![[EAH INDUSTRIAL]](https://data3.answerbase.com/answerbase/14455/Images/answerbase.brands.header3 (1).png?638469925900000000)
Answer
This question has not yet been answered.
"Are You Unknowingly Sabotaging Your Green Reputation? 🌱" American Turbine Hvlp Sprayers - Complete Units
Low VOC Coatings: Controlling Viscosity and Spray Equipment and Their Relationship
A Detailed Breakdown for Bathtub, Tile, and Countertop Refinishers
Introduction:
As the bathtub, tile, and countertop refinishing industry evolves, so do the products and tools professionals use. One of the most significant changes in recent years has been the shift towards low VOC (Volatile Organic Compounds) coatings due to stringent environmental regulations. While these products offer environmental benefits, they also present new challenges, particularly in how they interact with spray equipment like turbine HVLP (High Volume Low Pressure) sprayers. Understanding the relationship between low VOC coatings, their viscosity, and the capabilities of spray equipment is crucial for refinishing professionals to achieve optimal results without compromising the integrity of the coatings.
Understanding VOCs and Their Impact
What are VOCs?
VOCs are chemicals that evaporate at room temperature and contribute to air pollution. In the context of coatings, VOCs are primarily found in the solvents used to thin the paint or coating for application. Low solid, high VOC coatings contain more solvents, which evaporate into the atmosphere, contributing to pollution.
Transition to Low VOC Coatings
Historically, coatings used in the refinishing industry had solid contents ranging from 35% to 45%. This meant that up to 65% of the product was liquid solvent, which would evaporate during drying, releasing VOCs into the environment. This means low solid coatings are not environmentally friendly.With the push towards greener practices, many states have mandated the use of low VOC coatings, which contain higher solid content—typically between 72% and 87%—and less solvent. The result is less evaporation and a reduced environmental impact.
The Relationship Between Viscosity and VOC Content
High Solid, Low VOC Coatings
With low VOC coatings, the reduced solvent content results in a higher concentration of solids. This makes the coating thicker or more viscous. Viscosity refers to the thickness or resistance to flow in a liquid. High viscosity in coatings can make them more challenging to spray, especially with equipment not designed to handle such thick materials.
Low Solid, High VOC Coatings
In contrast, coatings with higher VOC content have more solvent, making them thinner and easier to spray. This lower viscosity means that older or less powerful equipment, like 2- or 3-stage turbine HVLP sprayers, can atomize the coating more effectively.
Spray Equipment:
The Evolution of Turbine HVLP Sprayers
Turbine HVLP sprayers are popular in the refinishing industry due to their efficiency in applying coatings with minimal overspray and waste. These sprayers use air generated by a turbine to atomize the paint. The number of stages in a turbine refers to the number of fans in the turbine, with each stage increasing the pressure and air volume.
Why 2-3-4 Stage Turbines Fall Short
When using high solid, low VOC coatings, the increased viscosity means that more pressure and airflow are required to atomize the paint properly. A 2- or 3-stage turbine, which might have been sufficient for lower viscosity, low solid, high VOC coatings, often lacks the necessary power. The result is a coating that may not atomize correctly, leading to poor finish quality.
The Irony:
Unintentionally Compromising Your Green Marketing: The Common Mistake
One of the most ironic and counterproductive practices seen in the bathtub, tile, and countertop industry is the adding of solvents to the low VOC coating mix to make them easier to spray with underpowered equipment.
This practice effectively increases the VOC content of the coating, negating the environmental benefits and potentially compromising the coating’s performance. It’s akin to adding too much liquid to a cake mix—the result may look similar, but it won’t perform as intended.
So, How Much Solvent is Too Much?
The coating as it is sold and received by the refinisher is already low VOC, typically containing fewer than 50 grams per liter (g/L) for flat paints and under 100 g/L for non-flat paints . Adding solvent to make it sprayable with underpowered turbine HVLP sprayers increases the VOCs, potentially pushing it out of low VOC compliance. So, how much is too much?
Let’s break down a few examples:
- Base Mix: 12 ounces of Part A and 3 ounces of Part B, totaling 15 ounces.
Adding 3 Ounces of Reducer:
- Total Mix: 18 ounces.
- Percentage of Reducer Added: 3/15 = 20%.
- Original Solid Content (82%): 12.3 ounces solids.
- The Reduced Solid Content You are Spraying: 12.3/18 = 68.3%. (No Longer VOC Compliant)
Adding 4 Ounces of Reducer:
- Total Mix: 19 ounces.
- Percentage of Reducer Added: 4/15 = 26.7%.
- Original Solid Content (82%): 12.3 ounces solids.
- The Reduced Solid Content You are Spraying: 12.3/19 = 64.7%. (No Longer VOC Compliant)
Adding 5 Ounces of Reducer:
- Total Mix: 20 ounces.
- Percentage of Reducer Added: 5/15 = 33.3%.
- Original Solid Content (82%): 12.3 ounces solids.
- The Reduced Solid Content You are Spraying: 12.3/20 = 61.5%. (No Longer VOC Compliant)
Adding 6 Ounces of Reducer:
- Total Mix: 21 ounces.
- Percentage of Reducer Added: 6/15 = 40%.
- Original Solid Content (82%): 12.3 ounces solids.
- The Reduced Solid Content You are Spraying: 12.3/21 = 58.6%. (No Longer VOC Compliant)
In each case, the more reducer you add, the lower the solid content becomes, thereby reducing the performance characteristics of the coating. For example, if your starting mix has 82% solids, and you add enough reducer to bring it down to 68.3% or lower, you’ve effectively pushed the coating out of the low VOC category and made it non-compliant with most U.S. regulations.
The Benefits of Using Powerful Turbines
Investing in a more powerful turbine, like a 5- or 6-stage model, will not only help you maintain the integrity of low VOC coatings but also deliver a significantly better final product. By avoiding the need to add excessive reducers, you'll achieve a higher mil thickness and a more even application without the issues that come with uneven or excessive solvent evaporation, such as pinholes, bubbles, blushing, and loss of gloss.
Conclusion
The relationship between low VOC coatings, their viscosity, and turbine HVLP sprayers is complex but critical to understand. As the bathtub, tile, and countertop refinishing industry continues to evolve towards greener practices, it’s essential for professionals to invest in the right equipment—like 5- or 6-stage turbines—to ensure that they can apply these coatings effectively without compromising on quality or environmental benefits.
And remember, while it might seem like adding a little extra solvent is just a way to make life easier, it’s a slippery slope. Before you know it, you’ve turned your eco-friendly coating into a VOC soup that not only breaks the rules but also performs like a soggy pancake. So, resist the temptation to take shortcuts—because just like in cooking, too much sauce can ruin the dish!
Question ID: 5144849 Status:
Open Aug 05, 2024 - 02:23 PM
Shark Bites: Dive Deep into Shark Bites: Your Weekly Source for Essential Technical Tips!
Do you have the same question? Follow this Question
Browse by Category
American Turbine Hvlp Sprayers - Complete Units
View our complete selection of American Turbine Hvlp Sprayers - Complete Units to find the one that suites your needs.
View All
View all American Turbine Hvlp Sprayers - Complete Units Questions & Answers
Add New Comment