Well, I built a Spin-O-Matic device today to try spin coating TiO2 on to tile.
It sucked.
The machine was easy enough.
I dug through my DC motor box and selected a likely victim, dug through a pile of misc and found a pre-cut circle of wood leftover from a previous project, complete with a 3/8” hole that pressed snugly over the shaft of the motor. Woohoo! Life is good!
I drilled a bunch of small holes in the spin table so I could stick some pop rivets in to keep the tile from getting away at speed.
I had an old plastic salad bowl full of pistol brass waiting to be reloaded so the brass went in a metal can and the bowl got a new job as a “spew shield” to contain the mess.
Hooked it up to one of my DC bench power supplies so I can adjust the voltage/speed and yippee, I’m in business!
So. I mixed up some TiO2 in some some ethanol (Everclear) and stirred it up real good. In about 3 seconds it all settled out.
I mixed it up good again and immediately brushed a thick sloppy coat on to the tile and spun it up to speed and the stuff clumped and streaked and left a totally unsuitable coating.
I tried a wide range of different spin speeds, different ratios of TiO2 to solvent, ethanol, isopropyl, acetone, plain water, water with a touch of dish soap to change the surface tension… the results sucked every time. The stuff really wants to clump up as it spins off. The best results were with plain water. For some reason the alcohols seemed to make it clump more.
Obviously more experimenting needs to be done….
I’ll probably try spraying some to.
At least it didn’t take long to put the Spin-O-Matic together. It’ll probably come in handy for something.
Photos of Spin-O-Matic…
