GFRG Gypsum

RimCraft has always been the leader in Gypsum processing equipment. Now that FRP manufactures the entire RimCraft line, expect even better.  We are currently building our own pumping system that promises to bring a new edge to our product. FRP builds both Spray for Facecoat and Chopper for backup as well as accelerated casting systems.

RimCraft set out in the mid 90's with the hope of improving technology in the processing of gypsum based products. Since then FRP has become the leader in providing tomorrow's gypsum processing technology TODAY!

RimCraft builds systems for spraying (GFRG) and dispensing catalyzed gypsum products. These products are used primarily for the Glass Fiber Reinforced Gypsum, GFRG, indoor architectural markets. Although we build standard systems, our ability to customize is where we really shine. The RimCraft Gypsum Spray Systems will also spray polymer modified gypsum (FMG), opening up the market for outdoor applications.

The RimCraft Gypsum Spray Systems were designed, engineered, and constructed to process gypsum materials in production environments, unlike competitor's systems on the market that were intended to process other materials such as cements. Take a closer look at the RimCraft Gypsum Spray Systems and you will easily notice why FRP has become the Leader in Gypsum Processing Technology.

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Gypsum Spray Systems


Frequently Asked Questions

Q: How is the RimCraft Gypsum Spray Equipment Designed, Engineered, and Constructed for gypsum processing?

A: The gypsum slurry and the accelerator are abrasive and corrosive materials that require compatible fluid passages made from Stainless Steel and certain plastics, RimCraft does not use Home Depot plumbing fittings that are made of steel.

Q: What is the accelerator and how does it work?

A: The accelerator typically is Aluminum Sulfate. It is used to give the operator control of the gypsum slurry set time. Gypsum slurry has a natural set time (Pot Life) when mixed with H2O. The average pot life is 30-45 minutes before the gypsum slurry begins to harden. This time is insufficient for mechanically processing the gypsum slurry because the entire system would need to be flushed to prevent the slurry from hardening in the spray system. There are gypsum retardants available that change the natural setting time of the gypsum slurry from 30 minutes to over 4 hours. This allows the operator to continue spraying for up to 4 hours before flushing the system. The gypsum slurry is pumped from the plastic slurry tank to the RimCraft Gypsum Spray Gun. When the slurry passes through the Stainless Steel Spray Nozzle the Atomizing Air is injected to burst the slurry into small droplets, creating a spray pattern. The Aluminum Sulfate Accelerator is injected into the gypsum slurry as it exits the spray nozzle. The slurry set time can be adjusted from 5 - 30 minutes, dramatically decreasing mold turn-over time

Q: Do I have to use the Gypsum Retardant?

A: It is HIGHLY RECOMMENDED, unless you are using a gypsum slurry that provides a pot life greater than 1.5 hours.

Q: Is the accelerator easy to adjust?

A: Yes! Simply turn one knob.

Q: Why use a peristaltic hose pump instead of a piston, diaphragm or rotor/stator pump?

A: FRP uses a our own designed peristaltic hose pump for it's ability to pump abrasive and corrosive materials. The slurry passages are engineered in such a way as to provide total residual-free cleanouts.  Piston or diaphragm pumps leave material in the corners that cannot be cleaned out. Rotor/Stator pumps can create too much friction for heavily aggregated slurries causing undue wear. This excessive friction can also cause premature curing of the slurry in the spray hose that can get expensive. The RimSpray pump is easy to disassemble to replace a hardened hose by dropping down the lower housing and the rotor while leaving the entire drivetrain intact.  RimCraft Gypsum Spray System peristaltic pumps are:

Sealless -  Dry-Running -  Self-Priming to 27'
Abrasion Resistant - Reversible Rotation
Metering Accuracy to ±1%  
Integral Conventional Gear Drives

Q: How does a peristaltic hose pump work?

A: Peristaltic pumps work using the process of peristalsis to pump products through a hose the same way that blood and oxygen are pumped around the body. The hose sits around a rotor which, when turning, compresses a segment of the hose almost flat. 
This compression is released as the rotor moves around the hose with the hose reinforcements causing it to spring back to its round shape, thus creating a partial vacuum refilling the hose. This compression creates a seal and, as the rotor turns, any product on the discharge side of the rotor is propelled forward and displaced from the pump. Combining this suction and discharge action results in a self-priming positive displacement pump.

Q: How is the RimCraft Gypsum Spray System different from other marketed gypsum equipment?

A: Most of the other equipment on the market that is being presented as gypsum processing equipment is lacking in technology. These systems are usually designed for other applications and are being modified to process a gypsum slurry. They typically work for the first few batches, then it becomes a high maintenance and troublesome piece of equipment. FRP researched the environments that the Gypsum Spray Systems had to operate in when we started to design our system. The system would be in water prone areas at all times, must require little to no maintenance and  flush quickly and easily with no disassembly of components. All components must be laid out for easy inspection and access. The system must be USER FRIENDLY! With all of this in mind, RimCraft set out to engineer a TRUE GYPSUM PROCESSING SYSTEM! RimCraft tested several pumps before chosen the current models, 1/2" and 1 1/4" peristaltic hose pumps. The entire system can be flushed with less than 8 gallons of water and in less than 10 minutes. The RimCraft Gypsum Spray Gun is modular in design. The spray nozzle is CNC Machined from Stainless Steel to provide long life. Competitor's are typically machined from a soft aluminum material. The pneumatic components are protected from the elements by a fiberglass control box enclosure. All fittings, clamps, fluid passageways are engineered and manufactured from Stainless Steel and certain plastics for corrosion resistance. The Accelerator Injection System is engineered to provide a accurate delivery of the hardener. The system can be plugged into any standard 15 AMP 120 Volt AC wall outlet. For worker safety, RimCraft Gypsum Systems are equipped with a Ground Fault Circuit Interrupter (GFCI) Plug.

FRP uses Direct Drive Gear Boxes and Motors to power the peristaltic pump. Others use a chain drive to power their pumps. The chain is prone to rust and slurry build-up, causing it to pop off. The chain is usually located in a position that makes it almost impossible to lubricate and is a maintenance nightmare when the chain pops off. All electrical components on the RimCraft Gypsum Spray System are sealed from water and can be washed down. All fasteners (including the nuts and bolts) are Stainless Steel to resist corrosion.

Q: Can the RimCraft Gypsum Spray System spray gypsum slurries that have aggregate mixed in them, such as sand?

A: Yes, all of RimCraft Gypsum Spray Systems can spray gypsum slurries with sand. However the GSHV2004 Gypsum Spray System is better suited for this application, due to the stronger pump hose and larger pump size. It is recommended to use a polymer modifier, such as the VF-812 sold by Smooth-On. The polymer keeps the sand in suspension. Consult your gypsum sale representative or Smooth-On for more information.

Q: Does RimCraft offer training and setup?

A: YES! When a customer purchases a RimCraft Gypsum Spray System we want them to get a fast return on their investment. FRP will come to your facility to setup the new system and train the operator for 2 days free of charge.  This offer is only good in the 48 US States. RimCraft will travel internationally but the customer must pay the airfare.

Q: Do you provide demos of the Gypsum Spray Equipment?

A: Yes, when a system is here at the FRP Manufacturing facility. We try our best to keep a system here at all times but they are usually purchased after a demo. We only provide demos here at the FRP Manufacturing Facility. Please Call to schedule a demo. We encourage you to ship a mold to us for your demo.

Q: Does RimCraft build custom Gypsum Processing Systems?

A: Yes. FRP has produced Gypsum Systems that were completely PLC controlled and built in mixer. Various chassis configurations and boom lengths. Please see our Custom Equipment Page to view pictures of these system. We will build to suit YOUR NEEDS!

Our Specialties

RimCraft has always been the leader in Gypsum processing equipment. Now that FRP manufactures the entire RimCraft line, expect even better.  We are currently building our own pumping system that promises to bring a new edge to our product. FRP builds both Spray for Facecoat and Chopper for backup as well as accelerated casting systems.

FRP is fast becoming a significant force in the GFRC equipment market. Already recognized as the leader in GFRG, we have applied these details to our Cement line. We have found that the details are what make a huge difference in promoting flow and EZ cleaning of these difficult-to-pump materials. Look for the RimSpray GFRC Mini for ease of maneuverability in small shops (ie: Concrete Countertops) and outdoor applications. The full size RimSpray Black Max unit is taking the GFRC Industry by storm!

FRP Equipment manufactures a variety of specialty Resin-Based equipment for the composites industry. From low-pressure diaphragm/ slave for RTM and Infusion to variable ratio Urethane and Epoxy units. We also excel in systems for Spray Granite Gel Coats along with sprayable Polyester Putties and Barrier Coats. We build the finest Putty Dispensers and Resin Casting systems on the market.