In 2011, my 9 month old all aluminum radiator started seeping where the vertical tubes met the bottom tank.
1 bars leak ginger root tab stopped the seeping, and after I'd drain and refill the radiator every other year, seeping would slowly restart, and one more tab would stop it.
I did begin to have some heater core issues in 2017, just low heat, but flushed and backflushed it into almost normal expected heat output after noticing the lack of heat in 17f weather. There could be blend door sealing issues regarding that too.
Last December, I had the PS pump off. The PS bracket bolts penetrate the water jacket, so I drained radiator again and drained to lowermost bolt.
While the radiator was drained i cleaned the bottom tube/tank mating area, where the seeping occurred.
I thinned regular JB weld with 91% rubbing alcohol, and sucked it into a syringe.
I injected it into the cleaned area where all the former seeping existed, before the bars leak tabs stopped it.
I refilled the system, and did not add a single bars leak tab, as had become habit when doing as drain and fill.
Drove cross country twice.
It's not lost a drop of coolant.
Heater working about 90% of expected.
but I keep the bars leak gingerroot tabs in the glove box, and will have no issues using them again if I start noticing coolant loss.
Stop leak tabs always have the chicken little's spending all your money replacing everything and predicting your imminent demise.
I believe the 91% IPA alcohol to be an imperfect JB weld thinner. I think xylene would be much better for this task.
But perhaps the 9% purified water in the 91% IPA, makes the cured JB weld just soft and flexible enough to make my 'patch' last two cross country journeys.