Any rock can be etched to create a sharp quality finish. River rock, Stone, Marble, Granite, Quartz etc. is all possible. Paint filling can enhance the look as the finished etching will not have a lot of contrast especially if it is a light coloured stone. A black stone will provide contrast as the etched area will have a grey finish to it providing a soft contrast that can look great.
Smooth and rough surfaces can both be sand blasted. A rough surface will probably require RZ2 adhesive to ensure the bond between the rock and the SR3000 resist whilst a smooth surface does not need any extra adhesive. We also recommend SR3000-5 resist be used as it is a stronger resist for deeper etching and you will probably want to paint fill so SR3000 5 mil works best with paint fill.
On rough surfaces use the RZ2 adhesive . Spray this onto the rock surface and let it tack off. Now you can apply your SR3000 resist to the surface. This creates a double adhesive contact making the resist stick well to the rough surface. You will probably have to do a bit of scrubbing to remove all the adhesive after removing the resist but it should come off pretty easily.
On Shiny and smooth surfaces you do not need the RZ2 adhesive double tack. The resist will go straight onto the rock surface and stick well to it. However sometimes if the rock is quite cold the adhesion of the SR3000 resist may become difficult. If the rock is cold you can warm it up with a small fan heater to take the chill of it. The resist will then stick really well to the surface. Alternatively you can warm the resist with the fan heater or a Drying Cabinet. Warm resist sticks really well. This
Normal Abrasive is used, we recommend Aluminium Oxide 150grit. A rougher abrasive will etch faster but why bother having to clean out your pressure pot and change it back to 150 for other products when you are finished the job. Stick with one abrasive for all jobs.
Paint filling is easy using a spray can or spray gun. Apply three light coats while the resist is still on.