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Factors Involved In Spraying Waterproof Coatings


Applying waterproof coatings can protect your home or business from water damage and extend the life of your roof, walls, and other surfaces. When spraying waterproof coatings, there are several key factors you need to keep in mind for optimal results. In this article, we will discuss critical considerations when using an airless sprayer to apply waterproof sealants.


Choosing the Right Waterproof Coating


There are many types of waterproof coatings, including acrylic, polyurethane, epoxy and rubberized asphalt. Consider factors like the surface type, exposure to weather/sunlight, durability needed and budget. For example, acrylic latex coatings are user-friendly and low cost but less durable than polyurethane or epoxy which are extremely durable but higher in VOC content.


Acrylic Coatings


Acrylic waterproof coatings contain acrylic resins that form a protective barrier against water.  They come in solvent-based and water-based options.  Acrylic coatings are flexible, allowing for small cracks.  They adhere well to many surfaces like concrete, masonry, wood, and metal.  Acrylics work for indoor and outdoor use.  They resist weathering and UV exposure.  Solvent-based acrylics provide better water resistance compared to water-based.  However, water-based acrylics contain lower VOCs.


Epoxy Coatings


Epoxy coatings contain epoxy resins mixed with a polyamine hardener.  They cure to form a rigid, protective barrier ideal for concrete and metal.  Epoxy coatings offer excellent adhesion and water resistance.  They withstand chemical exposure well.  Epoxies are more difficult to apply than acrylics.  But their durability and impermeability make them worthwhile for damp, chemically-exposed industrial environments.


Polyurethane Coatings


Polyurethane coatings contain isocyanates that form flexible polymer chains upon curing.  Polyurethane effectively seals surfaces and joints while allowing some flexibility.  It adheres well to wood, concrete, fiberglass, and metal.  Polyurethane coatings resist abrasion and corrosion.  They work for high-traffic areas both indoors and out.  Polyurethane coats evenly and dries faster than epoxy.  However, it can be difficult to apply in cold temperatures.  Proper ventilation is critical when applying.


Surface Preparation

Proper surface preparation is essential prior to applying any coating. All surfaces should be clean, dry and free of loose material, dirt, grease, oil and other contaminants that can prevent proper adhesion. Concrete and masonry should be fully cured. Any cracks, holes or imperfections should be patched and smoothed. Metal surfaces may need to be sanded or abraded to improve adhesion. Proper prep work will allow for maximum bonding between the coating and surface.


Applying the Proper Film Thickness  

Waterproof coatings must be applied at the thickness specified by the manufacturer to function correctly. This is usually measured in mils - with 1 mil equaling one thousandth of an inch thickness. Insufficient thickness can lead to leaks or early failure. Excessive thickness can cause drying problems or result in the coating cracking or peeling. Applying too much coating at once can also lead to runs and sags. Use a wet film thickness gauge while spraying to monitor thickness. Adhere closely to the coating's recommended coverage rate per gallon to achieve the proper film build.


Checking for Pinholes

Pinholes are small holes in the coating that allow moisture to penetrate. These are caused by air bubbles or off-gassing from the underlying surface. It's critical to check for pinholes or holidays after spraying the first coat. Adding more coats will not fill these voids properly. Pinholes can be repaired by hand brushing additional coating to fill and seal them off. Allow proper drying time between coats as specified by the AEROPRO.


Weather Conditions

Ideally, waterproof coatings should only be applied in dry conditions when temperatures are above 50°F. Colder temperatures can inhibit proper curing and adhesion. High humidity will also prevent coatings from drying effectively. The surface should be dry before applying the coating. Rain or dew can ruin the coating after sprayed, pay close attention to weather forecasts.


Ventilating the Area

Most waterproof coatings contain VOCs that necessitate proper ventilation during and after application. This is especially important in confined indoor areas. Open windows and use fans to circulate fresh air. Negative air flow devices may also be needed. Wearing a respirator is advisable to avoid inhaling VOCs while spraying. Ensure the coating has fully off-gassed before the area is reoccupied.


In the face of spraying waterproof coatings, give your projects an expert finish and maximize productivity with the new AEROPRO 650 airless sprayer. It has 4HP power motor, get more work done. Durable filtration, easy out filter provides easy maintenance and less clogging. Low MoCr2 independent steel bushing, super wear-resistant, easy to clean!


Low per minute 2000 unique inductive intelligent recognition nozzle technology. The biggest can support 633 nozzles, improve construction efficiency. Robust all-metal construction withstands heavy duty use on worksites while the convenient cart design allows effortless mobility. 

Fit for wall emulsion paint, coating, colorants, steel structure anticorrosion paint, epoxy Paint, enamel paint on the metal surface. Built for professional remodeling and repainting contractors looking to increase the number of larger jobs.



Motor size:4HP(3000W)

Max pressure:3300PSI(227bar)

Standard Noozle size:625(0.025")

Flow rate:5L/min(1.35GPM)

Max.Pressure for the hose/Length:83Mpa

Length of High Pressure Hose:30m

Max spray tip:633


AEROPRO has quickly risen to become an unrivaled global producer of air-powered devices including air tools, air spray gunair nailer, airless paint sprayer, and etc.

AEROPRO seeks independent sales agent to represent and market our industry-leading pneumatic tools. We support OEM, ODM, OBM customization, small order quantity is acceptable and samples are available.

Make any cooperation possible. Any services related to the product, inquire with us now! Sales@Aeroprotools.Com