Winter is right around the corner, and for many in areas where the temperatures will drop, construction must go on. One of the questions we are asked often is the feasibility of sealant application at temperatures below 40° F. Sealant can be applied successfully at temperatures below 40° F, given the issues associated with cold temperature applications are recognized in advance and proper precautions are exercised. We offer the four most important aspects to consider:
Areas the sealant will be applied to MUST BE clean, dry, and free of frost or any contaminating substance. Aside from frost, all other requisites mentioned would apply at temperatures at or below freezing as well.
Remember – Do not install sealant when the temperature is at or below the dew point. This is when the temperature at which the air is saturated with moisture vapor and liquid water (dew) or frost begins to form on the joint face.
Prior to and during use, the sealant should be maintained at a temperature which it is workable. Most sealants have a tendency to become stiffer and more difficult to work with as temperatures decrease. Two-part sealants must be mixed as reasonably warm temperatures to obtain uniform blending of the components (approximately 50° to 80° F).
Remember – Most sealants cure either by solvent evaporation, chemical reaction, or a combination of both. Cold temperatures retard both reactions. The main advantages of a slowed or retarded cure is longer “wet” time, which usually results in better ultimate adhesion to the substrate. The main disadvantages of a slow or retarded cure is the increased possibility of dirt pick-up due to prolonged tacky surfaces, and the increased rick of damage from physical contact during a soft or wet state.
***Under no circumstance should water emulsion (Latex) sealant be used at temperatures below freezing.
The joints to be sealant will be open to their widest dimensions as temperatures decrease. The sealant should be tooled accordingly to compensate for compression of the sealant when the temperature rises.
The most difficult aspect to weigh properly is the comfort of the mechanic. It items 1, 2, and 3 can be controlled properly, then the final criteria is the ability of the individual to operate satisfactorily at the cold temperature.