How to use Vitrocoat industrial glass paint additive

Comprehensive Mixing Instructions For Use

Compatible PU Paints:

Vitrocoat industrial glass paint solution is formulated as an additive to commonly available 2-part polyurethane (2K PU) paints, for use as a color coating system for glass.  While there are many PU paints available, Vitrocoat has been thoroughly tested and used commercially with the following readily available paints in the UAE:

• Interthane 990, Interthane 870 (Akzo Nobel – International Paints)
• Hardtop Series of Paints (Jotun)
• Top Coat (Alva Paints)

Using Vitrocoat Industrial Glass Paint additive with Other Paints:

While no problems are expected using Vitrocoat with other reputable PU paint brands, we strongly recommend customer’s test Vitrocoat with their chosen supplier’s paint. Also please contact us for a list of approved paints in you location.

Basic Mixing Considerations:

PU paints consist of two parts: the base paint and the hardener.

Vitrocoat Ratio: Vitrocoat is mixed with the base paint at a ratio of 1.5% Vitrocoat to paint. So for every 1 liter of paint, add 15 cc (15 ml) of Vitrocoat. This mixture can be stored upto 6 months as long as it is seal properly and the hardener is not added.

• Measuring Vitrocoat: Use small plastic disposable measuring cups or  or measuring syringe to measure Vitrocoat accurately. Measuring syringes can be reused after cleaning with ethyl alcohol.

Mixing and Storage:

Vitrocoat additive itself can be stored for over a year if the bottle is sealed properly and stored in a cool place. Do not leave vitrocoat in direct sunlight.

• Mix Vitrocoat with the base paint 4 hours before use. This mixture of Vitrocoat and base paint can be stored for up to six months in air-conditioned storage without issue, as long as the paint lid is closed properly and hardener is not added.
• Adding The Hardner : Mix the hardener with the paint and Vitrocoat mixture only when ready for application. Mix the hardner in following the paint manufacturer’s instructions.

Spray Painting Considerations

Thinner for Spraying:   For spraying applications, add polyurethane thinner to achieve the desired working viscosity depending on your spraying technique. Typically, 10 to 15% by volume is sufficient.

Moisture Control When Spray Painting:  If you choose to spray paint your glass, it’s crucial to ensure a dry air supply. Here’s what you need to know:

• Water Removal: A standard water trap between the compressor and the spray gun can remove some moisture.
• Best Practice: A condensing air dryer unit is highly recommended for optimal dryness.
• Moisture Condensation: As compressed air escapes the spray gun, a drop in pressure and temperature can cause water to condense on the paint droplets and transfer to your work piece 

Basic Mixing Considerations

PU paints come in two parts, the base paint, and the hardener.   

The Vitrocoat material is mixed with the base paint at a ratio of 1 to 1.5 parts Vitrocoat  to 100 parts paint, i.e. to 1 litre of paint, 10 to 15 cc, (10 to 15ml) should be added.  1% of Vitrocoat by volume is normally sufficient for most PU paints.  The measurement of the Vitrocoat can easily be done with a small measuring funnel, or pipette available from most pharmacies or laboratory supply houses.  The pipette may be cleaned afterwards for re-use, using e.g. Ethyl Alcohol.

Important : Ideally the mixing should be done 4 hours before the paint is to be used.  

Mixing and Storage: The paint in this condition can be kept for up to six months in air conditioned storage without any problem, as long as the hardener is not added.

Mixing the Hardener: The hardener is then mixed with the paint /Vitrocoat mixture according to the manufacturers instructions, ONLY WHEN THE PAINT IS REQUIRED FOR  APPLICATION.

For any further Inquiries on mixing vitrocoat industrial glass paint additive contact us.

Paint application

Glass Temperature for Optimal Results:

• Achieve the best paint results on glass when the temperature is at least 20°C at painting time.

Industrial Application Tips:

• For large-scale glass painting, consider using a warming area to elevate the glass temperature. This helps with drying, though good results are possible without it.

Benefits of Warming Glass:

• Warming the glass isn’t mandatory but helps in achieving even drying and prevents the “skinning” effect where paint forms a skin, trapping solvents underneath.

Temperature and Adhesion:

• Applying paint at low temperatures can reduce adhesion. This issue isn’t unique to Vitrocoat but common in painting non-porous surfaces.

Spray Painting Precautions:

• For spray painting, ensure your air supply is as dry as possible. Use a water trap or, consider investing in a condensing air dryer unit. As air exits the spray gun, it cools and can condense moisture onto paint droplets, potentially affecting your work.

Here are some methods for heating glass panels in colder wet weather before painting without a dedicated glass warmer.

• Space Heater: Caution: Maintain a safe distance between the heater and the glass to avoid cracking.
• Heat Lamp: Similar to a space heater, use caution with positioning to prevent cracking.
• Warm Room: If possible, move the glass panels into a warm, dry room before painting. Aim for a room temperature of at least 20°C (68°F).

Cleaning the Glass:

Cleaning the glass does not require any special treatment other than ensuring that the glass surface is decreased and dry before painting. A pass through a standard washing machine is recommended. It may be advisable to clean with thinner and/or ethyl alcohol before painting.

Paint Application:

The paint application may be made in a number of coats, or a single application as in the case of curtain coating machines, or automatic spraying booths. The colour quality is dependent on the pigment ratio of the paint.

Drying:

While many users achieve perfect results using air drying at room temperatures, the use of an infra-red or hot air dryer will speed up the drying process, using moderate temperature settings. A tunnel dryer set at 60 degrees Celsius at moderate speed will considerably reduce drying time.

• UV curing is not applicable, as the components are not designed to be polymerized by UV light.

Paint Curing:

It should be noted that the PU paint will harden more and more over time, until after a few days, the paint will be difficult to ‘dent’ or scratch and will resist attack even from solvents.

Thinner:

Remember to always use the thinner recommended for PU paint by the paint manufacturer. 10 – 15% by volume should be sufficient for spraying. Recommended Nozzle size for spraying  – 1or 2.

Dust and Application Area: Many users will rightly be concerned about dusty conditions in the workshop affecting the final quality of the painted glass. While it is true that dust will spoil the quality of the paint surface, the small-scale user without sophisticated drying equipment or dedicated drying areas can take comfort from the fact that in most projects, the paint surface will not be seen directly. In the case of wall cladding, tabletops, counters, etc., the viewer will be seeing the front of the glass, and the paint will be on the back.

Bearing this in mind, as long as care is taken to ensure that the area for paint application is as clean and dust-free as possible, if the drying has to be done in a less dust-free area, a small contamination of dust on the paint surface may not seriously affect the final result. It is of course best to ensure a dust-free production process from start to finish where ever possible.

Air vs. Tin Side of Float Glass:

Float glass has two sides: an air side and a tin side. To check for the tin side, run a UV light over the glass. A cloudy appearance indicates the tin side.

Painting Recommendation: Apply Vitrocoat to the air side of the glass for optimal results. When painting multiple panels of glass painting the air side is one way to achieve consistency in the color of each panel.

Glass Selection: Vitrocoat can be used with a wide variety of glass.

• Laminated glass
• Tempered glass
• Annealed glass
• Curved glass
• Textured glass
• Tinted glass
• Fused glass and more!

Glass with Metallic Coatings: Paint the non-coated side for best results. Conduct adhesion tests before painting the coated side.

Color Selection:  Since most glass has its own natural tint depending on type of glass, we recommend following these steps to make achieve the best paint match.

1. Take a sample of the intended glass.
2. Place it over the paint color chart used for selection.
3. This accounts for any inherent color tint in the glass, ensuring client satisfaction with the final result.
4. Color Shift with Clear Float Glass: Slight green tint in clear float glass can alter the perceived color of the paint.

Recommendation for White Glass: Use low-iron, ultra-clear glass for true white paint color. Read our aticle on color matching paint for Whiteboards

Installation.

Completed panels may be safely installed using Neutral-Cure silicone. We recommend Dow Corning silicones, which have been tested for adhesion and compatibility with Vitrocoat by Dow Corning themselves. Read our article on installing back painted glass

Demonstration of Vitrocoat’s Durability:

See test results : Stringent ASTM tests, TUV and Enova confirm Vitrocoat’s enhanced durability and adhesion.

• Optional Hands-on Demonstration:
  1. Mix PU paint and hardener (without Vitrocoat) according to the manufacturer’s instructions.
  2. Spray this paint onto a clean piece of glass (control sample).
  3. Repeat using the same paint with Vitrocoat (following instructions). Ensure both glass pieces are clean and receive the same amount of paint.
  4. After drying, scratch the painted surfaces to compare scratch resistance and showcase the clear difference Vitrocoat makes