Polishing/cutting aluminum to remove scratches

[Captainobvious]

I was hoping you all could point me in the right direction. I'm working on a couple of aluminum pieces which I've used the cross-sanding technique from 320 grit (it was pretty deeply marred) up to 2000 grit wet-sanding. I'm still left with scratches though from the sanding steps which are easily visible and I need to find the most effective way of doing a cut on the pieces to remove these scratches so I can finish with a highly polished finish.



Started like this:




Got the two pieces looking much better, but they still show scratches like this:






I have a rotary buffer (7") and a DA polisher (6"). I see some Blackfire pads and polishes available here on the site but wasn't sure if they were the right item for the job.

Pads
(Level one): BLACKFIRE Level 1 Pre-polishing Wool Pad, compounding pad
(Level two): BLACKFIRE Level 2 Metal Polishing Wool Pad


Polishes
Heavy Cut Compound: BLACKFIRE Heavy Cut Aluminum Compound, metal polish
Fine Cut Compound: BLACKFIRE Fine Cut Aluminum Polish, metal polish, wheel polish

Finally, is this (below) finishing polish basically a similar paste to the Mothers Aluminum wheel polish? I have a bunch of that but don't want to buy more of the same type product if not needed.
: BLACKFIRE Wet Diamond Aluminum Show Polish, metal polish


Thanks you for any assistance you can offer. This is my first attempt at doing any real metal polishing.

 

[Vegas Transplant]

... I've used the cross-sanding technique from 320 grit (it was pretty deeply marred) up to 2000 grit wet-sanding. I'm still left with scratches though from the sanding steps which are easily visible and I need to find the most effective way of doing a cut on the pieces to remove these scratches so I can finish with a highly polished finish.








Got the two pieces looking much better, but they still show scratches like this:

[

[


I have a rotary buffer (7") and a DA polisher (6"). I see some Blackfire pads and polishes available here on the site but wasn't sure if they were the right item for the job.

Pads
(Level one): BLACKFIRE Level 1 Pre-polishing Wool Pad, compounding pad
(Level two): BLACKFIRE Level 2 Metal Polishing Wool Pad


Polishes
Heavy Cut Compound: BLACKFIRE Heavy Cut Aluminum Compound, metal polish
Fine Cut Compound: BLACKFIRE Fine Cut Aluminum Polish, metal polish, wheel polish

Finally, is this (below) finishing polish basically a similar paste to the Mothers Aluminum wheel polish? I have a bunch of that but don't want to buy more of the same type product if not needed.
: BLACKFIRE Wet Diamond Aluminum Show Polish, metal polish


Thanks you for any assistance you can offer. This is my first attempt at doing any real metal polishing.

Save yourself from a headache and less than perfect results by going back to sanding once again.
Bite a little deeper this time.
Nothing more irritating than shiny scratches.

 

[Captainobvious]

Save yourself from a headache and less than perfect results by going back to sanding once again.
Bite a little deeper this time.
Nothing more irritating than shiny scratches.

Deeper? I started with 320 though...? The scratches that are visible are really from 1500-2000 grit papers. Should that be MUCH easier removable with machine polishing at this point? It's going to need to be polished anyway even if I were to go back with those grits again as you still have to remove those finer level scratches.

If it were paint, it'd be done and looking great already, but aluminum is a whole different animal. Frustrating to say the least.

 

[Captainobvious]

I stopped at a metal polishing shop and their tech told me I wouldn't get it any better than where it's at due to it being a large flat panel. He said I'd have some visible scratches from whatever surface was being used to polish it.

Well, I got it looking much better now. I used the DA polisher with an orange hexlogic pad (all I had for cutting) along with some mothers aluminum polish. Then followed up with a white pad and some M205 just to take the haze away from the previous step. Much, much better now. Not perfect, but definitely a big improvement.

It was very reflective, but had very visible scratches, more or less depending on the light and angle.








To show progress-
Before:




After:






Before:




After:

 

[Andy B. Cool]

I do a lot of metal polishing and what I think happened is you didn't need to do a cross hatch sanding for one and you didn't fully remove the lower grade sand scratches as you progressed up. What I do is usually by machine with an interface pad always and inspect before moving on. After getting up to 2000 you can use a microfiber cutting disc and your favorite metal polish follow by a foam pad and favorite polish.

 

[Captainobvious]

I do a lot of metal polishing and what I think happened is you didn't need to do a cross hatch sanding for one and you didn't fully remove the lower grade sand scratches as you progressed up. What I do is usually by machine with an interface pad always and inspect before moving on. After getting up to 2000 you can use a microfiber cutting disc and your favorite metal polish follow by a foam pad and favorite polish.

Thank for chiming in :xyxthumbs:

Yeah, I think I got a little sloppy once I was at 1000+ grit when wet sanding. Sometimes it's tough to tell if you've gotten all of the cross sanding marks out unless you're at the right angle to see them. Yeah the MF pad would probably work better as well. I'm new to this, so I was just happy to get the result I did. I probably put in way more work and time than was necessary, but at least I ended up with a result I can be happy with.

Thanks!

 

[g35_coupe]

We polish nacelle nose caps and the Falcon 900 jets are aluminum (not stainless). We use a purple wool cutting pad with Mother's aluminum polish after some 800/1500/2000 wetsanding. You can usually get a slightly better shine if you go over it by hand (hand polish) afterwards with a clean cloth. Looks great after your second round!

 

[Captainobvious]

We polish nacelle nose caps and the Falcon 900 jets are aluminum (not stainless). We use a purple wool cutting pad with Mother's aluminum polish after some 800/1500/2000 wetsanding. You can usually get a slightly better shine if you go over it by hand (hand polish) afterwards with a clean cloth. Looks great after your second round!

Thanks for the encouragement Yeah, it's highly mirror like now with only some minor imperfections, but it's great for what I was going for.