Analysis for the not dry or slow drying of the SPU material when installation
When installation, the materials don't dry or get dry very slowly, in our experience there're only two reasons: the water and the thinner.
When producing, the material is vacuum dewatered, and do the second reaction purification and other processes, so that the material achieves 0 water content and insuring the material quality before applying. As long as the foundation of the construction site is dry( water content is less than 8%) and the air humidity is less than 60%(not wet and non-sticky), it can add 0.4% water of the weight of the middle coat material, the mixture is fully stirred. Then the reaction can be completed. Of course, the technician should adjust the water according to the on site foundation and the air humidity. If the water consumption is insufficient, the site will not dry or dry very slowly. If the water consumption is too large, the site will bubble. There is a dry place and there is a not dry place in a same site, it must be caused by uneven water or uneven mixing. If there is uneven mixing, there will be bubble or foaming in some spots. The curing time of the normal design is 8 to 12 hours. If the site is not dry after the normal curing time, th e site will have question such as wet mud, sticky feet, sticky ash, watering and discoloration.
During installation, it's necessary to add thinner to control the leveling. The tar-containing thinner(methanol, ethanol) containing alcohol will directly destroy the molecular structure of the material, resulting in insufficient reaction or not drying or slow drying. And the performance would not meet design requirements and affect service life.