Polishing ABS plastic with a perfectionism disabiltiy

[nago]

Hiya!

About a year back I got a used Vewlix C. I've done a lot of work on it, replacing all of the decroded and gummy wiring harnesses, a new control deck panel, all new buttons and joysticks, a new IO board, a new chassis fan, custom 3D printed brackets to mount the the exA arcadia to the board tray, custom pedal controls, a shiny new 4K monitor with a hadouken bracket, sanded and repainted the sun-bleached monitor bezels, ...

... One of the things I haven't yet been able to "fix" to my liking, though, is polishing up those red plastic arms on the control deck. Mine arrived scuffed after a lifetime of love and wear in Japan. I've heard that Novus plastic polish is just absolutely the way to go, but I haven't been having a tremendous amount of success with it. It does improve the look of the plastic, but my elbow grease perhaps just isn't *greasy* enough, and I am left with lots of very fine scratches that I cannot feel, but definitely can still see.

I tried microfiber with novus heavy, novus light, I've tried foam wheels and wool pads with an orbital sander and novus heavy/light, I've tried felt wheels with a dremel with novus light, heavy, 3M rubbing compound, etc. Nothing seems to quite get it ... perfect.

Recently, I took to wet sanding one of them by hand. I started at 320 grit and worked my way up through 400, 500, 600, 800, 1000, 1500, 2000. This improved the general consistency considerably and removed some of the heavier scratches for sure. I tried using novus by hand at this point and it looks ... well, about as good as it did before I started. I guess that's comforting that I didn't *ruin* it, but for how much work I put in ... I was hoping for better.

So, I tried wet sanding with an orbital sander using a foam interface pad. This had the benefit of being pretty gentle without leaving pattern marks from just back-and-forth sanding, but I kept getting very fine swirl marks in the plastic. I took some scissors to the foam interface pad and trimmed the velcro around the sides to make absolutely sure none of the velcro hooks ever made contact with the plastic. I switched to hole-less sanding pads. I used 1000, 1500, 2000, 3000, and 4000 grit. The plastic started to become pretty shiny even without a polishing compound.

I tried elbow-greasing the novus heavy scratch remover again. The plastic comes out pretty darn beautiful, but I can still see tons of little circular swirls if I glint the light off of it just right.

I tried going up to 5000, 6000, 7000, and 10k grit pads, but none of them really improved the look much beyond the 4k pad which is where I think I really maxed out.

At this point, I'm ready to throw in the towel and say "I guess good enough is good enough," but as a hail mary I wanted to ask folks out there what they've done to *really* get a proper showroom, mirror polish on their plastic parts - I can't say this is the sort of thing I'm going to do very often, but out of stubbornness I kind of just want to know where I might be going wrong, here! The scratches left seem *so fine and delicate*, yet I cannot seem to buff them out. Maybe there's a better buffing technique? I'm afraid of being too aggressive with the buffing and degrading my existing work, but I think I just cannot cut it by hand...

thanks,
--nago

(p.s., pictures of this nature are very hard to take, but I will *try* to shoot some later.)

 

[trashedcabs]

Get a DA polisher. I used to think Novus was kinda crap until I used it on a machine and it made a huge difference. If you're going all the way up to 4000 grit you should be able to go straight to Novus 2 and not have swirls, but I usually stop at 2000 or a quick pass with 3000 and then cut with a heavier compound before using Novus 2. I use 3D ACA 510 since I already have it for other things.

I have a Griots G8 for smaller parts like this and I usually use Rupes yellow foam pads.

https://www.griotsgarage.com/g8-mini-random-orbital-polisher/
https://www.amazon.com/RUPES-New-Fine-Pads-Performance/dp/B08GLJ1LLT

Also, if you're really going for a showroom finish, you could try applying a ceramic coating when you're done. This should fill in any ultra fine scratches that are left and help add gloss.

 

[nago]

Get a DA polisher. I used to think Novus was kinda crap until I used it on a machine and it made a huge difference. If you're going all the way up to 4000 grit you should be able to go straight to Novus 2 and not have swirls, but I usually stop at 2000 or a quick pass with 3000 and then cut with a heavier compound before using Novus 2. I use 3D ACA 510 since I already have it for other things.

I have a Griots G8 for smaller parts like this and I usually use Rupes yellow foam pads.

https://www.griotsgarage.com/g8-mini-random-orbital-polisher/
https://www.amazon.com/RUPES-New-Fine-Pads-Performance/dp/B08GLJ1LLT

Also, if you're really going for a showroom finish, you could try applying a ceramic coating when you're done. This should fill in any ultra fine scratches that are left and help add gloss.

Beautiful, thank you for your insight - I kept seeing posts where everyone says "Novus is great!" but it just was not matching my experience. I'll try to get my hands on a DA polisher, it's possible I can borrow one, but if not I'll check that one out. Thanks for the specific recommend on the foam pad, too!

 

[Dionea]

I recommend using Polywatch with makeup cotton pads. It’s a product watch enthusiasts use to polish plastic watch crystals. Don’t be put off by a few negative reviews; many of them come from people trying to use it on smartphone or smartwatch glass, which it’s clearly not designed for.

 

[nago]

Get a DA polisher. I used to think Novus was kinda crap until I used it on a machine and it made a huge difference. If you're going all the way up to 4000 grit you should be able to go straight to Novus 2 and not have swirls, but I usually stop at 2000 or a quick pass with 3000 and then cut with a heavier compound before using Novus 2. I use 3D ACA 510 since I already have it for other things.

I have a Griots G8 for smaller parts like this and I usually use Rupes yellow foam pads.

https://www.griotsgarage.com/g8-mini-random-orbital-polisher/
https://www.amazon.com/RUPES-New-Fine-Pads-Performance/dp/B08GLJ1LLT

Also, if you're really going for a showroom finish, you could try applying a ceramic coating when you're done. This should fill in any ultra fine scratches that are left and help add gloss.

The griots polisher has really helped. With the heavy scratch remover I think I've got the cleanest polish I've ever seen on this thing, though I can see some leftover circular scratches from my earlier sanding work quite clearly now.

I went back and buffed out what I could with 1500, 2000, 2500 by hand and polished again, but having some difficulty getting it totally spotless. This process removed some of the more obvious bad spots, but traded it for more fine scratches.

I suppose I'll just have to work on my sanding technique from this point, but it's certainly looking much better than it has in the past, I think I'm on the right track here.

Do you have any tips for knowing when it's appropriate to switch up to the next grit, or preferred sanding techniques? Should I be sanding by hand (light or heavy pressure, circular or back-and-forth?) or should I stick to trying to use the orbital sander with a foam interface pad?

At the moment I'm just working my way up through the grits with whatever method, attempting to polish, then observing what marks are left and more or less guessing what grit i need to drop back down to in order to make further progress. It's a very guess-and-check process so far.