PREDICT THE THICKNESS OF PAINT
November 21, 2014
Categories: Coating Solutions, News, Paint Audit, Paint Knowledge
It is easy to predict the thickness of paint after it dries. All that is required is that you know the “percentage of volume-solids” of the paint and that you have a “wet-film-thickness gauge”. The paint’s volume-solids (not to be confused with “weight-solids”) is listed on the Product Data Sheet, which can be found on the paint manufacturer’s website. A “wet-film-thickness” (WFT) can be purchased at professional paint stores or online, or obtained Free from Carbit.
In previous articles I discussed “paint volume solids”, which I described as “what’s left after the paint dries”. In that article I explained that as paint dries it shrinks in direct proportion to its volume solids. For example, a paint with 50% volume solids will lose one-half of its volume as it dries. If it is 4 mils when wet it will be 2 mils thick (4 x 50%) when dry. Paint Volume Solids Fortunately, the
Wet-Film-Thickness (WFT) of a coating can be easily measured with a Wet-Film-Thickness Gauge.
To use a WFT Gauge you depress the graduated edge of the gauge into the layer of wet paint immediately after it has been applied. Withdraw vertically and note deepest tooth having paint on it and the next higher tooth that is not coated with paint. The true wet film thickness lies between these two readings.
In the U.S. the thickness of paint is expressed in mils (one mil equals 1/1000 of inch). The rest of the world expresses coating thickness in microns (1 micron = 1 millionth of a meter and 25.4 microns = .001” inch or 1 mil). The table below compares the thickness of common materials in mils and microns.
Being able to predict the thickness of paint has many practical benefits:
- It ensures that you are applying the correct amount of paint to achieve the performance properties of the coating.
- Coating thickness correlates to dry-time, recoat time and appearance.
- And, the ability to predict the thickness of paint helps you control cost.
For more information or help to predict the thickness of paint that you are applying complete our “get-in-touch” form below or call us at 312-280-2300. Bob Lyons – Carbit Paint Company, LLC – November 2004
Paint Audits Prevent Problems
July 11, 2014
Categories: News, Paint Audit, Paint Problem, Uncategorized
A quick paint audit can keep you from getting caught by the cold.
Each fall we get numerous calls asking, “Have you changed the paint?” The caller often explains that the paint isn’t drying it like it use to. We are always happy to check our batch samples to be sure that nothing had accidentally changed but the answer to the problem usually relates to one of two factors:
- A change in application conditions – temperature and humidity, or;
- A change in the application procedure that creates greater film thickness or slower drying times. Factors are larger spray tips and/or higher pressures that cause heavier film builds, or faster conveyor or line speeds that allow less time for the wet paint to cure.
Now is the time to conduct an audit to prevent getting surprised when the weather changes. We will identify the critical steps in your finishing process and set quality assurance standards for each.
- Surface preparation –cleaning, profile, etc.
- Equipment set up – tip/nozzle, air/fluid pressure, etc.
- Paint preparation – mixing/thinning, viscosity
- Application – spray technique – edging, spot-priming, etc.
- Application rate – wet-film-thickness/ dry-film-thickness
- Drying/curing requirements and conditions
- Handling/assembly or pack-out procedures
It’s a good practice to have a paint audit conducted annually or whenever there is a significant change in the materials, procedures , workers or weather. Carbit’s experienced Project Managers perform free paint audits as a way to introduce ourselves and as a service to help you preempt problems before they occur.
Written by Bob Lyons, Carbit Business Development
Download printable version: Paint Audit_News