Understanding Volume Solids provides many benefits:
It allows one
* to compare the true cost of different paints.
* to predict how much paint must be applied to obtain adequate coverage.
* to control the quality of the paint job.
* to avoid production delays
Paint = pigment + resin (binder) + vehicle (thinner or mixture of solvents) + additives.
The pigment and binder form the volume solids of the dry paint film after the vehicle and some additives evaporate.
The volume solids = matter left after the paint dries
The typical volume solids = 30 – 45% of the paint volume.
Thinning a paint reduces the volume solids.
The volume solids of a paint allows one to use a WFT (wet-film-thickness) Gauge to predict the DFT (dry-film-thickness) of paint.
DFT =WFT x VS
The thickness of paint after it has dried can be measured using a Dry-Film-Thickness gauge.
Let us assume the volume solids of a paint is 43% (contributed by paint and resin). The wet film thickness is 152.4 microns (6 mils). After curing it forms a dry film on the substrate to 65.5 microns.
Paint cost varies with volume solids. Negotiate with your customer for an optimum DFT and insist your paint supplier on desired volume solids.
It is always a good practice to measure both WFT and DFT so that one can check the volume solid of the supplied paint.
For further training on cost control of painting and paint, please contact the consultant in https://t.me/saitechinfo