Gaseous, I noted your comment:
A few years ago I was witness to an engineer (now no longer with us) treating a trailing edge main rotor blade delamination to a quick slap of some stuff with "Bell Helicopter" written on the tube. Needless to say by the next annual the 'bond' had failed.
How many aircraft repair manuals contain such procedures? Or worse yet, injection repairs where you drill holes in a sandwich panel and inject adhesive. Given that to get a bond the surface must be clean AND chemically active, you can never achieve thse conditions either by lifting an edge or by drilling holes. You only ever get two things out of injection repairs; 1. you fill the air gap so that if you tap it it sound as if it is bonded, and 2. you get a warm fuzzy feeling that you have done something. Structurally, you have achieved dead set zero. Such processes can never achieve even minimal bond strength. The surfaces are not chemically active and may be contaminated anyway, so there is absolutely no way chemical bonds can occur at the interface.
It is in fact better to just paint the skin at the disbond bright pink. This has many advantages:
1. Everyone knows that the component is disbonded.
2. It takes less time next inspection to find the disbond.
3. If you are careful in painting the area, you can actually monitor if the disbond grows.
4. You haven't penetrated the panel so moisture is kept out.
5. The additional paint provides corrosion protection.
Structurally, the results are exactly the same.
I have seen cases where structural failures occurred because of injection repairs and large components (up to 12 ft x 8 ft) departed the aircraft. I have seen rudders fail in flight because of injection repairs implemented during production.
It really is time that these repairs are prohibited. The organisation I worked for actually did prohibit them but with every new aircraft type acquired, there are the same old injection repairs in the manuals. Why do the regulators permit manufacturers to use these processes without any validation testing?
I defy anyone to show me test results (other than just NDT) which show any shred of evidence that injection repairs achieve anything!!!