Product Data Sheet


Application Instructions




Fireproofing Products


The Schundler Company




Surface Preparation and Substrates:



General Guidelines:  Before applying Classic 5 LD Fireproofing, surfaces and substrates must be free and clean of dirt, loose scale, oil, grease, condensation, excess rust, non-compatible primer, rolling compounds or any other contamination.  Where necessary, the cleaning of the steel surfaces shall be the responsibility of the general contractor.


Galvanized steel deck surfaces must be coated with Type DK material prior to application of Classic 5 LD Spray Applied Fireproofing, or metal lath should be attached. When Type DK material is used, it should be used in accordance with the manufacturer’s application instructions. The thickness of the Type DK material is included in the total final thickness of the Classic 5 LD material.  When DK material is not on steel decks, then metal lath shall be used as described in the UL design listing  (P743).


Non-Ferrous metals (aluminum, copper, etc) and wood and concrete surfaces may require priming.


Prior to the spraying of Classic 5 LD fireproofing, clips, hangers, support sleeves and other attachments required to penetrate the fireproofing shall be in place.



Application Equipment:



Listed below are some general equipment guidelines and recommendations for the application of Classic 5 LD Spray-On Fireproofing. Job site conditions may require modifications or additional equipment.


Mixers:  Use 8 to 16 cubic foot, 52-rpm heavy-duty mortar mixers with rubber tipped blades for scraping the sides of the mixer.





Model Number





FM9 and FM5E

Rotor Stator




Rotor Stator



PF 30

Dual Piston



PTV 700

Dual Piston




Rotor Stator




Rotor Stator

Super 2L6


HP 320 E

Dual Piston



Compressor:  Air supply should be a minimum of 9 cfm at 100 psi  (6.9 kPa) and higher when air hose distances are longer than 75’ (22 meters)


Material Line:  Minimum 1 inch (2.5 cm) I.D. hose with 300 psi minimum bursting pressure. For lengths over 50 feet (15 meters), use 1 ½ to 3 inch (3.8 to 7.6cm) I.D. hose. Do not reduce hose diameter by more than ¼ inch (7 mm) per 25 feet (7.5 meters) unless a tapered conical reducer equipped with a swivel fitting is used. A 10-foot  (3 meter) length if ¾ inch (19 mm) I.D. hose may be added at the gun for use as a whip.


Air Line:  Use ½ inch (1.3 cm) I.D. line with a minimum bursting pressure of 100 psi (6.9 kPa).


Spray Guns:   Use plasterer’s pole gun with 3/8-inch to 9/16-inch (0.95 to 1.27 cm) fluid tip.



Mixing and Thinning:



Mixing:  Follow directions on bag.


For each bag add 10½ gallons of water +/-    gallons. Mix for only 1 minutes at 52 RPM. Do not over mix and do not use more than 11¾ gallons of water per bag.


Density:  Wet density measurements are critical to obtaining correct dry densities. Mixer wet densities should be 45 +/- 10 lbs per cubic foot (0.80 +/- 0.08 grams per cubic centimeter).


Pot Life:  Classic 5 LD is designed to have a pot life of 2 hours but nevertheless it should be pumped as soon as possible. When ambient temperatures are higher, pot life may be less. Also, dirty equipment can accelerate the set times since set gypsum is an accelerator to unset gypsum.



Application Procedures and Conditions:



General:   If at all possible, mixed material should be sprayed within 45 minutes of mixing at 70 degrees F. (21 degrees C). Pump, mixer, and hoses should be cleaned with fresh water every 4 hours, and more often at higher temperatures.


Film build-up will depend on application methods, weather conditions, and equipment used. For applications requiring more than one coat or when applying overhead, a scratch coat of approximately ½ inch (13 cm) is recommended. Allow to set for approximately 4 to 6 hours at 70 degrees f (21 degrees C) before applying subsequent coats. For overhead installations, a longer set time may be required.


Application Conditions: 



Cleanup and Safety:


Cleanup:  Equipment should be cleaned with clean, potable water at least once every 4 hours and at the end of the day.



  1. Do not breathe dust. Use OSHA approved dust mask while mixing and spraying.
  2. For eye contact, flush with copious amounts of water in accordance with OSHA instructions. Goggles or safety glasses are recommended.
  3. Wash skin with clean water to prevent irritation.






Schundler Classic 5 LD is manufactured by:


The Schundler Company

10 Central Street

Nahant, MA 01908


732-287-4185 (fax)


Visit our web site to read more about

The Schundler Company and its products.


The Schundler Company has been providing perlite and vermiculite aggregates to the plastering and fireproofing industries since it started in 1951.


It has been manufacturing fireproofing products for over 10 years as a toll manufacturer and now is manufacturing Classic 5 LD, Classic 5 MD, and Classic 5 XY Spray On Fireproofing.



Rev: 2/4//04 6/11/04; 11/23/04