Preparing newly machined Inconel 718

When the Inconel is fresh from the machine shop, it will be contaminated with machining oil and dirt. Usually this involves wiping off the majority of the contamination with a Kimwipe, but the main cleaning is performed by sonication in acetone followed by sonication in IPA.

For large pieces like the chamber and adapters, there is a large sonicator in the Structural Materials Processing Lab (MPL). It is not big enough for the chamber, so a secondary container (like a bucket) will be necessary. This is going to contaminate a large volume of solvent, so consider saving the solvent and reusing it.

For threads that are going to hold high pressure (this includes the threads on the window housings, the window threads on the chamber itself, and the outlet and inlet gas ports), they need to be "lapped" using a lapping compound and the corresponding mating component.

The lapping compound is essentially a polishing compound, and it should be rubbed onto the male and female threads. Then the male piece should be inserted and removed, with a small pressure applied, repeating this 5 times. Then reverse the direction of the pressure applied and repeat another 5 times. Thoroughly clean the threads of any residual lapping compound, then move on to the next finest lapping compound and repeat until you have achieved the highest quality polish.