I’m having trouble getting a good mirror finish on these two aluminum bars pictured below. So far I’ve tried sanding them with 320 grit wet sandpaper and moved through various grits up to 2000 grit, then I finished thrm off with some cheap Mothers aluminum polish on a microfiber cloth.
For reference, each bar is approximately 1” x 10”
It looks good in a low light environment, but as soon as you shine a light on them you can see a million little swirls as seen below.
Any thoughts? I feel like I’ve missed a step along the way.
Sounds like you did the right process, going from 320 all the way to 2000. But how many steps in between? When moving from grit to grit, remember all of the material left on the surface from the previous “coarser” grit needs to come off. In other words, eventually you have to end up removing all of the material left behind after the first step, sanding down through the deepest “scratches” left by each previous step.
Depending on how the swirls look, maybe all you need to do is first polish with a coarser aluminum polish than the Mothers.
I’m no expert by any means but I’ve buffed out a few pieces with decent results. First and foremost, put any and all bright lights away when inspecting your work, especially cool white. Cool white seems to show every flaw no matter how minute. Sunlight is much better. You’re on the right track with sanding, but I’ve found 800 grit is about as high as you need to go. I usually stopped with 600. For me 3M wet/dry paper with some soapy water works best. To get the chrome look, you’ll need to get some cotton buffs and some black or brown and white buffing compound. Check out Caswell plating or Eastwood. Lots of good reading material on both sites as well as supplies. I hope this helps.
I would scrape with razor blades before sanding, and go straight to much finer grit (probably 600 wet, then 600 dry). Starting with course paper just creates more scratches than were there to begin with. Also you probably need a coarser backing for the jeweler's rouge before moving to the rouge on the soft cloth.
Also when buffing, alternate, don’t buff in the same direction, as it looks from the picture like your only polishing along the metal?
By going in one direction the light reflects more in one direction making the scratches more visible to the eyes
Use a power buffer of some sort—I’ve had good results with regular car coarse compound then fine compound—they also have special stuff to remove swirl marks—Of coarse if your scratches are too deep sand them out—try coarse first and see how you stand
Sometimes I think I must be the only person on the planet who knows what you can do to aluminum just by dragging a razor blade across it a few times... :_(
Thanks for the replies! I started from scratch again and tried some of the things you guys suggested (including the razor trick you mentioned comfy chair!), and it seemed to help quite a bit.
I worked on the bottom piece; the top bar hasn’t been touched yet.
I think I still need to practice a bit and maybe look into some better compounds or getting a proper buffer, but the results are quite presentable as-is. Thanks again for the help!
You need to step through each of the grit grades without missing any. Sand in one direction with grit 1 and then perpendicular to that grit 2. You have to ensure you do it thoroughly. What you have is because you’ve missed a grit. So by going from grit 1 size to grit 3, grit 3 isn’t course enough to remove the valleys left by grit 1. You’re also probably only going along the bar so at times the grit just slides into the valley and makes it deeper, as opposed to going across it and smoothing down the hills.
If you’ve got a motorised buffer then none of this matters because those things will take out those scratches with ease.
BS. It doesn't matter which grades you use as long as you remove all evidence of the previous one. You can go straight from 400 to 1200 and it will take forever but if you keep going until there's nothing remaining from the 400 grit stage, the end result will be exactly the same.
Scrape with razor, 600 grit wet on glass, jeweler's rouge on printer paper (also on glass), final polish with dry cotton cloth...
Scrape with razor, 600 grit wet on glass, jeweler's rouge on printer paper (also on glass), final polish with dry cotton cloth...
Only one grade of paper, no crazy 2000 grit, no powered buffers. I do sometimes do a step with the 600 grit dry after the wet sanding, the paper loads up and gets effectively finer and finer. The paper turns silvery when that happens, most of the time I don't bother though.
That looks great! I have to admit that I’m a little unfamiliar with jewelers rouge. Would you happen to have a link to what you used or any pointers on what to look for?
'Eagle One Mag/Chrome/Aluminum Polish'... Mother's has an equivalent, as I'm sure other brands too. It's all the same, jeweler's rouge paste stuff in a little tub.
