Laser etched stainless steel residue

Hello!

I have been a huge Core77 fan for many years, and I’ve spent a lot of time on this blog, I figured I should start contributing!
However, my first post is a completely selfish plee for help, sorry…

I designed components as stainless steel parts with laser etched decals. After the laser process the parts arrive at our factory with a lot of ‘rust coloured’ residue around the decals. At the moment, the only way we can see to clean the residue is using an eraser to rub it away. This is obviously a manual process and very labour intensive. At the qc stage I’m seeing some haven’t been rubbed as well as others and it’s all a bit of a disaster.

Does anyone have any experience or advice on this process?

Huge thanks,
Hutch

Electro-polishing?

Hi nxakt,

Thanks for your reply! I should have mentioned sorry, this is a product for a consumer market where aesthetics play a big part. My goal is to get the stainless steel to look like stainless steel, whilst having a dark logo engraved into the surface. I usually find electro-polishing to leave steel looking really shiny and much less like steel and more like aluminium. I might be wrong though, is it a process you are more familiar with?

Thanks,
Hutch

We use a lot of electro-polished 316 parts, but as for the actual process, I do not have any experience. Good luck with the fix.

Thanks nxakt… electro-polishing would look a lot better on 316, unfortunately I use 304 as it makes knurling a lot easier.
Thanks for you help! :slight_smile:

Ultrasonic cleaning?

Could this be an issue to negotiate/resolve with the laser guys? It would seem you’re in the position of a ‘somewhat unsatisfied customer’…unless the price is too good to complain about. Is it laser etched (material removed) or something like a black coating?

Hi engio, I tried ultrasonic cleaning, but again it made the steel surface very shiny.

Hi Rara, the vendor isn’t much help I’m afraid. We are the only customer engraving so deeply into steel due to wanting a dark contrast between the logo and the steel. So his other customers apparently don’t have the same problems. I posted here on the off chance there is a simple fix I’m just not aware of due to lack of experience with this process. I’m guessing it’s not something others have come across. It sounds like I am just a very picky customer haha.

A bit of a shot in the dark, but maybe try a Magic Eraser (aka melamine foam), wetted with water, or maybe try a citrus cleaner. The foam is basically like a super fine abrasive…although if it’s an intricate engraving with a lot of sharp points and edges, it will tear up the foam pretty quickly. But it may work more quickly and/or better than a rubber eraser, and you can order generic foam blocks from China for a lot less than buying the Mr. Clean branded stuff if it winds up doing the trick.

Thanks Rara, ordered from Taobao (Chinese eBay). I will keep you updated of the progress. I hope this works, either way, thanks a lot for your help! :slight_smile:
Hutch

No worries Hutch! Hope it helps out, and I’d be curious to see photos if they’re not too sensitive to post of course. :slight_smile:

Hi Rara,

Great news, the foam works! Its not the perfect solution as its still a manual process, but the cleaning process is a lot easier and a lot less time consuming so I am very grateful for your advice!

Unfortunately, the worst of the problem is in the company logo itself, so i cant post pictures of that at risk of breaking forum rules and annoying my boss. But i did manage to crop an image to show you the rough problem. Please see the attached.
Image 004.png
Anyway, the parts look great and are now undergoing a saltspray test to ensure the foam hasnt had an effect on the Stainless Steel surface. Again, thank you for your help! Prepare for more production problems coming your way haha :slight_smile:

Thanks,
Hutch

Laser cutting isn’t best at depth milling, as your problem shows: it melts, burns and vaporizes the base material leaving swarf. Also, the laser beam “cuts” about .2 - .25mm wide, requiring the multiple passes your parts show, and lots more melted material.

Actual mill-engraving, chemical etching, dot peening, chemical marking or dedicated laser marking systems are much preferred, but probably that’s a different vendor than you’re using.

Hey Hutch, glad it worked out!

This is actually the sort of thing my day job should entail given my job title, education and especially background; but sadly doesn’t (I’ll be a free agent soon, on that note…). So fire away, I love a good problem! :bulb: