You correctly describe the contents of the concentrated BASE SOLUTION that I mix up and then use when making refilling my ultrasonic tank. The Base Solution is useful because it stores indefinitely at room temperature. My formula for the Base Solution, as you quoted from the article in Positive Feedback, is:
40.00 ml Tergitol
30.00 ml Hepastat 256
48.00 ml 91% Isopropyl to top out the bottle at 118 ml
Creating a total of 118.00 ml Base Solution
I make up containers of 118 ml of Base Solution because that is the size of the tinted glass chemical storage jars I have. I’ll make up 4 or 5 of these Base Solution jars at a time, seal them, and put them on the shelf until needed. If you have larger storage containers, just adjust the amounts proportionately.
When mixing up a 10L tank of cleaning solution (about 2 gallons), I add 29.5 ml of the Base Solution to 405 ml of 91% isopropyl alcohol and put that into my tank. Then I top up tank with filtered/deionized water.
If I were filling a 6L ultrasonic tank, I would use 60% of this. In milliliters, I would add 17.7 ml of the Base Solution to 243 ml of 91% isopropyl alcohol and put that into my 6L tank. Then I’d top up the tank with filtered/deionized water.
You asked about a source for the Hepastat 256. I suggest checking with Quill.com. They sell 1/2 gallon containers for about $25. Here’s the link: https://www.quill.com/brighton-professional-hepastat-256-restroom-cleaner-handy-mix-dilutable-64-oz/...
You finally ask about drying the record after cleaning. In my tests, VACUUM DRYING was critical to achieving the results I was looking to accomplish. Allowing the record to air dry simply allows whatever residue may still remain to dry into the grooves of your record. Results with my previous four-step manual cleaning using a VPI wet/vac machine were as good if not superior to the ultrasonic cleaning when the US cleaned record was allowed to simply air dry. As always, we may hear different things, but this is what we decided here.
Hope this helps!