Mixing and storing
paints, solvents, and other coating products is an important part
of routine operations in a collision repair shop. If done properly,
your shop will operate efficiently, safely, and profitably. If not
done right, it can result in higher costs, lower productivity, and
unwanted environmental emissions.
When you open
and mix coating products, you are exposing flammable and potentially
harmful materials to the environment and are increasing the risk
of a fire. Mixing the wrong chemicals can result in wasted material,
and in some cases, pressure build up, heat generations, explosions,
fire, and harmful gases. For example, if you don't use the proper
mixing ratios when preparing a primer or topcoat, your resulting
paint job will be of poor quality, wasting both your time and the
expensive materials used.
steps will help ensure your mixing operations are being operated
Before opening containers, check for sources of ignition such as
open flames, cigarettes, spark producing tools, welding torches.
Check to make sure the ventilation system in the mixing rooms is
functioning properly so that explosive vapours cannot build up.
Before transferring flammable liquids, make sure that grounding
or bonding wires are attached.
Before mixing, read the manufacturers' MSDS, product labels, or
technical product bulletins to become familiar with the mixing instructions,
and to know what materials can be safely mixed together, and what
personal protective equipment is recommended.
Wear all personal protective equipment recommended on the supplier
Whenever possible mix colours in house. When required, stir colours
for the required time before mixing. This will minimize poor colour
matches and wasted material.
For mixing colours, consult manufacturers' formulations typically
found in a computer database. Use a 'smart scale' or computerized
digital balance to ensure proper weighing of materials. Most systems
provided by paint suppliers can make corrections to improperly mixed
colours by automatic re-calibration. Check with your paint supplier
for more details.
Mix only the amount of coating product that you will need for the
job to avoid waste. Computerized mixing scales permits smaller,
accurate preparation of colour formulations.
Make sure the colour formulation is the best match for the shade
of the specific colour. Some coating suppliers provide alternate
or variant formulations for a specific colour.
Before painting the vehicle, spray a small test panel to ensure
you have the proper colour match to avoid a possible re-do, and
wasted time and materials.
Avoid the use of high solvent coatings such as lacquers. Use low
VOC coatings such as waterborne or high solids.
Apply the minimum number of coats for good colour match and hiding.
Ask your paint supplier about the use of tinted primers to reduce
the amount of topcoat needed.
Keep all containers closed, replace lids immediately to prevent
vapours from entering the environment.
Manage your paint inventory wisely to avoid the high costs of disposing
of 'stale dated' products. Use paint on a 'first in, first out'
Store hazardous wastes in properly labeled, impermeable containers
with adequate spill containment.
Clean up leaks and small spills immediately
for the Paint Mixing Room http://concessions.nps.gov/document/paintmix.pdf