Simple Solutions That Work! Issue 7

• The sand should be a consistent color from beginning to end – Dark areas indicate excess resin – Loose, dry sand indicates lack of resin • Most current mixers have On and Off Delay Timers for both Sand and Resin – Adjust timers as necessary in order to get a consistent color/wetness of sand • Some older mixers will utilize flow control valves on the slidegate cylinder hoses to control the speed of the slidegate to adjust sand start stop speeds. Open or close those valves as necessary to dial in the slidegate speed to achieve a consistent liquid/sand mix at the beginning and end of the cycle • Also look at the consistency of the mixed sand. Some resin systems are more difficult to mix and will leave Resin Balls in the sand. With the board test, the presence of resin balls can be evaluated and used to help eliminate them through blade changes, etc. Compaction Force–Drop & Stop Many customers underestimate the importance of compaction during the molding process. Compaction will deliver a more dense, consistent, stronger mold. However, compaction should be quick and limited. Allowing your compaction table to run after optimal mold density has been achieved will often do more harm than good. Ideally, compaction time should stay consistent and brief. Force output should be varied based on the mold size. In order to determine an optimal setting for a specific mold on your systems, we recommend: • Decide on a compaction time such as 5 seconds • Fill the pattern with mixed sand • Strike off the top surface • Run a compaction cycle • Pay close attention to how long it takes for the sand to drop and then stop settling • Adjust force output of the vibrators and retest until the stop occurs just before your decided compaction time expires • Note the desired force output to the specific pattern/mold and utilize that output setting for any future production of that specific mold • A video example of this process can be seen here as a reference: www.palmermfg.com/videos/sand-compaction.htm CLICK HERE TO WATCH THE SAND COMPACTION VIDEO » All of the above items are quite basic, but are fundamentally important to delivering consistent, quality molds, which will eventually help lead to consistent, quality castings. Contact: RICH McNEELY [email protected] 52