Laser Engraving Project using 50 watt fiber laser.

[pontiac428]

Randy, yes, the Lead-Chek works perfectly for screening. The test is sensitive around 50,000 ppm, which is the lead paint screening threshold (0.5%). It's just a color test, so no concentration, but if the swab turns red the surface is hot at the HUD/EPA level, which is good enough for this non-production work.

The powder may or may not be representative of the base metal. It has been blasted to vapor with a laser beam, which would volatilize the lead, or at least a portion, into the atmosphere. Roughing with some emery cloth and testing the surface of a coin with a Lead-Chek would work just fine, and it's probably the best solution for a home engraver to screen materials.

 

[sn8kboy]

The fumes and some of the powder is sucked up and filtered in a very large filtration unit that comes with the laser when you purchase it. Wearing an appropriate mask is something I will have to look into as well. If anyone has some recommendations when it comes to an appropriate mask that would be appreciated. When you look at the picture of the brass powder above you will notice it is moving off to one side and that is because of the vacuum filter device. It looks like I will also have to take care when disposing of the filters when they need replacing as well. The filter unit is the large box shaped device under the table to the right.

I found the lead-check kit on Amazon and have ordered it.

Lead-Check

 

[pontiac428]

That looks like a nice setup. HEPA is fantastically effective and activated carbon pulls out organics. So, the same components that make a good filter for the mists and vapors of laser etching also make the best filters for a respirator- P-100 HEPA pre-filters with OV cartridges for organic vapor. They are a common cartridge for any respirator you may have.

At the same time that I am impressed by your power and filter units, I am appalled that LaserStar isn't selling an enclosure with the kit. Enclosures not only block hazardous light from the beam, they provide channeling and containment for air flow and are a requirement under OSHA (but not regulated for home use- you aren't exploiting workers at home, are you?).

Laser etching is also widely used on plastics. The most common being laminated plastic with a contrasting color core. Material of this type is almost always PVC, which is fine, but forms a lot of HCl vapor under the beam (that's acid gas). Another detail is that laminated plastics and weldable plastics are doped with PVF so they stick together. The F is for fluorine, which (as HF) you don't want to accumulate in your body at any dose. Another etching substrate is thin anodized aluminum plate. Same thing, laser burns through the anodizing to reveal color-contrasting bare aluminum underneath. Well, the dyes that are in the anodizing contain other metals as well as chemical structures full of heteroatoms like nitrogen and oxygen. Those two bad boys can rearrange their electrons like it's no big deal, and the beam has plenty of power to oxidize, reduce, and produce radicals, resulting in any combination of atoms, many of which are likely to form a covalent bond with or thieve an electron from your lung tissues and eyes.

That's my take on laser safety and health. We all assume risks that we're comfortable with, but I know professionally that end users aren't always good chemists so the hazards need to be explained. The solutions for controlling exposures are easy- maintain your vent and know your material.

 

[sn8kboy]

That looks like a nice setup. HEPA is fantastically effective and activated carbon pulls out organics. So, the same components that make a good filter for the mists and vapors of laser etching also make the best filters for a respirator- P-100 HEPA pre-filters with OV cartridges for organic vapor. They are a common cartridge for any respirator you may have.

At the same time that I am impressed by your power and filter units, I am appalled that LaserStar isn't selling an enclosure with the kit. Enclosures not only block hazardous light from the beam, they provide channeling and containment for air flow and are a requirement under OSHA (but not regulated for home use- you aren't exploiting workers at home, are you?).

Laser etching is also widely used on plastics. The most common being laminated plastic with a contrasting color core. Material of this type is almost always PVC, which is fine, but forms a lot of HCl vapor under the beam (that's acid gas). Another detail is that laminated plastics and weldable plastics are doped with PVF so they stick together. The F is for fluorine, which (as HF) you don't want to accumulate in your body at any dose. Another etching substrate is thin anodized aluminum plate. Same thing, laser burns through the anodizing to reveal color-contrasting bare aluminum underneath. Well, the dyes that are in the anodizing contain other metals as well as chemical structures full of heteroatoms like nitrogen and oxygen. Those two bad boys can rearrange their electrons like it's no big deal, and the beam has plenty of power to oxidize, reduce, and produce radicals, resulting in any combination of atoms, many of which are likely to form a covalent bond with or thieve an electron from your lung tissues and eyes.

That's my take on laser safety and health. We all assume risks that we're comfortable with, but I know professionally that end users aren't always good chemists so the hazards need to be explained. The solutions for controlling exposures are easy- maintain your vent and know your material.

LaserStar does make an enclosed unit but I did not want that unit because then you are limited to the size of the enclosure for the parts I want to engrave. 90 percent of the parts I want to engrave would have fit in the enclosure but the other 10% would not. Also to answer your question I am not exploiting workers at home.

 

[sn8kboy]

OK - now I am getting curious, and seeking some fact about what happens when one is using high power lasers to ablate metal.
I have seen a list of various brasses. There were more than 50 types in various alloys.

The first obvious thing is that all the metals used in brass are extremely toxic when in finely divided form, or in solution. Zinc, copper, tin, lead, arsenic, aluminium, manganese. Basic brass (bullet cartridges) are 30% zinc, and 70% copper. Free machining brass has 3% lead.

So when the laser hits the metal, where does it go? Is it vaporized? I am not sure what kind of mask would stop it being breathed in.
It is good to see that at least some, hopefully most, of the removed brass ends up as powder around the job. Would that be re-condensed brass, or "sputterings"? I would treat that dust with respect. It looks like an extremely poisonous powder that can end up in the body.
Here, I am entirely with @pontiac428. What he said about lead is true also for other metals. We can add dementia and painful neuralgia. Copper is so toxic that microbes on brass pull-bars on doors only survive for a few minutes!

The coin badges that @sn8kboy made are just fantastic!
Paul, maybe you can let us in on some of the stuff you have to watch out for, (I mean aside from not getting exposed to a 50W laser )

To answer your question as to what to watch out for I would say that the laser will not burn you unless you keep you hand or other appendage out of the way of the beam. You defiantly need to be careful about trying to engrave items that are flammable like wood. You can engrave dark woods but care needs to be taken not to start a fire. As mentioned proper ventilation and masks should be worn when engraving material that could be harmful to your health. To answer your question bout the brass powder produced when engraving I like your title of "sputterings" as the best definition.

 

[sn8kboy]

I plan on purchasing this mask to wear while engraving and handling parts. Do you guys think this is sufficient?

HEPA Mask

 

[WobblyHand]

I plan on purchasing this mask to wear while engraving and handling parts. Do you guys think this is sufficient?

HEPA Mask

HEPA filters are good for filtering particulates. They are not good for chemical or metal vapors. You should consult a website on respirators for the correct type of filters and masks for your use. Depending on what you are working on, that stuff can seriously injure, sicken or kill you.

 

[pontiac428]

The NIOSH respirator code/approval number given on the Amazon listing is false. The code given is for Klein brand masks with GVS-UK brand filter cartridges that are particulate only (that's not a bad thing, just a distinction).

Respirators are cheap. Buy a 3M, North, MSA, or Bullard brand respirator with real approval codes. They're like $25 for a 3/4-mask plus cartridges.

Metal fumes/mists/vapors, as with all aerosols, ultimately behave as particulates and only need to be mechanically captured. Organic vapor, acid gases, and chemical fumes require chemical filtering. Activated carbon covers the gamut, with some exceptions for various gases (oh, for example, formaldehyde, cyanide, hydrogen sulfide, that sort).

 

[WobblyHand]

The NIOSH respirator code/approval number given on the Amazon listing is false. The code given is for Klein brand masks with GVS-UK brand filter cartridges that are particulate only (that's not a bad thing, just a distinction).

Respirators are cheap. Buy a 3M, North, MSA, or Bullard brand respirator with real approval codes. They're like $25 for a 3/4-mask plus cartridges.

Metal fumes/mists/vapors, as with all aerosols, ultimately behave as particulates and only need to be mechanically captured. Organic vapor, acid gases, and chemical fumes require chemical filtering. Activated carbon covers the gamut, with some exceptions for various gases (oh, for example, formaldehyde, cyanide, hydrogen sulfide, that sort).

Was hoping you would chime in. Thanks for the corrected info.

Buy the correct mask and filters for the job. And 'eff Amazon for this. Go to a real supplier, your well being could depend on it.

 

[pontiac428]

Buy the correct mask and filters for the job. And 'eff Amazon for this. Go to a real supplier, your well being could depend on it.

I'm big on this as well. Not sure that counterfeit personal protective equipment is worth the savings.