Hi, TW!A new Lowes that recently opened up in my neck of the woods appears to have the Black Jack for about $10 a gallon (It has a 300 on the can, is this the right one?) In any case, the work was stopped so there is no recommended base for it...correct?
No, the 300 has 2 problems...it is fibered and it's oil-based. The Henry is water-based and non-fibered. And, you're correct...since Bill checked with GG (the company that makes BJ) and they said the water-based, non-fibered Blackjack was discontinued, work to find the best base for it was abandoned.
For folks interested in BW...I'm going to give a bit of advice. Do yourself a favor and just spend the 30 bucks ordering the HE558 online. If you're spending a lot of time looking locally, you're likely wasting your time.
Back when PFG was under development, I took an entire day driving to every hardware/paint store in the greater Cincinnati area looking for water-based, non-fibered aluminum roof coating. Took a day of vacation from work to do it! And, while I could occasionally find non-fibered, I could not find water-based and NF.
Seriously, between the time you'll spend, the frustration you'll feel, and the gas you'll waste...it's just not worth it. Spend the $3x to order it online and move on with your happy life.