The application of impregnants has lifted productivity to a new level for the casting industry. Nowadays, numerous enterprises in the foundry sector have regarded impregnation as an indispensable process, which is widely applied in automotive, motorcycle, railway, air‑conditioning refrigeration, aerospace and other industries. Certain problems are inevitable during impregnant usage. Several common issues are analyzed as follows:

Problem 1:

Storage of this product under high‑temperature conditions may trigger polymerization and curing failure.

Solutions: Impregnant stored in the glue tank shall be equipped with a chiller to keep temperature within 5‑20℃. If the system is shut down in winter, check whether the chiller works properly before restarting. Unopened barrel‑packed impregnant must be stored below 28℃.

Problem 2:

Air acts as a stabilizer for this product. Upon long‑term shutdown, the impregnant at the bottom of the storage tank cannot be exposed to air for a long time, which impairs liquid stability.

Solutions: During shutdown period, circulate the impregnant three times daily between the impregnation tank and storage tank to enable the bottom‑layer impregnant to make contact with air. This operation is unnecessary for daily production. Better performance can be achieved by installing an air pipe at the tank bottom. Keep the valve slightly open to continuously feed a small volume of clean air during shutdown or off‑hours. (Air must pass through an oil‑water separator to prevent excessive water from entering the liquid.)

Problem 3:

When impregnating copper and iron workpieces, copper and iron debris will be mixed into the impregnant. Active copper and iron ions serve as curing catalysts for the impregnant. Under adverse conditions of high ambient temperature and insufficient air access for bottom‑layer liquid, the existence of copper and iron ions will accelerate premature curing failure.

Solutions: This product is designed for non‑reactive metals and non‑metals such as aluminum alloy, magnesium alloy and stainless steel. The manufacturer provides three‑quality guarantees when used for above‑mentioned materials with correct operations. No three‑quality guarantee is offered for copper or iron workpieces. If users apply it for copper or iron parts at their own risk, besides strict compliance with operating specifications, a bag‑type filter (available from the manufacturer) with 400‑mesh filter bag must be installed between impregnation tank and storage tank. Filter the liquid once before daily off‑work to remove copper and iron debris brought in by workpieces. In addition, add just enough liquid to submerge the basket and replenish as needed.

The above are common problems occurring in impregnant application.