Can’t help with the original question but I have heard from two people who have had problems with paint chipping on the cut edges. they have tried slight rubbing & etching primer but it allegedly still seems to chip easily

regards

Paul

It is probably the result of the gasses used in laser cutters or the atmosphere reacting with the red hot metal that they are in contact with. So not all that different from mill scale. I did have a short conversation with a salesman once who said part of his job involved specialist gasses for large laser cutters.

Martin C

My understanding of laser cutting steel was that oxygen was used as it helped the cut, the laser provides the heat and then it is almost a self sustaining process. For stainless and other metals non reactive gasses are used to protect the metal as they will not oxidise as steel/iron does. I have started an oxy fuel cut then turned the fuel off whilst the cut will continue as the process is exothermic, providing the heat needed. Noel

Correct JA, the heat affected area will only be 3 mm from the cut at most.

Laser cutting does leave a hardened cut edge and paint doesn’t stick to sharp edges very well as it thins out on the pointy bit.

I imagine that plasma / laser cutters would not buy cold rolled stock as they don’t want any distortion as they cut bits out of large plates. Which means the black coating will be mill scale, just very thin. Phosphate coatings are more grey, but there is a phosphate and oil finish which would give the painting issues mentioned