Donrex have two types of investment casting processes: silica sol process and the water glass process.

The silica sol process is used to cast complex high quality parts with requirements of a very good surface finish and close dimensional tolerances. 

The water glass process is typical of the process in the early stages of investment castings.  It generally is capable of much larger castings than the silica sol process, but does not have as good of surface finish or tolerances. The water glass process provides parts that have better surface finish and dimensional tolerances than sand castings.

Silica sol investment castings can range from a weight of just a few ounces to approximately 80 pounds. If you are concerned with precision in very small parts, we are especially proficient at very fine detail work including teeth and serrations. Water glass castings may range in weight from several ounces to approximately 200 pounds. 

First article layouts and spectrometer material certifications are provided with all first article samples.

A variety of secondary operations can be performed on both types of investment castings. They include heat treatment, machining, plating, painting, polishing and buffing, assembly services and even custom packaging.