Powdercoated Stainless - Residue won't clean off. What setting to adjust?

We picked up some powedercoated stainless steel flasks from JDS, and after some trial and error on a sacrificial flask, we settled in on 1000/100 450 LPI (which happens to also be the same settings for a silver iPhone)

We got great results on small tests, with a little residue that easily came off with some 91 alcohol and a microfiber. When we did the full size artwork on a fresh flask, the sides were super clean steel, but the center (crown) had residue that wouldn’t come off with the alcohol.

That section of the flask is slightly closer to the laser, due to the shape of the flask.

My question: Do I need more or less laser? I’m not wanting to keep throwing sacrificial flasks at it to test, and I only have one left now. If I slow down the speed, it will leave the laser on it longer. Will that leave less residue so I can clean it? Or do I need less laser so it doesn’t “bake it” into the stainless.

Thanks for any assistance.

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So the things that might be getting you here are distance to the laser and thickness of the coating.

It’s hard to know what to advise because we don’t know what height you’re targeting: are you setting the height manually, using set focus? If set focus, where are you aiming the focus? Are you doing this without the tray? If so, how high are you raising the flask? How thick are the flasks?

Take us through your focus height process in detail and we might have more ideas. As it stands there are a few too many variables to know what to suggest.

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Sorry, assumed everyone used “Set Focus” …

No tray. Using a wooden cutting board to get the flask up into the focus range. Then using Set Focus at the center/middle of the flask, so focused at the crown.

Kiddo used acetone to clean it and it cleans OK, but I know acetone and powdercoat don’t mix.

I’m getting a successful burn. So I don’t need help with that part. I just want to know if I need more or less laser to get the residue to not be there when we blast powercoat off stainless.

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In my limited experience, powdercoat does not do well compared to anodized steel or aluminum. Powedercoat sets with heat, so the stuff that does not vaporize, such as along the edges, is as hard as the plain powdercoated surfaces and very difficult to remove.

Anodizing is a different process, it’s effectively an atomic-level dye, so it vaporizes away with no residue. I have anodized steel “business card”-sized pieces I use to create tags and such, and it produces very nice results.

Again, that’s just my experience. I tried powder-coated parts a couple of times and was not happy with the results. The better approach was to use a laserable coating like cermark to positively burn/set a design into a metallic surface. That gives a positive, not negative, impression.

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Thanks. We may try some anodized in the future. But for now, with this project we want to do, we are working with powdercoated stainless.

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If it’s truly focusing at the crown, then any deviation of height will reduce the effective power because the laser won’t be as focused.

If the coating is thicker at the center then you’re probably underpowered. This is my best guess.

It’s metal. I’d be more likely to overpower it. The metal can take the heat.

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Report back if you come up with a way to do it cleanly.

I ended up tossing what I had and buying anodized versions instead. They were gifts and I was not willing to live with what it produced.

… I actually had three, and one was for testing, that was the one I tossed. The other two I just gave away in their original state.

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See, that was our thought as well. If it’s focused at the crown, the laser is lower powered at the edges where it falls off slightly. But the edges where it falls off, are the only spots that are perfectly clean. The crown, where the laser would be the “hottest” and most accurate … is the part that leaves gunk on the stainless.

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Sadly, Elflyguy, the boxed gift sets are only available in powdercoat.

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Yeah. I’d take a used one that didn’t turn out and try hitting it with a bunch more power. See if that solves the problem. I still bet it’s about inconsistent coating thickness.

Using a ruined flask will keep you from wasting another.

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Before moving the flask you could also adjust the settings to try mimic what you think the edges are getting and rerun the piece a second time.

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Hey y’all … I realized I never came back to update this post. Long story short, our settings are good 1000/100/450 and it’s just a sticky residue that gets left behind. No amount of power/speed adjustment would eliminate the residue.

But … LA Awesome cleaner, full strength, wipes it right off. Problem solved. Super clean etches in the powdercoat, shiny stainless beneath.

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Thanks for sharing your tips and settings with us! The flask looks amazing! Do you mind sharing where you can buy the cleaner?

Actually I just ran a search for the cleaner, and it looks like you can purchase it pretty much everywhere from a Home Depot to places like Family Dollar! I had never heard of it before now.

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