Engraving stainless steel coated with teflon

[Aaron Vogt]

I'm trying to engrave this rod that is stainless steel coated with teflon. The sample i have, the lettering is a white silvery color easy to read from a distance. When I engrave it, it comes out a brownish color and unreadable from a distance. is it even possible to get the color change with just lasering?

i have i m series pinnacle laser (m25 i believe)

ps. i'm self taught and new to laser engraving

any help is greatly appreciated
thanks!

[Gary Hair]

Two things you are not supposed to laser - pvc and teflon. Both emit toxic gasses when lasered and can kill you. Others will say there is nothing to worry about, the choice is yours...

[Aaron Vogt]

I relaize that... we have it air filtered going out of the building..

[Bill Cunningham]

I relaize that... we have it air filtered going out of the building..

Teflon fumes are fatal for birds, and it doesn't take much..

[Gary Hair]

I relaize that... we have it air filtered going out of the building..

That's not good enough from what I have read. You might want to post signage so that innocent bystanders aren't poisoned by your work...

[Aaron Vogt]

not trying to be rude here but i haven't died yet, no has died yet and there are no birds falling out of the sky by our building. its a thin coat, probably not pure teflon. i'm just going off what i was told, but my question wasn't either or not it was safe to do...

[Angus Hines]

Well you may not be dying. But you won't be in this business long, as the gas emitted by engraving either of these materials is highly corrosive to your equipment and failure will be eminent !!!!!

As for your other question I don't know as I dont engrave things Im not supposed to in my machine !

[Doug Griffith]

You only have to die once to learn your lesson.

No really, you said you were self taught, new to laser engraving, and any help is greatly appreciated. You were being helped by being given information to keep you and others around you safe. Including birds.

[Richard Rumancik]

Aaron, you can find some info on cutting and marking Teflon on the Synrad applications site; eg
http://www.synrad.com/newsletter/0304-2/0304-2.htm

They do indicate that you need to take precautions with Teflon but with a proper exhaust system it should be doable. In any event, Synrad shows it can be cut. There is very little material removal during marking; it is quite different than cutting where a large volume of material is involved. Many Teflon films are only a few thousandths of an inch thick. The laser companies will give blanket prohibitions for liability reasons, but that does not mean that with a properly engineered system you can't process these materials. The manufacturers know that many users may have inadequate exhaust systems and it is just easiest for them to say "no". Then the onus is on the user to ensure that what they are doing is safe.

Laser marking of Teflon wire insulation is common but I don't think a CO2 laser is used for that. They tend to lean toward UV lasers because CO2 damages the insulation too much. Perhaps UV is what was used on your sample. I have some doubts that you will get acceptable results. I don't think you will find much on the Internet on the subject and will just need to experiment. I assume that you are probably trying to get a color change without actually removing all the material down to the base. Teflon does not melt and the brown color is probably the result of thermal degredation (burning) of the film. You might try a much lower power and play with ppi settings to see if you can generate a contrasting mark without burning the film.

One other thought - are you positive that the mark was made AFTER the film was applied? Perhaps the rod was marked and then coated.

[Aaron Vogt]

positive. the stainless is sandblasted underneath the teflon coat. i'm getting through the teflon just fine but i'm not doing much to the sand blast.

[Craig Matheny]

the stainless is sandblasted underneath the teflon coat. i'm getting through the teflon just fine but i'm not doing much to the sand blast.

If you think the laser will do something to the stainless that is sandblasted it won't with out cermark or other marking material all you will do is watch a bright spark dance on the rod.

[Alan Reeves]

I work at an environmental engineering firm and I ask one of the guys that deals with all the nasty chemicals why you should not burn pvc. He told me that it released HCl (hydrochloric acid) which would not be good for the metals in a laser. He also said that burning teflon would release HF (hydrofluoric acid). I mentioned that I had never heard not to laser teflon (until this post) He said that the HF would not do much to the metal but would eat through the glass. So, regardless of the air assist, fume extraction outside, etc, if you try to etch pvc, you are most likely damaging the metal in your laser. If you try to etch teflon, you are most likely damaging the glass (lenses, laser tube, ???) in your laser.

The laser is not designed to remove the fumes to an extent etching pvc or teflon is in any way safe (of course, that is my opinion). Hope that helps

[Michael Hunter]

Adding to Alan's post -

When PTFE is heated to degradation (as happens at the edge of the beam and the "heat affected area"), it gives off nanoparticles of resin.

If these particles are breathed in, they cause 'flu-like symptoms and can make the person affected feel very ill indeed.
Normally, complete recovery occurs after a few days, but repeated exposure can cause long-term lung problems.

All this is quite separate from the release of flourine by full vapourisation at the point of focus.

Very nasty stuff indeed.

[Martin Boekers]

not trying to be rude here but i haven't died yet, no has died yet and there are no birds falling out of the sky by our building. its a thin coat, probably not pure teflon. i'm just going off what i was told, but my question wasn't either or not it was safe to do...

WOW.... is this how you deal with environmental issues? We ALL have a responsibility to control hazardous effluent. The one's that quote "i haven't died yet, no has died yet and there are no birds falling out of the sky by our building"
tend to make a bad impression for those of us that do take responsibility for our work.

Yes, you may not have asked if it was safe or not, but all this forum was trying to do was to point out hazards that maybe a newcomer was not aware of. (7 posts lead me to be you are a newcomer). One thing to remember this is a public
forum and is archived. If something should happen at your shop evironmental or OSHA (if you are from the USA) just an easy search will find these posts. What you just said shows a blatant disreguard for caring about the effluent
you are producing and the hazards you may be creating. You may or may not want to think this over a bit.