In the first of a possibly occasional, but hopefully weekly, series I am going to focus in on a particular element of my work as a mixed media artist / designer / maker / tutor. I love the varied nature of my work and the projects I get to work on. This post is going to be about lasers, and specifically customising mugs.
The kit
I took delivery of xTool’s RA2 Pro Plus at the beginning of June. This rotary attachment is designed to work with their range of lasers. I have held off buying it since I purchased my F1 Ultra as I couldn’t see a use for it. But – with me now officially demonstrating xTool lasers to potential buyers, it seemed appropriate to get one.
It’s a versatile bit of kit, that takes some construction to set up. The Plus element includes a tilt mechanism (ideal for handled mugs) and a clip-on-and-off laser for marking the mid-line of the object to be engraved. It takes some mental agility to work out the placement of the design in the XCS software. It also takes some maths when working on tapered mugs to adjust the graphics – perhaps not the best first project to try.
The brief
Essentially, I wanted to use the new kit to customise the mugs I use in The Studio. I have etched the glasses with my logo in the past using an etching cream, and it seemed an ideal time to get the mugs to match.
The learning curve
Oh boy… it’s quite a steep start to the journey, but settles out after a little while. Complicating the issue was discovering which coatings were best to use for getting the logo onto the glazed ceramic. I’ve used the technique in the past on ceramic tiles – it’s the TiO2 (titanium dioxide) Norton white tile method. Apparently when heated, the TiO2 ‘stains’ the glaze and leaves the black marks. As to how to apply the white pigment, there are two methods I had at hand. A slurry of titanium powder mixed with water and school glue that is brushed on, or a highly pigmented white spray paint. I tried both on a scrap, chipped, mug, with the spray paint coming in as a clear winner:
I used Kobra spray paint. Initially, I struggled to remove the dried paint, so I masked off the majority of the mug. Clean off the uncovered areas with isopropyl alcohol before spraying with the white paint. Once the paint is dry, remove the masking.
Setting up the rotary attachment was fairly easy if you follow the online instructions. I used the chuck set-up as it works best for the tapered mugs, and it grips the mug firmly. It’s essential to get the engraving surface level. The included spirit level is for that reason, and the big knob on the bottom right sorts out the tilt angle.
As already mentioned, the Plus accessory pack comes with a magnetic centre line laser (bottom right). This requires some reassembly of the rotary, but, again, it’s simple if you follow the online instructions. Once in place, you line up the beam with the focus spots and square along the object. I used the midpoint of the mug handle as my reference.
The software requires the diameter or perimeter/circumference of the item to be entered. This sets the rotational speed of the engrave. For this mug, I used the midpoint of where the engraving was to take place.
Placement of the graphic in the software took some working out, but once I had done that it went smoothly. Framing (where the laser will etch) helps visualise the start and end points of the engrave.
The actual marking is done with the blue light diode laser and the two logos per mug took 5 minutes to process. I suspect I could have done it a little quicker, but the dark outcome was great and I wanted to keep it uniform across all the remaining mugs once I had started.
Once etched, it was time to remove the paint. I tried all sorts of different solvents, from the heady heights of acetone (which worked) to the floral aromas of orange-based detergent soaks (which didn’t). Isopropyl alcohol did the job too, but hand sanitiser gel was better and less volatile. Squirt some on, leave for a minute or so for the paint to soften and then scrub with a scrubbing brush and rinse under water. Stubborn bits came off with a little more gel and a magic eraser. Apparently, the alcohol combined with the hand-kind emollients acting together speed the process up.
Know your stuff…
During one of the demonstrations of the machine I did last week, I underlined the importance of material testing when starting out. Without my initial experimentation, I wouldn’t have got the results I wanted. Here, for example, is a side-by-side comparison of the result of lasering the two ways of applying the pigment. On the left, brushed on glue-water slurry mix, and the right, the spray paint:
The difference is noticeable, don’t you think? I could see the brush marks in the first and the etch is grey and has little contrast. The spray paint, on the other hand, is much blacker, has more contrast and the speckle from the paint spray isn’t as noticeable. One benefit of the slurry mix is that it is completely water soluble and just rinses off under the tap. It may be that I attempt at some point to airbrush the slurry onto the mug, but I am concerned the powder/glue mix will clog and potentially ruin the airbrush. Several even layers will be required to emulate the spray paint. It may be worthwhile to avoid alcohol fumes, but there is a trade off with the amount of time it takes in comparison to quick-drying spray paint.
What did I learn?
- Watch as many YouTube videos as you can find to get an idea of an accessory’s capabilities and set-up if you want to hit the ground running
- Don’t just rely on the included instruction manual. I found the online version (linked in the printed manual) much more helpful.
- There’s lots of information online about adapting graphics for tapered or round surfaces (or both). To make a circle look ’round’ on a cylinder, some stretching is required. Similarly, I had to do some warping on the logo graphic to keep it looking squared on the tapered sides. For the taper of 7 degrees, I used a vertical distortion of 1%.
- A measuring tape is your friend – one is included with the RA2. This is to measure the circumference and length of your object and helps in the spacing of the graphics in the software.
- Don’t be afraid to experiment!
Once completed, I ran all the mugs through the dishwasher to be sure they were clean of all chemicals. The etching didn’t chip, bleach or come off and I would consider it a great success. It’s advised not to use the method on the inside surface of mugs or on surfaces in full contact with food-stuffs, though fused pigment is considered food safe.