Hydrogen is a metalcaster’s friend — or foe. Depending on the type of castings they produce, hydrogen absorption by molten aluminum can be helpful or harmful. Using CMH MANUFACTURING CO.’s Hall Vac-U-Check, metalcasters are assured of a quick, simple, economical, and accurate method of monitoring the hydrogen level in the melt.
A vacuum solidified sample will exaggerate the size of a hole, making the analysis of gas in the sample easy to determine by visual methods or by using the specific gravity formula.
Using a Vac-U-Check unit is simple. Dip a quarter-pound molten aluminum sample from your furnace. Place the sample in the vacuum chamber for solidification. After the sample is cool, saw it in half for a visual inspection or weigh the sample in air and water to determine the true specific gravity.
Should you be producing premium-quality castings, a minimum amount of gas is required. If you are producing a commercial casting, a small amount of gas can be helpful to reducing shrinkage, thus simplifying gating, risering, chill usage, and improving yield.
The Vac-U-Check is one of several metalcasting accessories available from CMH Manufacturing. CMH produces the Hall line of tilt-pour permanent mold casting machines and foundry systems, with special emphasis on aluminum tilt pour gravity diecasting machines. It also supplies Stahl casting equipment, and other parts and new equipment. CMH also offers a full line of Autocast casting machines, casting catchers, rotary tables, peripheral workcell support equipment, robotics, and automation designed around the tilt-pour principle.