How to Spray Fiberglass
31 October 2023

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We have the solutions to help you achieve a precise ratio for an accurate application of fiberglass. Fiberglass application expands over many industries world-wide such as marine, pool/bath, recreational vehicles, and more.

Spraying Fiberglass – Benefits of Monitoring Material:

There are significant expenses that are required when buying production materials for spraying fiberglass. To ensure you’re not adding more costs than necessary, it’s important to have an efficient method to reduce waste. The solution is material monitoring.

The catalyst alarm helps you achieve an accurate mix ratio each time to eliminate waste, control cost, and create higher quality parts. It also comes with a list of benefits that make this process easier. The catalyst alarm:

  • Alerts your operator with visual and audible indicators
  • Ensures enough catalyst flow from your system to the gun and assists in creating the perfect mix ratio
  • Equipped with innovative sensor design measures to avoid false alarms, and it can work with all mix ratios.

The catalyst alarm also has built-in measures. If for any reason the catalyst fails, the alarm will specify the issue by letting you know if it is either: flow interruption, recirculation left open, or over-pressurized. This feature is great for operators as it facilitates diagnosing and correcting errors.

We also offers other material monitors to measure the amount of resin and / or fiberglass you have going on to your part. Conclusively, material monitoring makes it easier to train new and existing employees by setting up consistent application ratios. Our technology eliminates the guesswork so operators can confidently make each part to the right quality and specs you have laid out for them. The catalyst alarm and the CB-8000 material monitor allows you to make a part consistently every time on every new application.

Spraying Fiberglass- Benefits of Converting from Hand Layup:

Utilizing spray equipment will allow you to have greater efficiency, increased production times, and higher quality parts.

Spray-up, or chopping, is an open-molding process where resin and fiberglass are sprayed onto a reusable mold. The process is similar to the hand lay-up process. A release agent is first applied to the mold followed by a layer of gelcoat. Once the gelcoat hardens, a chop system can be used to apply the fiber resin mixture onto the surface of the mold. Once the material is sprayed on the mold, brushes or rollers may be used to smooth out the surface. Lastly, once the material has cured, the part is removed from the mold. The mold can now be used for the next part. There are several benefits to converting to the spray up method:

  • Material savings: Many companies find hand mixing materials in a bucket results in excess material being thrown away or inaccurate mix ratios. By utilizing a mix/meter system you will only use the amount of material you need to build your parts and save more.
  • Time savings: With a mix/meter solution, you can rely on the pumping system to deliver the exact ratios of materials needed. This cuts the time and intensive process of weighing out your materials and mixing them by hand, and then rushing to get it on your part. This removes the potential for human error of not mixing the right amounts or not getting everything done before your material starts to harden.
  • Combating labor shortages: By utilizing a mix/meter solution, you can maximize the labor you have. Instead of requiring people to measure out materials and keep track of what you need for your part, the machines technology will handle it for you. Re-purpose that labor onto a different part of the process that will let you get your products done quicker and more efficiently. We offer fully automated solutions to help combat labor shortages.

Converting from hand layup will be an extremely beneficial transition in spraying fiberglass.

Spraying Fiberglass- Setting Up Chopper Motor & Fan Pattern:

Let’s look at our VRC-1000 Chopper with a Talon Gun. Here’s a deep dive on the best practices for adjustments, settings, and maintenance:

  • Blade wheel adjustments: Use a tool to loosen the outer nut, then look on the back side where you will notice an egg-shaped part. Adjust the part where your blade wheel is coming into your tire and they should barely touch. As the day goes by you will want to maintain this adjustment so that you keep a good chop consistency on your part.
  • Adjusting the idler bearing and eccentric nut: The idler bearing is designed to keep your chop in the chopper. The barring should spin with the tension of the tier, and you must make sure to not over tighten it. The eccentric nut should also be adjusted to spin with the tension of the tier.
  • Tire Styles: We have three different options: white tire, black tire and blue tire. All tires are relatively similar, but note that the blue tire is a harder terameter.
  • The Motor: The volume of the motor can be adjusted by exhausting the muffler. Another part of the motor is called a manifold block. The block has two controllers; the air controller and speed controller. The air control should be turned all the way in and backed out one turn and locked down. Speed controller can be adjusted at any point, by pulling it in or out. Moving away from the manifold block there’s a shut-off valve. You can slide the valve backward and that will shut off your chopping motor while using your gun. Vice versa, you can pull the valve forward and the chopping motor will start. A key point to maintaining your chopper motor is oiling it two to three times a day. To dispense oil into your motor, take the speed controller out and put two drops in and place the speed controller back in.

Moving on to creating a proper fan pattern.

  • Your pump pressure, chopper shoot, and your spray tip determine an ultimate fan pattern. If you are experiencing chopper flyaway, first look at your chopper shoot and make sure your pump pressure is dialed in somewhere between 40 to 60 pounds. Always make sure that your shoot is aligned in the center with your tip.
  • Selecting the right process and equipment is vital to your production. Make sure you are using the right equipment to deliver exact material ratios that will produce a world class finish for your parts.
  • The line of gelcoat spray equipment was developed to correct many quality issues such as porosity, pre-release, post-curing, cracking alligatoring, and inconsistent thickness. With a catalyst-to-resin variance of less than one percent, the Patriot Gelcoat System delivers industry-leading precision and accuracy. Wear-resistant components and self-healing seals allow the system to run for longer periods of time.

The Talon Gun is a simple, lightweight gelcoat spray gun, which is available in both internal and external mix configurations. We also have accessories to ensure your materials are properly prepared for spraying.

  • It’s ideal to spray gelcoat from 18-degrees Celsius. We offer heaters to help you keep the proper temperature.
  • Agitation is also key to ensure proper consistency through your gelcoat. Of course, we also have agitators to help this process.

Spraying Fiberglass – Working with Fillers:

It’s important to note that filler works as an abrasive, causing extra wear on equipment. Balls, seats and cylinders are all components of the system that are often affected by filler.

Our Patriot System does not use a cylinder, making the system ideal for a production using high volumes of filler and avoids risk of damage.

Applicators and Spray Guns

We also have specialized guns equipped for filler-use such as our Talon gun with stainless steel head. When using filler, the filter inside of the filler housing will need to be removed. We recommend using an external filter or replace the filter with basket strainer or a wire filter to catch. Catching large particles will reduce the chance of immediate failure on a gun or pump.

*Magnum Venus Products. (2023, March 02). How to Spray Fiberglass. Retrieved from Magnum Venus Products: