Question about metals and powder coating

[lewis]

A few questions here. What I would like to do is buy a product that is already powder coated and then use the glowforge to etch into the powder coating exposing the bare metal underneath.

Q1: Has anyone tried this directly?

Q2: Is powder coating similar, or does it vary vastly from product to product

Q3: Is powder coating safe to laser?

Q4: Is there a risk to the glowforge if I laser through the coating and hit the metal underneath. The metal is most likely steel.

Q5: Is powder coating toxic, anyone know of the MSDN for powder coating or a resource for it

Q6: Other concerns I should be thinking of?

I’m not interested in doing the powder coating myself. I mostly want to buy the piece that is already powder coated, and then etch into it.

[kittski]

I personally haven’t tried anything powder coated in my GF, but it’s a really common laser product. Yes, the thickness can vary. I’m sure other more knowledgeable than me will chime in on the specifics, but there is lots of general information about it available on the web.

[lewis]

I’ve done a bit of googling prior to posting and have seen a couple of links that look like it’s not a problem. However, I am mainly interested in the safety issues to both the laser and my health. For that I have not found anything definitive.

[mad_macs]

I have lasered powder coating. It works pretty well. It won’t totally remove it, so afterwards you will probably be using something like baking soda and water, or soft scrub to get rid of the residue that’s left, you can do a second pass, but I found it to be a waste of time and laser for the most part. As far as I know there is no chlorine in it.

I looked the other day for a statement I thought @dan had made about the reflectivity of metals copper specifically. I was unable to find it. I think the concerns most people point to is the beam reflecting back through the mirrors and re-entering the tube. I think it’s hard enough to get the beam from the tube to the work, let alone all the way back into the tube. The beam would need to hit it just right, the workpiece would need to be perfectly square to the head, plus after the beam passes the focal point it diverges quickly, that’s why we can’t cut thick things. The laser has a short focal range.

[mad_macs]

From the Wiki-
The most common polymers used are polyester, polyurethane, polyester-epoxy (known as hybrid), straight epoxy (fusion bonded epoxy) and acrylics.

[jbmanning5]

@mad_macs

I looked the other day for a statement I thought @dan had made about the reflectivity of metals copper specifically. I was unable to find it.

This?

How short of a pulse can we get?

I would recommend an Othermill for quick PCB prototyping. Copper is a great mirror at 10600nm. For cutting it, you want a YAG, fiber, diode, or other laser. That said, you can (I’m told) get some fantastic, super detailed etching by putting a resist on the material, engraving it off with the laser, then chemical engraving. That doesn’t get you holes though.

[mad_macs]

That’s not the one I was thinking of. There are 3 or four good posts on this topic.

I also tried Kapton tape. It worked OK, but I had difficulty with the residue left from the adhesive interfering with the etch. Even after 2 passes.

[Slacker]

you should be fine. If you are having the piece powder coated you can check with the company doing it for the MSDS sheet on the paint they use.

@lewis

Q2: Is powder coating similar, or does it vary vastly from product to product

http://www.preferredpowder.com/powder_coating/textures_and_finishes/

here is a small list of companies that make it …

[karaelena]

I do it all the time. I mill out the part, powder coat it then engrave it in a jig I’ve made.

Test engrave on matte black on 6061 (Aluminum)

Before PC’ing.

After /w engrave

[lewis]

thanks for the replies. Good to hear that others have done it and that things should be fine. Looking forward to trying it!