For most metalworking shops parts cleaning is, well, a pain. It's a non-value added step in the manufacturing process that while, often necessary, gets metalworking businesses into areas in which they have little or no expertise.

If a shop must clean parts, what's the best method? Of course there is no easy answer. It used to be possible to soak parts in a vapor degreaser and accomplish most soil removal requirements. That's no longer feasible because of environmental regulations covering atmospheric discharges and toxic waste disposal.

Options include parts aqueous and semi-aqueous washing units with agitation sometimes generated by ultrasonics. These methods work well for specific materials and soils but lack the kind of general purpose effectiveness that vapor degreasing provides. And, there is usually a waste disposal consideration with these wet processes. Then there are dry cleaning processes. These usually employ a grit which is accelerated to high speed to blast off dirt or other soils attached to workpieces. Glass beads, metal or plastic shot--even peanut shells--are versions of this process.

It's into this category of parts cleaning that SofStrip falls. They have successfully used this baking soda blast on applications in aerospace, paint removal for rebuilding and remanufacturing operations and in plant maintenance departments.

Baking soda as a grit blast medium offers several advantages over other solid mediums, according to the company. As each crystal of sodium-bicarbonate strikes the surface of a workpiece it crushes against the surface. When the crystal strikes a workpiece surface, the crystal is destroyed but in the process takes a bit of the soil with it.

Crystals can be sized to provide the necessary cleaning aggressiveness for an application. In part, because the baking soda crystal collapses on contact, removal problems involving getting the media from internal passages or small bores is eliminated. In addition, baking soda is water soluble therefore getting the media out of highly intricate parts is also simplified. They can be rinsed free out of the workpiece if necessary.

As a medium, baking soda is relatively soft. This makes it an effective blast medium for delicate substrates such as aluminum and thin wall sections like cylinder fins or aerospace structures. There is little or no peening action with baking soda blast. Baking soda is inert making its use and disposal less problematic than some other materials.

Soda-Blast.Com offers a full line of blast application equipment to accompany their baking soda media. For job shops with a variety of applications, there is a stand-alone blast cabinet available with interior dimensions up to height by width by length of 60 by 24 by 42 inches. There are systems available for higher volume/lower mix applications as well.

Cleaning workpieces and equipment is a necessity for many shops. Unfortunately there is no universal method effective for all cases. However, baking soda grit blast offers several advantages over other methods, particularly with regard to environmental and disposal considerations. That may make checking into a system for your application a good idea.—