Interesting point Frank. I started using a lot of water and also a few drops of mineral oil onto my lap discs. For me I think that it is working better than less water. But it is still too early for me to tell. But now that I have convinced myself to wear a mask, I may attempt dry or almost dry sanding on my expando unit. But I am curious and do not know the answer to this. Won't dry sanding on diamond wheels and discs cause them to wear out really fast? I will look forward to this answer before proceeding with dry grinding on my 80 grit diamond wheel.
I just thought of this, I have an Ameritool machine, basically the same as the all-you-need machine. They have resin discs. One thing that I have noticed is that when they get dry the cab begins to drag and it cuts a groove on the surface of these discs. I think you need at least some water drip to prevent this.
Scratches. Well my friend are you beginning to become impatient and wanting to move from one disc or wheel to the next? I have had that problem for a long time as well. The point that I want to make is that I keep telling myself that this is not a speed contest. It is art, and art sometimes takes a very long time to get it done and right. I keep telling myself that it's done when it's done. So what if it takes 2 hours on one disc or wheel. I will not sacrifice quality for anything. I know that I will have to make adjustments in the way that I price things because if I included a rate for how much time it actually takes my product would be astronomical. So in the end, I just go by like I just said. I will not move from one wheel or disc until I am satisfied that the scratches are out. Sometimes though spending more time polishing will help a lot. I will sometimes go through the entire process to identify problems and then go back and rework if necessary.