Hello Collective
I’m having some issues with laser marking some Aluminum and I’m hoping someone might be able to help me figure out what I’m doing wrong.
I’m building a woodworking bench and adding in a custom router table. I decided to make my own insert plate with index marks for adjusting the fence on it. I tried using a fine point wood engraving bit in my CNC mill, but managed to break the tips on 2 of them had to remake the insert plate twice.
I read up on marking material with laser cutters, so got myself a can of LaserBond 100 and gave that a try with very mixed success. I can get very nice lines that are sharp, but they are… fragile at best. Some come off when rinsing the part under water, and the ones that stick will chip off with a light fingernail rubbing. My understanding is that this stuff is supposed to be durable like powder coating, so I’m puzzled as to what’s wrong.
I have a home brew LaserSaur with a 90W CO2 tube and a Ruida controller and a 75mm focal length lens. I’m using Lightburn for control.
The part is ⅜" thick 6061 Aluminum and it’s fully degreased. I only use water based cutting fluids, and after machining it got hand washed with Simple Green and hot water, then wiped with denatured alcohol and towel dried.
Before applying the LaserBond, I gave it an additional wipe with Acetone and then another with denatured alcohol to remove any Acetone residue.
After applying the marking paint, I let it dry for 15 minutes and then ran it under the laser. Most of the markings came off while being rinsed, and the rest with a just a light rub of my thumb. I tried and failed twice, and then went back to running some tests on a bit of scrap Aluminum with similar results. Pics are attached - the markings are speed (mm/sec) and power (%)
I let that sit overnight, but it could still be scraped off with a fingernail.
My next thought was that the Al is thick enough that the marking paint didn’t really get hot enough to bond to the substrate despite dumping 60-80W on it, so I put it on a hot plate and heated things to ~130C for 15-ish minutes. No luck.
Is there some other post-processing that needs to be done to harden it up, or is this just the nature of the beast? The spray tip seemed to clog every other stroke, so I had to continually pull it off, clean it out with alcohol and put it back - Did I luck out and get a bad can?
I was originally going to try Ceremark, but LaserBond had just as decent reviews and came with free shipping vs $20.
Sorry for the long post, but I wanted to get as much info on what I did put down. Thanks in advance for any advice
Take a look to see if this guy answers some of your questions. I hope someone can help.