Originally Posted by base2

Carbon repairs should not be done only to the outside. Any internal damage will continue to propagate until it is far beyond the repair area until eventual failure. A proper repair involves mapping out the internal damage by some means, (X-rays, sound, etc ..) removing all of it, how ever deep down and wide it goes by means of abrasion. Then examining the layup and orientation of each layer and making a pattern with successive layers of mylar and sketches of each. Then Re-laying down each piece in the proper orientation in order with an all encompassing additional top layer. From there a vacuum bag and heat. When cured, sand and blend the top layer to the unaffected areas, primer and paint as normal.

The difficult part of a bike tube is backing up the back side of the repair should the damage extend that far down. Surely there must be a way with an air bladder or expanded and profiled foam or whatever, but that's what the professionals are paid for.

So yes. The inside must necessarily be examined. It's just accomplished from the outside.