Chemical Dip Tanks Safety Program

Chapter Section

Introduction/Overview

A dip tank is a container that holds a liquid, other than plain water, in which objects are completely or partially immersed for dipping or coating. Objects may also be suspended in the vapor above the liquid inside the tank. The general term “dipping and coating” covers a wide variety of workplaces and operations.

Use of Dip Tanks

Dip tanks are used in a wide variety of industries and workplace operations; however, their use can generally be put into one of four categories.

• Cleaning objects. For example, grease and oils might be cleaned off metal materials by dipping into solvent liquids, solvent vapors, sodium hydroxide solutions, and even water based soap solutions.
• Coating objects. Paints, waxes, plastics, and other coatings can be applied by dipping an object into the tank.
• Surface alteration. Chemicals in dip tanks can also be used to alter the surface of an object. Acid tanks are often used to etch metal materials in order to make them thinner.
• Changing the character of an object. The character of metal materials can be changed in dip tanks through processes such as electroplating.

TYPICAL DIP TANK OPERATIONS

• Paint dipping—applying paint by dipping objects into a tank of paint
• Electroplating—a process in which an object is coated with metal
• Pickling—dipping foods into a brine solution or dipping metal parts into an acid solution
• Quenching—dipping hot materials into a tank for immediate cooling
• Tanning—a process used to convert hides or skin into leather
• Degreasing—cleaning oily and greasy metal parts by dipping them into solvent liquid or vapor
• Stripping—refers to a number of different processes such as dipping furniture into a chemical in order to strip old paint off the wood so it can be refinished with a new paint or other coating
• Cleaning—an operation found in many different industries that can include dip tanks of solvent, alkaline solutions, or even soap and water solutions
• Dyeing—dipping an object into a tank of dye to change its color
• Roll, flow, or curtain coating—different ways to coat objects with materials such as plastics, waxes, paints, etc.