Air conditioning season is not off to a good start this year. The high pressure line that is routed under the battery developed a pinhole leak. The tube showed signs of corrosion, probably caused by battery acid. I attempted a repair by cutting out a few inches of metal tubing and bridging across the gap with some of the high-pressure rubber hose that's used for fuel injection. This was a good snug fit secured by standard hose clamps. The fix worked for a couple of weeks until one end of the hose blew off.
I reconnected the hose using a touch of Aviation Form-A-Gasket, but I don't have any confidence in this repair. I expect another blow-out.
There is another '03 Forester in the junk yard at the moment, but its high pressure line has a similar, though less-severe, corrosion problem. The tubing is also available new from the dealer, but it looks to be a major effort to replace while the engine is in the car.
Question: How would a pro fix this problem?