This is the stuff I got: https://www.eastwood.com/eastwood-rust-encapsulator-aerosol-red-15-oz.html
I think it is different than the stuff you are talking about.
https://www.eastwood.com/eastwood-black-rust-encapsulator-paint-over-rust.html
I am pretty sure I have seen POR-15 in an auto parts store, but the best deal I have come across is Walmart.com:
https://www.walmart.com/ip/POR-15-R...ack-4-00-oz-can-Case-of-6-P-N-45006/171019325
This deal let you get six small cans which I think is a lot better than one large can. Once you open this stuff up it wants to harden. It is pretty easy to have the lid get stuck and have a total loss of what is left in it. The smaller cans are a lot more manageable letting you use a small amount at a time. Buying six makes sense if you plan to use the product on multiple restores over time.
I don't know about the other Eastwood products you are discussing, but POR-15 makes an awesome improvement. Not only does it eat up the rust and prevent more but it also notably strengthens rust damage metal. Don't get me wrong. If the metal is gone it is gone and POR-15 can't bring it back. But it will definitely reinforce metal that has been weakened by rust. It is sticky, messy stuff to work with!
The Eastwood product works exactly the same. I have seen some folks say it's better some not as good. Go figure. They both work well I like the Eastwood product only because it can be purchased in spray and brush on. POR15 IIRC is only available as brush on and you have to buy a spray apparatus to use it that way. Not economical for a small time user. For a body shop sure.
Larry, this is the stuff I have. https://www.eastwood.com/eastwood-rust-encapsulator-aerosol-red-15-oz.html
As far as I can tell, it is the same as the black stuff. As you can imagine, if it is dispensed through a spray can, it isn't real thick like it sounds like POR15 is. It is thin like a regular spray paint or primer. Is that how the black spray is as well?