Stabilization according to Webster's is a substance added to another substance to prevent or retard an unwanted physical state; to become stable, or firm.
As a knifemaker stabilization of handle materials helps to maintain the natural color of the material being used as well as making it stronger. Whether using wood or other natural materials that swell, and shrink with normal pressure changes thus resulting in checks and/or cracks of the material being used. Also, with natural materials age as well as ultra-violet light such as sunlight will age, or change the color of many natural materials. Stabilization of handle materials will add weight to the handle material as well as making it harder, and less prone to any color change.
The Process of Stabilization:
1) Material is placed into an airtight container.
2) The stabilization material is added, (Note: You may need to weight down the material, I use small pieces of plain steel for this).
3) Create a vacuum of approximately a negative two (2) atmospheres or a negative thirty pounds per square inch (-30 psi), (Note: Initially when the vacuum is created the air will be pulled out of the handle material, and collect as foam at the top of the container).
4) Leave the material in the vacuum for approximately 12 hours. To do this clamp off the hose once the negative pressure has been achieved, turn off the vacuum pump.
5) After the allotted time release the vacuum pressure via the hose, and repeat item 4) for another 12 to 16 hours. After the allotted time remove the material from the container. Place the material on waxed paper, or freezer wrap to dry, (Note: Material should dry for a minimum of three days prior to use).
Making the Vacuum Chamber
I've heard of all different types of containers used as vacuum chambers, from pressure cookers to glass jars. I use glass canning jars with glass lids, and rubber seals. I use a diamond bore cutting bit to cut through the lid, (see photo). When cutting the hole into the lid use dish washing soap as a lubricant or cutting fluid. With the lid braced on a wood block and a pad (a rubber mat pad works best to keep the lid from vibrating and possibly cracking). Drill the hole at the slowest possible speed. Once the hole is cut into the lid, insert the nipple assembly into the lid. Use the bottom of a plastic cup with a hole in it to build up epoxy around the nipple and the top of the lid. Once the epoxy is set on the top of the lid the same needs to be done on the inner lip on the inside of the lid.
The Safety Collection Jar
A second smaller jar needs to be made with two (2) nipple assemblies. This is a safety collection jar used to collect any excess stabilization fluid keeping it away from the compressor.