Good question. I actually never heard of that type of repair. I have read rad manufacturers use epoxy, but it was not supposed to be a primary structural component, if I can believe what they shared. I spoke with a niche high performance epoxy manufacturer, and gave them my parameters for a solution on a radiator, <30psi pressure, <250F, and water/glycol long term exposure, constant pressure cycling. They were most concerned with the water/glycol exposure long term, seeping into the carbon fiber filament, which is not the case for a typical rad solution issue. Never got an answer that would not require testing, and that was beyond what I wanted to invest. Lets us know what you discover.

Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.