Cleaning & De-Coating in One Step using SofStrip Soda

Standard abrasive blasting is a dirty process, often reloading and even embedding the surface being cleaned with contaminants (grease, oil, tar & abrasive particles) in the process of removing the coating. Recycled abrasives compound this problem by loading increasing amounts of contaminants back into the substrate. SofStrip blast media effectively de-coats and cleans the substrate in one step; producing a level of surface cleanliness not available with most processes. The blast soda is not reusable thus eliminating the issue of blasting with re-used media. Coating adhesion relies heavily on surface cleanliness and a surface profile (orange peel effect) is added to the surface to offset this lack of cleanliness. No additional profiling is necessary as soda will re-clean the original profile and make it even cleaner than the original.

• SofStrip Soda’s Unique Cutting Action
  • SofStrip blast media offers the unique properties of sodium bicarbonate, the primary ingredient. The softness (Mohs Hardness = 2.4) and friable nature of this crystal (breakability) produces a unique cutting action with little or no effect on most substrates. For example, thick coatings can be removed from glass without any etching effect. With proper care, delicate substrates can be cleaned without damage.
• No Pre-Cleaning Required when using SofStrip Soda
  • For projects where the coating is covered with grease, carbon, salt or other contaminants, the more traditional blasting methods require the coating to be fully cleaned before blasting. This is required so that the contaminants on the surface of the coating not be driven through the coating and into the surface of the substrate, causing future coating failure.
• No Need To Re-Profile Steel when using SofStrip Soda
  • Standard grades of SofStrip media (without any hard aggregates) do not profile steel. SofStrip has a Profile grade of baking soda that imparts a profile on steel. When an operator removes a coating from a metal surface, he or she exposes the existing anchor pattern under the coating. Unless corrosion has occurred, there is no reason to re-profile the surface.
• Reduced Solid Waste when using SofStrip Soda
  • SofStrip blast media can be dissolved in fresh water. By dissolving the media and filtering out the contaminants the solution can generally be discharged to POTW treatment systems or open waterways, with proper discharge permits. Waste volume is generally reduced to less than 5% of the original waste volume. With increasing landfill costs and liabilities, this advantage becomes more important every day.
• SofStrip Soda is a Natural Rust Inhibitor
  • As long as SofStrip is on a ferrous metal surface, rust will not form. For rust to form, free moisture and an acidic condition must exist. In most cases, free moisture combines with carbon dioxide in the atmosphere to form carbonic acid. This acid releases a free metal (ferrous) ion which combines with oxygen (oxidizes) to form rust. SofStrip buffers acids, prevents the release of free metal ions and prevents rust.
• Reduced Clean-Up Costs with SofStrip Soda
  • SofStrip blast media performs roughly the same level of work (although somewhat slower) as sand blasting while producing 1/5 to 1/7 of the total waste volume. Although media costs per square foot are higher, site clean-up and residue disposal are significantly lower. The net balance is that total cost per square foot are about the same for both approaches.
• Benefits of SofStrip Soda In Waste Disposal
  • In most non-hazardous applications, the residue from blasting with SofStrip can be rinsed into sanitary drains or sewers which flush the residue to a water treatment facility, greatly reducing the clean-up time. Sodium bicarbonate is actually beneficial to waste water treatment systems.
  • For industrial treatment systems, where chemical neutralization is a major cost in water treatment, SofStrip blast media can often save significant dollars in waste treatment.
• Increased Worker Safety using SofStrip Soda
  • The safety of sodium bicarbonate as related to workers health is well understood, since it has been in use for some 160 years. The bicarbonate buffer system is the major extracellular buffer inside the human body, thus sodium bicarbonate is actually part of the body's normal chemistry.
  • Sodium bicarbonate and thus, SofStrip is not toxic via ingestion, inhalation or dermal contact, nor is it a skin or eye irritant as defined by EPA and OSHA. Any risk to workers is primarily the containment of the coating removed during the blasting operation.
• SofStrip Soda Removes Odors
  • The same odor absorbing effect seen in the refrigerator at home is present when blasting with SofStrip media. It not only removes the contaminants, it also reduces the unfriendly odors. This is particularly effective in fire restoration projects.
• SofStrip Soda Does Not Produce Sparks
  • Standard grades of SofStrip blast media (without hard aggregate) will not produce thermal sparks and are suitable for use in explosion proof areas; including refineries, chemical plants and grain elevators as long as proper grounding techniques are used to prevent a static charge build up.
• SofStrip Soda Improved Crack Detection
  • When cleaning metal surfaces for crack detection, standard abrasive blasting tends to peen the crack closed or pack the crack with abrasive, making crack detection more difficult. SofStrip media actually cleans out the crack, leaving it exposed and easy to see.
• No SofStrip Soda Residue Problems In Small Passageways
  • Standard grades of SofStrip blast media (without hard aggregate) are 100% water soluble. They can be used to clean critical engine components including those with small passageways. Once cleaned, the SofStrip residue can be thoroughly rinsed off by dissolving in water.
  • Other, more traditional blast media are not water soluble and if left after cleaning, can pack into small passageways and possibly damage an engine while on operation.
• SofStrip Soda Reduces Surface Acids
  • As a strong buffer for acids and alkalis, SofStrip eliminates acidic conditions on the surface of the substrate. For conditions with high acid levels, acid rain or boiler fly ash, blasting with SofStrip will reduce coating failures.

SSPC-NACE Standards

Without profiling, SofStrip will return blasted surfaces to the original level of clean that originally met the standards of both NACE and SSPC.

• NACE 1 (SP-5) White Metal Blast Cleaning
• NACE 2 (SP-10) Near-White Blast Cleaning
• NACE 3 (SP-6) Commercial Blast Cleaning
• NACE 4 (SP-7) Brush-Off Blast Cleaning
• (Note: "SP-#'s are surface preparation levels, not blast particle sizes)
   

Hardness Scale

SofStrip has a hardness of 2.4 on Mohs' scale of Hardness. The softness of this media means that it can be used to remove most coatings without harming the substrate.

Benefits of the Soda Process:

• Environmentally Sensible
• Non-Hazardous to Workers
• Non-Toxic Media
• Water Soluble Media
• Low Blasting Pressure
• Does Not Generate Explosive Dust
• No Threat Of Silicosis

Where Used:

• Industrial Maintenance
• Chemical & Petro-Chemical
• Oil & Gas Production
• Pulp & Paper
• Food & Beverage Processing
• Textile Mills
• Foundries & Steel Production
• Printing Industry
• Electrical Utilities
• Mining
• Aviation
• Military
• Commercial OEM's
• Automotive
• Electronic
• Marine
• Transportation
• Transit
• Highway
• Fire Restoration
• Building Restoration
   

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 degreas-ing 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 SoffStrip 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.

Cobblaster.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.—