Avoid Cross Contamination
It seems that when it comes to mixing refractory materials, the lion’s share of the attention goes to water content, mix time, and temperature. This, in most cases, is for good reason, but there are other considerations refractory installers should make prior to and during installations. One such consideration is the potential for cross contamination of products as well as the potential sources of this problem.
Contrary to popular belief, refractory monolithic products are more than simply “dirt in a bag.” Refractories have different base materials, additive packages, bond structures, and even mixing agents. People often hear phrases and characteristics such as “phos bonded”, “cement free”, “high alumina”, “colloidal silica”, “low iron”, etc. when they are determining which materials to use for their specific application. When working on a project that involves various material types, or just as important, when using equipment that has been used with various material types, it is critical to avoid cross contamination.
Cross contamination of refractory products can result in many costly problems. The set time of the material can be impacted. Increased set times can alter the as installed properties of the material or cause serious damage to equipment. Decreased set times, can also alter the as installed properties of the material, and may even lead to having to remove and re-install the materials causing substantial delays and exorbitant costs.
The best way to avoid cross contamination is to closely monitor material storage, and more importantly, thoroughly clean mixing equipment after each use. Refractory curing is a chemical reaction so even a small amount of cross contamination can create significant issues. Simply getting the equipment “pretty clean” or “clean enough” can cause problems on future installations. It can be difficult to make thoroughly cleaning mixing equipment a priority as it often occurs after a long hard work-shift. It takes discipline to make the extra effort and take the extra time to ensure that this task is adequately accomplished. Whether using a drill motor and a bucket or a large bulk mixer and a pump cleaning equipment is critical to successfully installing refractory monolithic products.
For more information about cross contamination or to ensure that these common mishaps do not occur on your next capital or maintenance project, reach out to Schad today!