Problem in sand blasting prosthesis

A. It is the nature of the beast. To remove metal, you are hitting it with a hard blast material that literally embeds in the metal chisels a tiny amount off. Since the material is very hard and is hitting with a huge force, some fractures on impact. Some of the material will remain stuck in the metal. One way to undo the problem is to use white aluminum oxide as the blast material. While not as durable as silicon carbide, it works quite well AND can be removed from the surface by a soak in a fairly strong caustic cleaner.

A. If the sand is silica or glass it can be dissolved by immersion in hydrofluoric acid (extremely dangerous). If it is aluminum oxide an immersion in a strong caustic will eventually dissolve it. In both cases the particles will leave behind a pore. You might consider using glass beads instead. They are round particles and will not embed as easily.

A. To understand material removal, you need to know the energy forces at work. There are 5 systems, 3 of which are mechanical. Abrasive blasting happens to be the most aggressive for speed and/or material removal. There are 3 main factors that control the process. Media size, pressure and angle of attack. Your problem maybe the last item; however, the others may contribute to this. Normally, I recommend, when possible, to always use ultrasonic cleaning after blasting to remove residue particles that are a result of any blasting process.

A. Dear Baydemir,

Why do you have to use sand blasting in your process. Maybe you can find a solution for your problem. But if you tell us the reason of sand blasting, may be some of us can help you to use different visions.

Best regards,

Good day.

Mr. Watts and Mr. Kenton have offered very good advice on the mechanical principals.
What is the process for the operation?
I would like to add to designate the particular blast material to each substrate being processed to avoid contaminating the blast material.
We use 30 PSI for glass bead and up to 80 PSI air pressure for aluminum oxide at 6-9 inches, 30-60 degree angle from the work piece.
Hope this helps.

A. As mentioned earlier, abrasive blasting is an aggressive form of material removal and is usually used on metals. The only way to get a relatively smooth surface is to use a small size or soft media and/or blast at a greater angle, but you will probably end up with a 28 RMS or more.