Thanks.
That is what i thought as well. His use of PVA water suspension of TiO2 for Tile engraveing.
This discussion ,can benefit from additional context and content. Such as other applications of TiO2 and other methods for Tile engraving and other Materials used to mark with a laser.
Thus the branching of the discussion to metal, mustard, primer , etc from the main trunk .
Cool
Thanks again for the warning to us all about Zinc Oxide Vapors.
My reading of some relevant info shows some danger from zinc oxide fumes,
My reading also suggests this is (easily?) mitigated with proper exhaust setup and filtration and use of respirators.
Laser Engraving Zinc Oxide is quite different from Welding Galvanized Metal, in the precise and localized application of heat.
Anyway ZincOxide /Titamium Dioxide use in this manner is very similar and Zinc does work on metal in my few tests.
However, I’m not getting great results here. For the same speed and power, it’s not as black, and microscope shows many “puddles” aren’t filled with the black glassified stuff.
Looks like not enough TiO2, so I gave it another TBSP for a total of 2. Still spreads ok, burns more black but not as much as I got with the spray primer.
Also weird, my line width with the spray primer actually showed a significantly smaller spot size, like 0.1mm line interval. At 0.1mm, the PVA glue version was much wider.
Am I right saying you use a CO2 laser? If so I can not help much as I do not have any experience of CO2 lasers. All my settings refer to a 40 w diode machine. Have you done a burn test with my method. Getting the speed and power right is important. I would also test with a weaker mix as two much TiO2 could block the lasers path.
Have you watched the video in Jacks post by Sadler, he deals with CO2 lasers and his info may help.
I do thorough test burns. I just do a stepped gradient and put it in grayscale mode at 10-30mm/s 100% max/0% min power so you can see what it does as power increases to 100%.
I went ahead and added a third TBSP of TiO2 and shook hard (I’m keeping it in the Elmer’s glue bottle) and it seems to mix thoroughly. Brushed on. Doesn’t seem much better. Looks like it’s inconsistent thickness too because it’s too thick to self-level, I should try to add water.
Hmm, intriguing that it could be too much. But I look at the gradient- part isn’t through the coating, then it’s definitely through but all white melt. Then a bit grey. Then inconsistent spatterings of black.
What’s more, I see droplets of black melt sporadically balling up in the coating beside the last line. That suggest the coating is melting but first collecting itself into these balls on one pass, then the next pass may hit a ball and form the black puddle but only at that one spot. This explains the spattered appearance of black puddles in grey melt rather than a solid black. This seems like not enough TiO2 to form a consistent layer.
I’m usng the same laser and getting excellent results. Here is my method For best results with a brush on method measure out 100 ml of PVA glue and I now add 3 tablespoons of water plus two drops of liquid hand soap. Mix thoroughly. Now add one full tablespoon of titanium dioxide to a flour sift. Slowly mix sifted powered to your PVA as you stir. Make sure you mix well. I now strain this mixture through the flour sift into another vessel. Paint on clean tile as you would paint anything with gloss paint. I dry with hairdryer and laser at 1000 mm/m 80% power. 40 watt diode laser. Hope that helps. Substitute hand soap if necessary for washing up liquid.
I don’t think mixing is the problem. My TiO2 was a fine powder, no clumping. I’m not seeing lumps in the layer. When I get the glue on my fingers, even if it’s thin, it dries to a solid white.
Shaking seems very effective for mixing, as long as you have some headroom in the bottle, which I do. Again, no clumps coming out. I do get air bubbles though, but they’re gone by the time it dries. Now if I saw inconsistencies where the black layer has regional voids, I’d say that would be because it was underneath a dried air bubble, but I’m not seeing that problem.
I did take a tile and dumped some more TiO2 powder on it then brushed the mix over it to increase the TiO2 content for that one tile. I think I tracked which one I did that with, I don’t recall it getting notably blacker.
Additionally, I do see where single dashes from dithering light areas commonly do not have black melt puddles in them, just a white shallow hole in the ceramic. It looks like it needs to be adjacent to more burn either from a multi-pixel dash, or from an adjacent line
Have just noticed you are quoting mm/s not mm/m1 which is the recommended setting in Lightbrun for diode laser machines. I don’t know if this could be where your settings are different to mine and what difference it makes. I use mm/m and laser at 1000mm/m 80% power on an Atomstack 40 watt laser machine.
The speed is the same … 100mm/s is 6000mm/m there is no difference in how fast the machine is going as they are the same.
If I run my co2 at 1500mm/s that’s 90000mm/m … same speed
As a warning, the Device manager always appears to display the units in mm/m for a diode type … Even though it’s set to mm/s in the Settings, the device manager is displays in mm/m…
I have all of mine set to mm/s as I’m used to how fast I expect the machine will go…
Maybe that’s the default for grbl… don’t know… just watch it if you interchange them.
I send an email this morning asking for advice about Titanium Dioxide issues I have as the spray paints we have here do not have Titanium Dioxide or it’s not mentioned. I am definitely going to try your method. One thing I noticed you did a great engraving on tiles that are not 100% White or smooth surface. It’s impressive. Will look around and order Titanium Powder for testing work. Thank you for you advice and contribution. John
John as an addon to my post, I am now etching unglazed ceramic coasters from Amazon. The same method and the results are fantastic. Well worth a look at just £17.99 for 12 including cork self-adhesive backing disc. Do show us some of your work.
Here are a few pics of the coasters. These I did for my local garage in appreciation of their very good service. They give me extra care as I’m disabled.
Hi Ron/Jack. I’ve gone through both your comments and recommendation on Laser engraving on Ceramic Tiles using Titanium Dioxide. Thank you. I’ve ordered the Ti02 and waiting for arrival soon. Being in Singapore this place is highly humid so if I use Titanium Dioxide and mix with water to spray with Airbrush I supposed it will not dry up so quickly. If it does can I add some wood glue just to hold it a bit longer to dry. My Diode Laser is Neje N40640 which is 40W. Thank you for your recommendations. John
I use a heat gun on the tile… Doesn’t take long to dry… It also allows you to see how well it’s distributed.
It has to adhere to the tile or it will puddle. I clean mine with Windex window cleaner and dry it. When I put it on, sometimes it will puddle and I have to wipe it…
You just have to ‘fool around’ with it… I found adding food color is helpful…
Thank you Jack for your quick reply. I will try out as soon as I received my order. I’ve gone through Youtube where several users have been kind enough to advise usage of Ethanol besides water. If I use water I’ll also try to ad some wood glue to test. Hope I’ll get some satisfying result. Thank you again and have a great weekend. John
Food safe does not mean it’s good for us. The crap they put in processed foods to make money will blow your mind. Food and cosmetic grade Titanium Dioxide is considered safe in small amounts by the US FDA but is not considered safe by the European FSA.
I personally keep away from Titanium Oxide. Especially if it’s pulverized and made airborne by a laser beam.
Titanium dioxide is carcinogenic if inhaled
Educate yourselves on the subject of Titanium oxide. Don’t trust a wolf to give you a true count of your flock of sheep.
