 | ||||
| April 2010 | Courtesy of BEGO USA |
||||
Smooth Connections for Porosity Free Castings Porosity or pits, within the margin area, can be caused by investment material that is carried by the alloy to the furthest location in the restoration. To help prevent investment break-down, make sure all wax connections are smooth and have rounded corners so the alloy can flow without any restrictions (photo A). For partial frameworks, the connection of the feeder sprue should be angled in the same direction as the flow of alloy - not at a right angle (photo B). If the sprue is perpendicular to the refractory model, the alloy could breakdown the investment as it enters the pattern, causing porosity to be found in the clasp tip or mid-line area. Also check to make sure the area underneath the sprue former, where the two or three feeder sprues originate, are rounded off as well. BEGO hopes these tips will help eliminate costly remakes and improve the quality of your castings. |
 |
|||
Photo A |
Photo B |
|||
 For more information, call your local dealer or BEGO USA, 1.800.342.2346 | www.begousa.com | |
 |