SandBlasting Equipments & Supplies

Which Materials Can Be Used For Sandbasting Purposes?

First we need to diferentiate between materials to be sandblasted and materials used to sandblast.

1) Materials suitable to be sandblasted.

Glass, stone, metals, wood and plastics steel, brass, aluminum, pewter, silver, etc. In general, most materials be sandblasted except for diamond which is harder than all sandblasting media. Stone is regularly sandblasted as a way to create gravestones and memorials. Metal is sandblasted to remove rust and sharp edges or as a way to enhance adhesion of coatings and adhesives. Wood and brick is sandblasted to remove years of paint, oil and dirt and to produce a clean surface for staining and painting. Certain types of plastic can be sandblasted for decorative effects, but the work has to be done very carefully, as the plastic can be much softer than the abrasive and will wear away quickly.

2) Materials to sandbast.

By mixing air under pressure with a hard, particulate abrasive or media, material can be slowly abraded or worn away by directing the abrasive stream onto the surface of the material. The longer the abrasive stream is held in one spot, the more material will be removed. Moving the nozzle closer to the surface decreases the area being blasted, and increases the rate of material removal. By moving further away, the area increases and the rate of removal decreases. If the nozzle is held very close to the material, a hole can be abraded through the surface very quickly.

Among the abrasive media or materials used to sandblast we can find:

• Sand – Single use. Lowest cost at <$0.05/lb.
• Aluminum Oxide – Lasts 30-40 x over sand. Creates static charge. Moderate cost at $1.00/lb
• Silicon Carbide – Lasts at least 40-50 x over sand. Highest cost at $1.60/lb Cuts faster than AO, wears hoses and nozzles faster, has no static charge, and fractures leaving sharp edges vs. rounding of AO.
• Garnet
• Glass Beads
• Black Magic
• Walnut Shells
• Plastic Pellets

Sandblasting is the process of using compressed air to propel abrasive media at a surface to clean, (usually paint & rust),debur, or to prepare a surface for a coating of some sort.

There are two kinds of sandblasters: “Suction” / “Siphon”" & “Pressure” Blast Systems. Pressure systems are ten times faster & much more effective, but also quite a bit more expensive.

There are two basic kinds of sand blasters: Blast Cabinets & Portable Blasters

There is a huge variety of abrasive blast media out there each has its purpose. One you want to stay away from is Silica Sand. Blasting with Silica sand causes Silicosis of the lungs…Do Not Ever Use It!!!

If you are looking to blast hand tools, such as saw blades, wrenches, etc., I’d recommend blasting them in a sandblast cabinet. (A “Suction/Siphon” cabinet would probably be sufficient…)

Sandblast Cabinets have adequate lighting, a dust collector, and two gloves you place you hands inside to blast within the cabinet. One nice part about blasting inside a cabinet is that all the dust is contained, so no respirator is needed. They are also relatively quiet, and some have abrasive separators which allow you to get the maximum life out of the abrasive blast media & consequently save money.

Below you will find the steps of a typical “sandblasting process” inside a cabinet:

• Open Door
• Place Item inside
• Close Door
• Turn On The Power
• Place Your Hands Inside The Gloves
• Grab The Blast Hose, or Suction Gun
• Step On The Foot Pedal
• Blast Surface
• Blow-Off Item with Blow-Off Nozzle (Inside Cabinet)
• Inspect
• Repeat Blast If Needed
• Open Door
• Remove Item

QUESTION:

I have a building that is actually two adjoining buildings under one roof. This means that I have a large brick wall in the middle. I actually like having the brick there, but I would like to clean it. Is it possible to sandblast the interior walls? What issues do I need to take into consideration? If sandblasting isn’t an option, are there any other suggestions for cleaning the walls? One wall is 270 sq ft, so a wire brush isn’t really an option.

Note: everything is unfinished, so I have no framing to worry about and only subfloors.

ANSWER:

There truly is no difference in the process whether done outdoors or in. Especially inner city issues require that a ROOM/Shielded space be set in the area of the blasting. That might be accomplished with Tarps over framework in your case.

The blast operator most often wears protective OVER clothing, and certainly a mask/respirator, as well as a helmet of some sort. Containment is the issue, not the effectiveness of the task.