Notes

SOLVENTS, SOAPS, AND CLEANING SOLUTIONS
General Rules for Using Chemicals

There are many different types of chemicals used in automotive technology. This lesson will look specifically at some of the more common types of solvents, soaps, and cleaning solutions. First, let's look at some basic rules that apply to working with any type of chemical.

Follow the manufacturer's recommendations.
Carefully read the product label for correct uses and hazards.
Work to prevent spills, damage to the vehicle, or unsafe situations/conditions.
Properly store chemicals and used rags.
Use chemicals only for the intended purposes.
CAUTION: Consult the instructor before using an unfamiliar product.


Parts-washing solvent (aqueous based)
Aqueous-based parts-washing solvent is used for the same purposes as the petroleum-based solvents, but it is typically nonflammable and contains less than 5% VOCs. Besides water, the ingredients in aqueous-based solvents generally include a detergent, corrosive substance, or alkaline agent and a rust inhibitor. Rather than dissolving grease and solids with chemicals, aqueous solvents use heat, agitation, and detergents to clean automotive parts.

Special cleaning equipment is required that heats the aqueous solvent and sprays it with great force. Spray cabinets, which are totally enclosed, are best for cleaning heavily soiled parts or a large number of parts. Sink-top units are used for more lightly soiled parts or fewer parts.

The life of the solvent can be prolonged by using filters, maintaining the solvent's concentration, and skimming grease from the solution. Aqueous solvent may become hazardous waste through use. Waste disposal professionals must analyze the solution to determine how to dispose of it safely


Types and Uses of Solvents
Parts-washing solvent (petroleum-based)

Petroleum-based parts-washing solvent dissolves oil, grease, and varnish from engine components and other parts of the vehicle. It is usually dispensed in a parts-washing tank that filters and recycles the solvent.

This solvent contains volatile organic compounds (VOCs) that give off toxic vapors and must be managed as a hazardous waste. Parts-washing solvent is not as flammable as some other solvents, but can burn and does present a fire hazard. Keep electrical devices, sparks, and any hot material away from the parts-washing tank. The solvent tank should be equipped with a safety link, which will melt should the solvent ignite. When the safety link melts, the lid on the washer tank will close and smother the fire.

Parts-washing solvent presents a hazard to the eyes and skin, especially when the solvent is fresh. Breathing solvent vapors is also a health risk. Wear personal protective equipment (PPE) when working with the solvent.

CAUTION: Some technicians may have a severe allergic reaction to the parts-washing solvent.

Petroleum-based parts-washing solvent can melt some shoe rubber and should never be splashed or poured on the shop floor. If a solvent spill is not immediately wiped up from the floor, it can cause people to slip and fall. Never put units such as electric motors in the solvent tank. Such units may sustain insulation damage; they may also be hard to dry on the inside. To extend the usable life of the solvent and to prevent clogging the tank, remove most of the grease, gasket material, and dirt from parts before washing. Never pour other liquids into the solvent tank.



Choke and throttle body cleaner
Choke and throttle body cleaner is an aerosol product that is more aggressive than parts-washing solvent in cleaning oil, grease, and varnish from carburetor components and other small precision-machined parts. It is a petroleum-based product.

Choke and throttle body cleaner is extremely flammable and presents a dangerous fire hazard. Never spray the cleaner on hot engine parts or around sparks or fire. The cleaner can also damage paint. Do not spray the cleaner near the body of the vehicle or other painted components. Choke and throttle body cleaner can damage eyes and irritate skin. Breathing its vapors is also hazardous. Always wear PPE and spray the cleaner away from the body so that vapors are not inhaled and the cleaner does not contact the skin. Observe the safety warnings on the cleaner can. Do not expose the cleaner can to heat under any circumstances because heat will cause the cleaner can to explode.



Gasket remover
Gasket remover is an aerosol product that loosens gasket material that may be tightly stuck to engine components with sealers or glue. Gasket remover is extremely flammable and presents a serious fire hazard because the gasket cleaner is sprayed from an aerosol can. Gasket remover can damage paint. Do not spray the remover near the body of the vehicle or other painted components. Gasket remover can damage eyes and irritate skin. Breathing its vapors is also hazardous. Always wear PPE and spray the cleaner away from the body so that vapors are not inhaled and the cleaner does not contact the skin. Observe the safety warnings on the gasket remover can. Do not store gasket remover in a hot area. Do not expose the can to heat under any circumstances because heat will cause the gasket remover can to explode.



Brake cleaner
Brake cleaner is an aerosol product that is extremely effective in removing grease and oil from brake drums, rotors, and engine flywheels. Brake cleaner is extremely flammable and presents a severe fire hazard because the cleaner is sprayed from an aerosol can. Brake cleaner can damage paint. Do not spray the cleaner near the body of the vehicle or other painted components. Brake cleaner can damage eyes and irritate skin. Breathing its vapors is also hazardous. Always wear PPE and spray the cleaner away from the body so that vapors are not inhaled and the cleaner does not contact the skin. Observe the safety warnings on the cleaner can. Do not store brake cleaner in a hot area. Do not expose the can to heat under any circumstances because heat will cause the cleaner can to explode


Gasoline
Gasoline is intended for use as a fuel, not as a cleaner for automotive parts. Do not use gasoline as a solvent.

CAUTION: Never use gasoline or other chemicals for purposes other than those listed on the product can or container. Consult with the instructor before using any solvent or chemical.

Gasoline fumes can cause similar health problems as cleaning solvents and contribute to hydrocarbon emissions. The fumes are also extremely flammable and, if ignited, can cause severe burns or death. Prolonged exposure to liquid gasoline has been shown to cause cancer in laboratory animals. Gasoline additives can leave harmful deposits on important engine components.

Digestive-type carburetor cleaner
Digestive-type carburetor cleaner is an aggressive chemical agent that is usually stored in a 1- or 5-gallon container. The chemical dissolves organic material, leaving only clean metal that is then rinsed with water. Digestive-type carburetor cleaner reacts vigorously with organic material. It presents severe hazards to the eyes and skin. Always wear PPE. Do not splash digestive-type carburetor cleaner.

CAUTION: Digestive-type carburetor cleaner will quickly burn skin that it contacts, so flush afflicted areas immediately with water.

To clean parts, gently submerge the basket of parts into the can. When the solvent has finished cleaning, carry the basket with its lid in place to the sink. The basket of clean parts should be placed in the sink and the parts rinsed in a gentle stream of water. Any spills must be cleaned up immediately. Rags or towels used in the cleanup should be discarded.

Because digestive-type cleaner reacts with organic and some nonorganic substances, use it only on metallic parts. Parts made of rubber, fiber, or plastic may be ruined by digestive-type carburetor cleaner. The cleaner may even remove anodized coatings along with paint and varnish. Never use any of these chemicals for purposes other than those listed on the product can or container.

To keep fumes and evaporation to a minimum, add a 1-in layer of water on top of the cleaner and cover the can with a lid. Digestive-type carburetor cleaner is an expensive chemical and should be used only to clean small precision components. Larger components can be cleaned with other solvents.

Types and Uses of Soaps and Cleaning Solutions
Soaps and cleaning solutions are water-soluble agents used for cleaning dirt and grease.

Liquid detergent, or dishwashing liquid, is a mild detergent that is convenient to use. Liquid detergent is suitable for washing engine blocks after honing or glaze breaking.

Glass cleaner and windshield washer fluid are available in aerosol, pump spray, or liquid form. The best results are obtained when glass cleaner is used with paper towels rather than shop towels. Shop towels almost always retain grease and leave lint.

CAUTION: When filling the windshield washer fluid reservoir in the winter time, read the label on the solution to see if it contains the necessary antifreeze. Freezing can result in a cracked reservoir tank due to expansion.

Hand soaps that are typically used contain an abrasive to help clean ground-in grease. These soaps can cause rawness or cracking of the skin.

CAUTION: Never use abrasive hand soaps on vehicle finishes or plastics because scratches can occur.

Hand-cleaning creams are more effective than ordinary hand soaps on grease and dirt. Hand-cleaning creams are also available with abrasives for tough cleaning jobs. These can be used in conjunction with hand soaps. Hand-protecting creams that are applied before work are effective in preventing dirt and grease from staining the hands and arms. Use of ordinary hand soap will remove the hand-protecting cream.


Cleaning shop floors
According to EPA guidelines, shop workers should keep the shop floor as dry as possible to minimize the amount of wastewater that is generated. Ways to keep the floor dry and clean include the following:

Keep spills off the floor by using dedicated containers for substances like used oil and antifreeze.
Clean up spills immediately to prevent workers from slipping in the substance and tracking it to other areas.
Use rags to clean up small spills and dispose of the soiled rags properly.
Use absorbent pads or mops to clean large spills and wring the substance from the pads or mops into a dedicated container for recycling or disposal.
Use floor sweep (granules that absorb liquids) only when cleaning up hazardous waste spills such as gasoline or solvents.
Sweep the floor with a broom every day to prevent the buildup of dirt and contaminants.
Do not hose down the floor with water or dump mop water because the contaminants will go into the storm drain or sewer, causing pollution.
Use water, a mop, and a mild detergent only if necessary after the spill has been removed. Check with local authorities for the proper disposal procedure.



Specialty cleaning agents
There are many specialty cleaning agents that may be used in automotive technology. As with all chemicals, follow the manufacturer's recommendations and only use the cleaners for their intended purpose. Some examples include the following:

Spot remover
Bug and tar remover
Upholstery cleaner
Carpet cleaner
Vinyl cleaner and conditioner
Battery cleaner
Wire wheel cleaner
White sidewall cleaner



Cleaning shop floors
According to EPA guidelines, shop workers should keep the shop floor as dry as possible to minimize the amount of wastewater that is generated. Ways to keep the floor dry and clean include the following:

Keep spills off the floor by using dedicated containers for substances like used oil and antifreeze.
Clean up spills immediately to prevent workers from slipping in the substance and tracking it to other areas.
Use rags to clean up small spills and dispose of the soiled rags properly.
Use absorbent pads or mops to clean large spills and wring the substance from the pads or mops into a dedicated container for recycling or disposal.
Use floor sweep (granules that absorb liquids) only when cleaning up hazardous waste spills such as gasoline or solvents.
Sweep the floor with a broom every day to prevent the buildup of dirt and contaminants.
Do not hose down the floor with water or dump mop water because the contaminants will go into the storm drain or sewer, causing pollution.
Use water, a mop, and a mild detergent only if necessary after the spill has been removed. Check with local authorities for the proper disposal procedure.