Inventables Community Forum

Paint/Resist laser ablation

If you are making PCBs or jewellery, you'll know about using resist, paint or other form of barrier to prevent the copper being etched by acid/electro etch.

I've always wanted a good way to remove resist without having to use UV reactive film and all manner of others ways. Yes, you can mill the copper but I'm not that happy with the results, and that is also no good for jewellery etching where there is no substrate.

So I've been playing with the jewellery technique of painting the copper with Matt black spray paint and then once dry, removing the areas you want to etch using the JTechPhotonics laser on my X-Carve.

Ignoring the fact these tests were using Easel, where you cannot turn off the laser while its doing Z up/down and rapids, it looks like the ablation will work well, maybe even better than milling.

I'll repaint these tomorrow and run the jobs again with a GCode export from Easel and change the Z movements to laser on offs and resend from Chillipepr.

Then they'll go in the salt water, low speed electro etch tank, takes a day or do, and see what happens. Once out of the tank, a quick wipe down with acetone will remove the paint. (Need to use an acid etch on PCB due to the break in conductivity once PCB tracks start to form).

Anyway, enough talk, here's an ablation piccie. Do bear in mind, if you try this that burning paint is really, really bad for you, so you need excellent air handling or proper respiration filtration.

Cheers

Ian

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Redone and ready for the etch tank (salt water, a D cell battery, couple of wires and a few hours).

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It's funny, even if you don't pay attention to the poster's name, I think many of us are going to be easily identified by our spoil boards as we go on smiley

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Very true smile

Maybe our forum avatars should just be a picture of them.

Ok, it's been etching for six hours and got approx. 0.3mm depth (sheet is 0.7mm thick).

Out from the etch tank, dried then soaked in petrol to remove the rest of the paint then washed. Wife will cut these out, clean the etch up, will become the same colour but a very textured matte surface compared to the design which will be flat and shiny and then will be turned into necklaces.

So overall, I'm very happy with the accuracy of the X-Carve driving the laser for detail work. Next thing to try is etching a PCB using this method but chemical etch instead of electro etching.

Cheers

Ian

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All cut out and into the media tumbler tomorrow.

Trying PCB creation using quick drying black spray paint on blank PCB then ablate it with the laser. Getting approx. 0.1mm outlines that should take an acid etch (will try it tomorrow).

Cheers

Ian

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The sea life have been media tumbled and made up as key rings. Photos were before final finishing.

Cheers

Ian

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As we get this technique nailed for jewellery making, we are starting to scale up and create more complex designs and bigger designs. :smile:

These are etched and cut out. They need cleaning, media tumbling and final finishing.

Cheers

Ian

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Very well done Ian.
Regards,
John

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And the PCB etched just fine in brine using galvanic etching (as the design is just isolation). Had to pop out in a rush this afternoon so it etched for too long and started to undercut. Even so all pads and tracks are isolated from all others confirmed with a continuity check.

So, if milling your PCBs becomes a bind, laser removal of resist does work.

Cheers

Ian

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I thought I’d give this technique a try. Can you share the laser settings (e.g. power, speed, etc.) you used to remove the paint from the metal? Thanks!

I was trying to do something similar today. Ended up cutting plastic tape with the laser and weeding the letters. I would really like to know settings to simply ablate the paint. I tried nail polish. (1.6W laser running at 300 mm/min) But it didn’t remove everything. If I get some more time. I was curious about shellac as it dries fast.

If I get some more time I’ll try some experiments.

so Shellac didn’t work well. I tried 1.6W 100% 100mm/min and 2 passes. It wasn’t enough to get through the layer. I then tried plastic tape again, same settings and this time after a light brush with a wire brush I was able to etch. Still not happy with the process but at least I have a method that works without weeding complex patterns.

Isn’t plastic tape vinyl? Vinyl is not safe to laser.

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Thanks for the heads up.

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