TM  10-8110-201-14&P Section IV. REPAIR OF DRUM 5-14.  Applying  Elastomer a.  Preparing  Surface (1) Lightly  scuff  the  surface  with  a  rotary  wire  brush or  suitable  roughing  tool. NOTE Be careful not to damage cord layer. b.  Degrease  Surface (1) Apply a small amount of denatured ethanol to degrease  the  surface. (2) Apply  a  coat  of  surface  conditioner  onto  the  prepared surface with a brush. Apply as thin as possible. Let dry for 2 hours. WARNING Skin  contact  should  be  avoided  by  the  use  of suitable protective equipment as harmful or irritant effect may result. c.  Combining  the  Reactive  Components (1) Mix the Elastomer with the following mixing ratio: 3 parts Base to 1 part Solidifier by volume. or 2.3 parts Base to 1 part Solidfier by weight. NOTE Complete mixing is the most important step in the  use  of  Elastomer (2) After using part of the Base component, the lid should be REPLACED IMMEDIATELY  to minimize the risk of skinning and consequential loss of material. (3) Apply the Elastomer directly onto the prepared surface with   a plastic applicator or  spatula. Press down firmly to remove entrapped air and to ensure maximum contact with the surface. NOTE From the commencement of mixing, MP Elastomer must be used within 20 minutes at 5°C  (41°F),  within  15 minutes   at 15°C (59°F), and within 10 minutes at 25°C (77°F). 5-14 Change   3 NOTE All mixing and application tools should  be cleaned immediately after use. (4) Allow three days  to cure properly. NOTE Once opened, the Elastomer will have a limited shelf life  of  six  months  under normal  conditions  of  storage in correctly sealed containers. A surface skin may result during this period, but after its removal, the  remaining material can be used  in the normal way. Containers must  be  stored in  a  dry environment  at  a  temperature of not more than 30°C (86°F). 5-15. Vulcanizing Part No. 13216E9170. a. Exterior Patch (Fuel Drums). (1) Clean  damaged  area  of  all  contaminants  and  foreign matter. Wash drum exterior with an approved detergent solution. (2) Refer to figure 5-10 and buff damaged area; buff the drum wall 5 inches (13cm) in each direction from tear. Remove  dust  and  rewash  with  detergent  solution. (3) Refer to figure 5-11 for typical patch pattern and prepare  patch  assembly  as  follows: (a) Cut first patch from 42153 stock. Cut patch large enough to extend 3 inches (7.62cm) in all directions beyond break. (b) Cut second patch from 42153 stock. Cut patch 1/2 inch (1.3cm) larger than first patch. (c) Cut a third patch from 42113 stock. Cut patch 1/2 inch (1.3 cm) larger than second patch. NOTE Under normal atmospheric conditions the cement will dry in 2 to 3 minutes. Excessive humidity will require longer drying time. Limit use of ap- plicator brush to 3918 cement. Do not use an applicator brush in more than one type of cement.