Fire doors should be closed when sealed. If the door is not in operating condi- 

 tion the space should not be sealed, but the door should be repaired and closed 

 prior to the sealing operation. In sealing over the tracks of fire doors, paper or 

 other material should be placed over the track so that sealing materials can be 

 rapidly removed in order to place the door in operating condition. Binding agent 

 should never be applied directly on the track or roller of a movable fire door. 



A second point to be stressed in application is the thickness of the material. 

 It has been found that one pass of the spray gun will apply less than 0.005 inch 

 of solution. A pass in this instance shall be construed as the slow movement of 

 the gun from left to right and back to its starting position. Two passes of the 

 gun will, therefore, give a coating of between 0.005 and 0.0 10 of an inch — a 

 thickness entirely adequate in most instances for sealing purposes. It is evident 



N 10157 



Figure 11. — Application of plastic sealing to interior of a warehouse. 



that this application will considerably reduce over-all costs as compared with those 

 established by the Navy in the application of a heavier coating. 



Problems in Application 



Fumes Inflammable 



Wherever possible, plastic sealing should be applied from the outside of the 

 building in order to avoid any fire hazard. It is recognized, as stated under the 

 heading Safety, that the fumes of the solvents used are highly inflammable. 

 Where inside application is desirable, concentration of fumes should be avoided 

 by the use of exhaust fans. Where there are high ceilings or where adequate 



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