Laser Welding With A Tattoo Removal Gun

Dating as far back as the early 1960’s, researchers were zapping tattoo inks with laser light was an effective way to remove the markings from human skin. At the time it was prohibitively expensive. But the desire to have an undo-button for badge choices is strong, and thus the tattoo removal gun was born.

These days you can pick up one of these zappy, burn-y wonders for far less than a flagship cellphone put their high-power-output to alternative use. [Andrew] recently discovered that these devices can be readily repurposed into a laser welding tool with just a bit of work under the hood.

He first came across the technology via videos from [styropyro], whose work we’ve featured before. The tattoo removal gun features a YAG laser, which is pulsed to create a high power density. In initial testing, the pulses were too short and of too high intensity to effectively weld with; instead, the pulses simply cratered the metal.

After delving in further, [Andrew] discovered that by removing the Q-switch optical component, the pulses from the laser could be lengthened. This reduces the power density, and allows the tool to weld various materials even on its lower power settings. Success was found welding steel, titanium, and other materials, though attempts to weld copper and silver faced little success. Test pieces included razor blades and small screws, which could easily be welded with the tool. Results of the razor blade welding is spectacular, with a high-quality welding bead achieved by taping the laser to a CNC mill for precise movement.

It could prove to be a useful tool for those experimenting with complex projects involving bonding metals at very fine scales. If you’re pursuing something exotic yourself, we want to hear about it!

48 thoughts on “Laser Welding With A Tattoo Removal Gun

  1. This is soooooo dangerous it’s unbelievable. You need the correct laser safe glasses that can protect your eyes and then the correct protective gloves and clothing as the laser energy from direct exposure and reflections can cause serious burns!!!!

    DO NOT TRY THIS AT HOME!!!!!!!

    1. Dude, chill.
      A pair of suitable laser goggles that can be trusted is a must. But beyond that, the laser is only dangerous to other unprotected eyes (be very mindful of windows and open doors…)
      The burns are very small and localized + they instantly hurt, so there’s natural negative feedback to keep yourself out of the firing line, unlike with, say, a powerful X-ray source, where the damage becomes apparent only after some time and you feel absolutely nothing when roasting yourself with it.

      1. Bruce perens…. Yes agreed! Of course you’ re aware that it’s hard enough to ” mitigate”(lol) groups of people and injuries that may arise. Hopefully your precaution is headed. Eyes are simply irreplaceable!!!!!

  2. when lasers are used for removal of any kind it is classified as a medical device and controled by the cdc.

    heck the cdc even controls laser cutters featured on the board before.

    so i dont thinkyou can avoid medical classification by repurposing

    https://en.wikipedia.org/wiki/Laser and https://en.wikipedia.org/wiki/Laser_safety are 2 good places to read before getting involved in lasers as it is easily possible to burn your eyes even on lower power lasers.

    1. As a medical device engineer, I’m fairly confident that you mean FDA, not CDC.

      It’s easy to buy medical devices and supplies, even unexpired ones. Many devices may be labeled as “Rx only”, but they are not regulated like prescription medication and can easily be purchased by resellers. Check out esutures.com

      Also, FDA doesn’t really regulate off label use, even ones that are contraindicated. Just so long as the company selling the devices or the manufacturer doesn’t market the devices to be used in any way that they didn’t disclose in their submission.

    1. Keep in mind that in US there might be problems with importing a class IV laser.
      Also, invest in proper 1064nm (and/or 532nm if you plan on using the doubler crystal) goggles, the ones provided with the machine will jack shit against this kind of power…you have only 2 eyes and they’re worth way more then what a good pair of laser goggles cost.

      And this one will probably work, they all seem to have the same guts.

      1. What experience did you have importing class IV lasers? I’ve never had a difficulty with that, but then, I’ve always imported lasers in some kind of industrial product (CO2 laser cutter) or as an OEM module that was obviously not a consumer or medical product (multiwatt diode lasers.)

  3. I was given one of these about six months ago. It sits in my man cave, me being too scared to even plug it in.

    I have to admit to wondering if it could be useful for something other than the intended use but not wondering enough to ever plug it in.

    1. From the descriptions I think they use a blu ray laser diode. I’m also very curious about what it is capable of since with the short pulse it might still do something interesting.

  4. A reminder… familiarity breeds contempt (of common sense safety), and the consequences are irreversible

    https://www.photonics.com/Articles/Laser_Safety_Little_Mistakes_with_Big/a25167

    “Yet an examination of the record of laser accidents reveals that, in virtually every case, the injury results from a carelessly taken shortcut, a shortcut taken by someone who should know better but in the interest of expediency, takes an unnecessary and ultimately very costly risk.”

    1. Came here to thank you sharing this amazing article. This must be read by everyone which wants to do some work with lasers. There a plans to work and do some DIY with Nd:YAG lasers and already bought a laser safety goggles with high OD for infrared, but this is worthy to put that first in list when doing stuff with lasers.

    1. if you leave the passive Q-switch in and use the doubler crystal, it will blast the copper off. But – this uses a flashlamp as the pump source, they don’t last forever, especially with repetitive use. CNC-anything will quickly go through flashlamps.

    1. and is this really a picosecond laser or just a blue laser diode in a different enclosure?
      Because if it truly IS a picosecond laser, it would not be much safer. If it can blast off tattoos, it can blast off your retinas…

      1. I own one of these (bought just out of curiosity) and measured the actual optical pulse width of mine at 1.2ns using a 12GHz photo-diode on a 10GHz scope. These things use a gain switched laser diode, and they only last around 20,000 laser shots before the laser diode burns out.

  5. It’s interesting they have two different colors. I remember MANY years ago where semiconductor lasers were all pulsed, but didn’t think they still made them. Are these regular laser diodes pulsed way over their rating for a very short pulse? Laser diodes driving a Yag with a Q Switch? Something else?

  6. Plus when the camera bakes it’ll provide a pretty good clue that there’s way to much reflected light to be safe. And you can then design it to be better!

    Although if it’s on a CNC gantry I’m not sure why you’d ever want to leave it blasting dangerous light around instead of inside a safe enclosure.

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