How to Eliminate Sealant Contamination

Posted by Andy Marin on Tue, May 30, 2017 @ 08:51 AM

Customers often ask us how sealant is removed from machined features, like tapped holes. Customers assume that the holes are masked, but that is far from the truth. In this blog, we will discuss what in the vacuum impregnation process enables a casting to be properly sealed without excess cured sealant in unwanted areas (sealant contamination).

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FAQ: Impregnating Powdered Metal Parts

Posted by Andy Marin on Mon, May 15, 2017 @ 08:10 AM

Vacuum impregnation is commonly used as a preventative measure to keep castings pressure tight. But when use on powdered metal parts, vacuum impregnation is used as a value added process. In this blog, we will answer the common questions we receive about impregnating powdered metal parts and explain why it is a value added process.

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What is the Cost of Vacuum Impregnation?

Posted by Andy Marin on Mon, Apr 24, 2017 @ 03:19 PM
Manufacturers are constantly faced with the dilemma of either scrapping castings that leak, or sealing the castings through vacuum impregnation.  In this simplified example, we will review the costs of casting scrap compared to the cost of vacuum impregnation.
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Does Elevation Change Affect Vacuum Gauge Use?

Posted by Andy Marin on Mon, Apr 24, 2017 @ 03:10 PM

Paragraphs 4.4.2 and 4.4.3 of MIL-STD 276A requires a minimum vacuum of 29 inches of  mercury.  This requirement creates a dilemma for people performing MIL-STD 276A at elevations above sea level.  The reason: this scale is measuring vacuum relative to sea level and using a gauge with this scale at elevations other than sea level requires a correction. To understand this let's look at the operation of the gauge.

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Why Use Dry Vacuum Pressure Impregnation?

Posted by Andy Marin on Thu, Mar 09, 2017 @ 07:06 AM

There are three types of vacuum impregnation processes:

  1. Dry Vacuum Pressure (DVP)
  2. Dry Vacuum (DV)
  3. Wet Vacuum (WV)

Dry Vacuum Pressure (DVP) is the most commonly used process in Godfrey & Wing equipment.  To better understand the DVP process, this blog will discuss the process step by step, and its advantages. The following example illustrates engine blocks being impregnated in a traditional batch system.

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Porosity Classification System Helps Determine Solutions to Casting Leaks

Posted by Andy Marin on Wed, Mar 08, 2017 @ 02:41 PM

Water, as we all learned in basic chemistry, exhibits a unique phenomenon:  as it solidifies, it expands.  For other liquids in our physical world, solidification results in just the opposite:  shrinkage.

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Why Electronic Connectors Love Vacuum Impregnation

Posted by Andy Marin on Thu, Feb 09, 2017 @ 08:21 AM

Electronic connectors can be found everywhere, from automobiles to airplanes. Consequently, the effects of their failure range from the inconvenient to the tragic. The number of such failures can be reduced by better methods of sealing connectors against the conditions that lead to corrosion.

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Outsource vs. In-House: The Cost of Vacuum Impregnation (Infographic)

Posted by Andy Marin on Mon, Feb 06, 2017 @ 08:11 AM

The classic use of the Buy vs. Make analysis in the context of impregnation involves deciding whether it is better to outsource parts to a vacuum impregnation service center or bring in-house vacuum impregnation equipment.  The following infographic will discuss (as a percentage) the cost and internal rate of return (IRR) of outsourcing or installing vacuum impregnation equipment in-house. 
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Should Vacuum Impregnation Be Done Before or After Machining?

Posted by Andy Marin on Tue, Jan 24, 2017 @ 08:55 AM

Customers often ask us if vacuum impregnation should be done to castings before or after machining.  The following visual aids will answer this question.

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How Impregnation Makes Porous Castings Pressure Tight

Posted by Andy Marin on Mon, Jan 23, 2017 @ 03:58 PM

Ever since metal casting was first discovered, casting porosity, an area of sponge-like internal structure in an otherwise sound metal part, has been a problem. Porous castings may be caused by internal shrinkage, gas cavitation, oxide films, inclusions and combinations thereof. It can be found in virtually any type of metal casting or part, and is a particular problem in castings made from aluminum, zinc, bronze, iron, magnesium, and other alloys. Porosity is always present in powdered or sintered metal parts because of their structural nature.

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