Sunday, October 18, 2009
Opening up the barn where we store the boats this past Saturday, we were greeted with this frosty sight. It's getting to that time of year where we have to put the canoes away on the Sunday morning after class. The reason is the adhesives we're using. Wood glue (depending on your manufacturer's recommendations) needs to be at least 50 degrees Fahrenheit to cure properly. Epoxy also needs to be warm enough to properly as well. Again, the type of epoxy and the hardener speed will allow for different curing speeds and minimum temperatures.
If you don't let the glue or epoxy cure in warm enough temperatures, problems occur. The wood glue, if it freezes, turns bright white and the glue joints are weak. Glue in the bottle needs to be kept warm as well - while some glues will tolerate freezing and thawing, some will not and will "chalk up". Epoxy generally either will not cure or the cure will slow down. Epoxy curing is both temperature and mass sensitive - the more of both, the faster the cure.
Simply stated, we leave the boats in a "room temperature" environment overnight to make sure that the glues and epoxy have cured properly. After that, the boat can get as frosty as the one in the picture above.