DESCRIPTION

Type DK^TM spatter coats are factory blends of Portland cement, vermiculite and other materials. It is for use as a pre-coat to improve fire protection performance on some substrates, including metal deck systems incorporating flat plate sections. Type DK^TM spatter coats improve the reliability of some cementitious fireproofing applied to thin metal sections by helping the fireproofing to resist fall-off.

USES

Many Underwriters Laboratories Inc. Fire Resistive Designs require that one of the

Type DK^TM spatter coats be applied to substrates before the application of fireproofing. Use of a spatter coat is optional on other steel surfaces. The spatter coat is included as a part of the required fireproofing thickness. Type DK^TM is specified in most designs requiring a spatter coat when Type 5^TM products are used. However, Type DK2^TM is required with Type 5^TM products in UL Design P741.

Type DK3^TM is specified in designs requiring a spatter coat in combination with Type 7GP^TM fireproofing.

To avoid using more than one Type DK^TM on a given job, Type DK^TM may be replaced with either DK2^TM or DK3^TM and Type DK2^TM may be replaced with Type DK3^TM.

MATERIALS

Spatter coat is to be Type DK^TM as manufactured by Southwest Fireproofing Products Company or its licensed manufacturers.

Mixing water is to be clean, fresh and suitable for domestic consumption. Water is to be free of minerals or organic substances that affect the set time or strength of Type DK^TM.

Retarder is to be Red Top Plaster Retarder as manufactured by United States Gypsum, or equal.

DELIVERY AND STORAGE

A. All material is to be delivered in original unopened packages bearing the name of the manufacturer, the brand and proper Underwriters’ Laboratories, Inc. label for fire resistance classification.

B. The material shall be kept dry until ready for use. Packages of material shall be kept off the ground, under cover and away from sweating walls and other damp surfaces. All bags which have become wet before use shall be discarded. Stock of material is to be rotated and used before its expiration date.

APPLICATION

Application procedures are to be as described herein. Type DK^TM shall be applied as a discontinuous spatter coat covering only about 50 to 70 percent of the substrate area. The entire substrate surface is not to be covered. At least 30 percent of the deck must remain visible after application. Adjust the spray pattern to achieve a rough textured coating with these characteristics. Coverage is to be approximately 800 sq.ft. per bag.

SURFACE PREPARATION

All surfaces to receive Type DK^TM spatter coat shall be free of contaminants including loose mill scale, dirt or other foreign materials which may impair proper adhesion of the spatter coat to the substrate.

JOB SET-UP, EQUIPMENT AND SPRAY INSTRUCTIONS

GENERAL

Use standard cementitious fireproofing pumping equipment for efficient application. Alternately, Type DK^TM spatter coat may be pumped with smaller machinery located on the application floor for convenience. Small progressive cavity pumps, such as the Essick FM 9 rotor/stator pump or the Quick-Spray peristalsis pump are satisfactory.

Efficiency is improved by limiting the number of Type DK^TM spatter coat applications. This avoids unnecessary interruptions of fireproofing application. One application of enough spatter coat for the full day’s production can be followed with Type 5 application without further interruption. The first batch of Type 5 immediately following the spatter coat should be retarded.

JOB SET-UP

If a large plaster pump, as used for Type 5 application, is used to pump spatter coat through the main system to the spray nozzle, the pump should be operated at a low speed with a 3/8" diameter orifice used for application. If a smaller pump is used on the spray floor, the speed should be adjusted accordingly. A pole gun of sufficient length to apply the spatter coat without scaffolding is recommended.

MIXING PROCEDURES

Type DK^TM spatter coat is formulated to be mixed with water in a mechanical plaster mixer to form a cohesive, uniform slurry of 45 – 55 pcf. About 13 gallons of water per bag of Type DK^TM should be added to the mixer first, followed by addition of the Type DK^TM dry mix. A mixing speed of 35 – 45 rpm provides proper mixing in about 2-3 minutes. (The mix will appear wetter than Type 5^TM materials).

PUMPING

Large plaster pumps and hoses should be primed with a small amount of water. The pump should be started in low gear with enough water in the pump hopper to flush the system. When the hopper is empty of water the mixed Type DK^TM should be dumped into the pump hopper and spatter coat spray application begun.

The mixer must be dumped and emptied completely of the last spatter coat batch before switching over to Type 5^TM. Either the hose should be flushed out with water or the first batch of Type 5^TM following the Type DK^TM should be retarded with 5 oz. of plaster retarder. This procedure is to avoid fast setting of the first batch of Type 5^TM. Avoid mixing of the last batch of Type DK^TM with the first batch of Type 5^TM by pumping the hopper empty before dumping Type 5^TM into the hopper.

Whenever changing products the pump hopper should be allowed to completely empty and the sides scraped clean. Where mixing blades do not clean the mixer, a small amount of water should be added to the mixer and dumped into the full pump hopper to help empty the mixer completely.

CAUTIONS

Type DK^TM contains Portland cement and may cause staining of other construction material and other finishes. Exercise care to minimize over-spray and use proper protection methods.

Wet slurry can cause floors to become slippery. Take precautions to minimize foot traffic in work area and post "Slippery Floor" signs.

End of section 2/2005

Southwest Fireproofing Products Company, Albuquerque, NM 87107 Phone: (505) 345-1633

©2004 Southwest Fireproofing Products Co.

Southwest Fireproofing, Type 5GP, Type 5EF, Type 5MD, Type 7GP, Type 7HD, Type 1XR, Type DK, Type HC and Type 7TB

are trademarks of Southwest Fireproofing Products Co.