dtectr
Good suggestion to look up the material data sheet, when you can find them they can be a huge help.
If he is saying they have a Bakelite consistency, and if a twist of a screwdriver shatters pieces of the sidewall with only a little pressure, it seems to me they are of the brittle variety. If the connectors are old, they tend to be how he describes his. I have processed old connectors, whatever plastic they used back then becomes very brittle with age and then easily shatters when put in a ball mill, or hit with a hammer. I prefer the ball mill because hitting it with a hammer sends parts and pieces flying all over your workshop.
I try not to put anything into solution that doesn't need to be dissolved or consumed by the acids. The reason being is that it takes a lot more acid to strip pins in the connectors, to cover them, than it does to cover just the pins. Because you have all that excess fluid (you have to still keep up the ratios, you don't want to just add H20 until everything is covered with liquid) you have an excess of Nitric to evaporate off, or neutralize, or dilute whatever process you are using. If I am going to have a spill, I would rather a small quantity than a large.
It's true, I have done it. You can process several batches through the same solution until it becomes so saturated and pregnant with heavy metal, that it can no longer consume new connectors put into solution, but now you have to deal with all the solution captured in plastic, you have to rinse those off and save whatever fluid you can spray off them (some of it will contain Au), which adds more water to a process that already has a lot of waste liquid.
The spec sheet may only describe what material the connecters are made of, they may not come even close to describing what the plastic has turned into over maybe 30 years, that is, if they were made in the 80s. Or you might be able to get the specs, if they are still around, then read how time, exposure, oxidation, heat, cold, etc affects them. It would probably be a more scientific approach, and maybe even a better approach, but where is the fun? I took apart a radar system the other day, not because I needed to do it right then, to be honest I'm at a stopping point until I put my equipment together how I want it. But it did calm me, it was a nice stress relief, and I actually enjoyed trying to figure out how to take it apart. Which reminds me, I have some silver braided wire that I wanted to ask how to process best, I'll post pictures later.
On a side note, there are connectors that I pulled off of cables for hospital machines that when immersed in acid, turn very soft (I like to test on a small scale whatever material I am putting into acids). I was lucky I tested on a small scale because after a few short minutes the plastic turned really gooey. I once took a plastic cup I bought at a gas station, filled it with gas because my car had had run out, but before I could walk the gas back, the cup totally dissolved, the gas working as a solvent. It turned into sludge.
I probably don't have near the experience of most of the people posting in this thread, I am very new to all of this. My methods are surely not nearly as refined as people that have done this for years. The very reason I am reading this forum. If I have missed something, or my thinking is somehow flawed, I hope someone corrects me. I only offer my thoughts and observations and whatever little experience I have. I hope I have not offended anyone with my humor.
