Possible new intel on this issue!
I've been testing a bunch of ideas for ballasting to make it go faster [and jump higher], and started experiencing the talc residue problem where I had not seen it before. First, there is a solution - wet (just water) toothbrush. Once the ballast is fully dry and set, lightly scrubbing the residue dissipates it to where it isn't noticeable. It might take a two or three passes, but it will eventually vanish.
The other thing I've discovered is there may be an issue with "old" diluted medium. The bottle of 4:1 Liquitex I was using was mixed several months ago. My theory is "simply" adding water upsets the as-manufactured balance. With age the talc might be precipitating out of suspension, and mere shaking isn't going to put it back. I didn't have any issues when it was freshly diluted.
Something else to ponder is I am now using Vallejo medium. It is working exactly as I wish it to with no residue. But, again, that is a fresh mixture. Only time will tell whether the residue issue is an aged-solution problem or if Vallejo medium >> Liquitex medium in this "off book" use.
