protect the shine. Either that or get them powdercoated.

[Alex]

/linked to DIY sticky thread.