Intercoastal Paint Company

Waterborne Fast Dry Shop Primers

Table of Contents


1. Waterborne Shop Primers - Why use them?

2. VOC Calculations

3. How Waterborne Primers Dry

4. Properties of Intercoastal Paint’s Waterborne Shop Primers

5. Bulletin I Handling Intercoastal Paint's Fast Dry Waterborne Products

6. Bulletin II Painting in bad weather conditions using Intercoastal Paint’s
    Fast Dry Waterborne Primers

7. Bulletin III Spray Equipment Cleaning Procedures:
    Changing from solvent based primers to water based primers

8. Bulletin IV Surface Preparation

9. Bulk Tank Agitation Set Up

10. Product Specification - WP-1009 Brown Oxide Fast Dry Waterborne
      Primers



 

Waterborne industrial primers are being used more frequently today due primarily to increasing environmental regulations. The issue here is the amount of solvent, or VOC, that is released into the atmosphere when the coating is applied. "VOC" stands for "Volatile Organic Compounds". These emissions are usually expressed in pounds of VOC per gallon of paint. See VOC calculations on the following page. Below are some examples of typical VOC levels.

1. Conventional solvent borne 4.0-4.5 lbs/gal VOC

      ready to spray shop primer

2. High solids solvent borne 2.8-3.5 lbs/gal VOC

     shop primer

3. Intercoastal Paint WP-1009 .33 lbs/gal VOC

    waterborne shop primer

Shop primers for structural steel in the metal building industry are usually required to have a VOC of 3.5 lbs/gal or less in areas where air quality is an issue.

Other reasons for using waterborne primers include fire and health issues. Intercoastal Paint’s waterborne primers are non-flammable. The Fire Marshall and fire insurance underwriters both look favorably upon waterborne coatings.  Likewise, lower levels of organic vapors in the work place are a plus from a health standpoint.

Finally is the reason of quality of the coating. Properly applied and cured films of waterborne shop primers can equal or even surpass the real world performance of solventborne counterparts. Intercoastal’s waterborne primers do not fade like solventborne high solids primers. They exhibit good adhesion to a wide variety of substrates, such as galvanized steel or aluminum. They accept finish coats of many types such as alkyds, other latexes, lacquers, two part epoxies and two part polyurethanes. These primers are more versatile as universal primers than their solventborne counterparts.

Method I:  "As applied" or "As packaged"

This is the weight of solvent in 1 gallon of paint. (This is the actual amount emissions in one gallon of paint).

Example divide the weight of solvent by the volume of paint.

(Here, we are using 100 gallon formula)

VOC I = 33.20 lbs solvent

100 gallons of paint = .332 lbs/gallon

Method II:  "Less water" 

This is the weight of solvent in 1 gallon of paint minus the volume of water in 1 gallon of paint. (This method is sometimes required by the EPA).

Example divide the weight of solvent by the volume of paint minus the volume of water.

VOC II = 33.20 lbs solvent

100 gallons - 62.40 gallons = .883 lbs/gallon water

Method III:  "Per applied solid gallon" 

This is the weight of the solvent in 1 gallon of paint minus the volume of water and the volume of solvent in 1 gallon of paint. 

(This method was discontinued by TNRCC in February 1996).

Example divide the weight of solvent by the volume solids of the paint

VOC III = 33.20 lbs solvent

33.06 gallons (volume solids) = 1.004 lbs/gallon

Conversion Factors (all methods):

To convert lbs/gal to kg/1; multiply by .1199

To convert kg/1 to lbs/gal; multiply by 8.327

*Waterborne primer used as example WP-1009

33.06% volume solids

62.40 gallons water per 100 gallons

33.20 pounds VOC per 100 gallons

3. How Waterborne Primers Dry

1. Before the primer is applied, the liquid paint contains individual particles of resin called micelles. These are suspended in a water medium by emulsification.

2. When the primer is applied and the water begins to evaporate, the resin particles begin to collect on the surface of the steel.

3. As the last of the water leaves, the particles melt together to form a continuous film. The small amount of solvent (VOC) is what primarily melts the particles.

If the water stays in the film longer than the solvent, these particles do not melt together properly. This results in an inferior film. The most common causes are high humidity and/or low temperature. The simple act of spraying waterborne shop primers can sharply raise the humidity in the spray booth.

Intercoastal Paint’s waterborne shop primers are unique because they dry in high humidity and low temperature conditions.  When comparing the dry times of waterborne shop primers from several vendors, we strongly suggest that the comparisons be made side by side at the same time under the same conditions (humidity and temperature) and the same mil thickness, etc. We feel confident that the comparison will demonstrate that Intercoastal Paint has the fastest dry time by far.

1. Dry Time:  From a production standpoint, dry time is the most important property. Many waterborne primers will dry satisfactorily in warm weather. However, when the temperature drops and the humidity rises, they stop drying or slow down enough to result in an unsatisfactory paint job.  Intercoastal Paint’s waterborne primer will produce good films under these same conditions.

2. Sag Resistance:  Generally, airless application will result in 5-6 wet mils of paint per pass. This can potentially be doubled at the intersection of two welded pieces because of overlapping. In adverse weather conditions, these heavy films can sag and run, resulting in uneven coverage and an unsightly paint job. Intercoastal Paint’s waterborne primers perform well under these conditions, producing a consistent and even film without sags, runs, or "curtains".

3. Early Water Resistance:  This is an important property because occasionally rain water will collect in the web of the beam while the steel is on the truck or at the job site. Intercoastal Paint’s waterborne primers are designed to exhibit good early water resistance to minimize water damage or water marking.

4. Color:  Our brown oxide waterborne primer, WP-1009, matches the color of MBCI coil steel. Every batch of primer is checked for color, and the batch to batch color consistency is excellent.

5. Weather Ability:  All Intercoastal Paint’s waterborne primers are exposed to the weather at 45º South on our test fence. We have data on the bare primers exposed for 24 months without serious rusting or other film deterioration.  This real world testing is a better measure of weathering than accelerated testing methods.

6. Quality Control:  Each batch of Intercoastal Paint’s waterborne primers must pass 8 quality control assessments before it can be shipped. A complete record is kept of the batch number and test results as well as a sample from each batch.  We can retrieve quality control information and samples of batches that were produced years previously.

Intercoastal Paint's Fast Dry waterborne coatings are made using a special polymer, which allows them to dry rapidly and to dry under adverse weather conditions such as high humidity and/or low temperature.  Since the binder is rapid drying, the paint can actually be made to set up in the container or application equipment before it is applied. To avoid this gellation, some simple precaution can be taken.

1. AVOID CONTACT WITH REACTIVE METALS

All spray equipment that comes into contact with these products must be made of

non-reactive metals (stainless steel or chrome), or of plastic. Continuous contact

with mild steel, galvanized steel, or other reactive metals in pressure pots, cups,

agitators, pumps, hoses, lines, filters or spray guns can cause the paint to dry on

the part, which can eventually lead to malfunction.

2. KEEP CONTAINERS COVERED

Excessive exposure to air can set off the drying mechanism in these paints. The

higher the temperature, the more important this becomes.

3. STIR PAINT SLOWLY- DO NOT OVER AGITATE IT

These products only require mild stirring. Rapid agitation with mechanical

agitators can heat up the paint and can cause air entrapment. This can cause

gellation. Usually sweep blade agitators turning 50-60 RPM are ideal.

Propeller type blades can whip air into the paint when the container is nearly empty.

4. DO NOT THIN PAINT

These products are formulated ready to spray as is. Improper thinning can cause

development of gel particles or "trash" in the paint.

5. KEEP EQUIPMENT CLEAN

When not painting for an extended period of time, flush the application

equipment with clean water. For breaks of shorter duration, place the spray gun

in a container of water. This prevents the paint from drying in the tip.

6. STORE PAINT IN A COOL PLACE

Obviously, this is not always practical. When possible, avoid storing the paint

outside in 100 degree summer heat. Likewise, keep the paint from freezing in

the winter.

6. Bulletin II:  Painting in Bad Weather Conditions Using Intercoastal's Fast Dry Waterborne Primers

Intercoastal Paint’s fast dry waterborne primers are made using a special polymer which allows them to dry rapidly and to dry under adverse weather conditions such as high humidity and/or low temperatures.  However, some precautions should be taken when the winter conditions become severe at either the plant site where the paint is applied or the building site.  Below are some suggestions which can help prevent problems caused by the weather.

1. PROTECT FROM FREEZING

Store tanks or drums inside and away from freezing weather.

2. MAKE CERTAIN STEEL IS DRY BEFORE PAINTING

When the humidity rises rapidly, the steel surface can "sweat", which is the condensation of moisture from the air onto the steel surface. If the surface is wet when the primer is applied, the drying will be much slower, and adhesion and rust problems can occur.

3. APPLY PRIMER TO STEEL ONLY WHEN SURFACE TEMPERATURE IS ABOVE 50 DEGREES FAHRENHEIT

This is not always easy to do in the winter time. If the steel is cold, the dry time and the cure time will be lengthened.

4. CIRCULATE THE AIR AROUND FRESHLY PAINTED STEEL

When the weather gets cold and damp, all of the shop doors and windows are usually closed. As more waterborne primer is sprayed, the humidity in the building rises sharply, slowing the dry and the cure. Strong pedestal fans (3500RPM) will help this problem considerably.

5. APPLY ONLY 1½-2 MILS (DRY) OF PRIMER

Thicker films are slower to dry and cure. If ice is allowed to form on the painted steel before the film is cured, loss of adhesion can occur.

7. Bulletin III Spray Equipment Cleaning Procedures:  Changing from Solvent Based Primes to Water Based Primers

Waterborne coatings are not compatible with conventional solventborne coatings, therefore care must be taking to properly clean application equipment and avoid contaminations. When changing from solvent to water, all hoses, spray guns, and other equipment must be cleaned as follows:

1. Thorough solvent wash

2. Flush well with isopropyl alcohol or butyl cellosolve

3. Flush well again with water

When changing from water to solvent, reverse the procedure.

When it comes to surface contamination, water based coatings are usually less forgiving than solvent based coatings.  However, it is not difficult to properly prepare steel (or other substrates) for painting with Intercoastal Paint’s waterborne shop primers. A few simple steps are all that is required.

1. Degreasing: Any cutting oil or other greasy or oily substances should be removed from the surface before painting.  This can be done easily with a degeaser.  If environmental issues prevent the use of solvents, a VOC compliant degreaser such as Simple Green can be used.  This product is VOC free and totally biodegradable.  Usually one part of Simple Green reduced with ten parts of water is effective. The oily areas can be wiped clean and without residue with a rag saturated with this mixture.

2. Cleaning: Hand tool cleaning according to the Surface Preparation Specification No. 2 (SSPC- SP2) is all that is required.  Painting over rust and other surface contaminants can result in an unsatisfactory paint job.

3. Drying: Occasionally, on days with high humidity, the steel will "sweat" as water condenses on the surface.  Painting over wet steel can retard the dry process as well as prevent good adhesion.  A simple wipe down with a clean rag is usually all that is required.

9. Bulk Tank Agitation Set Up

10.  Product Specification - WP-1009 Brown Oxide Fast Dry Waterborne Primers

Date: February 26, 2002

Thinner:  Airless Thinner

The recommendations made herewith and the information set forth with respect to the performance or use of our products are based on our own research and are believed to be accurate.  The products discussed are sold without warranty, as to fitness of performance, expressed or implied, and upon condition that purchasers shall make their own tests to determine the suitability of such products for their particular purposes.  Likewise, statements concerning the possible uses of our products are not intended as recommendations to use our products in the infringement of any patent.