blakmax
Member
Hi Gary
Sorry about the lengthy PPRuNe thread. I really wish I did have the time to filter it. Essentially much of what I said is in DOT/FAA/AR – TN06/07, Apr 2007 BEST PRACTICE IN ADHESIVE BONDED STRUCTURES AND REPAIRS which is available through the FAA Tech Center Library. I was the primary author of that document. US residents should be able to access it on line, but we foreigners can not access .gov sites because of homeland security limitations.
The reasons I favoured the AC 130 system are that it comes pre-measured, it is commercially available, its packaging reduces the risk of contamination and it works with most epoxy systems on a number of metals and alloys. I don't have any specific data for 6061, but I do know it works on 2024, 7075 Titanium and some stainless steels. I urge people to grit blast rather than hand or machine abrasion.
I have a lot of experience with the Australian grit blast and silane coupling agent system which performs very well. The AC 130 system uses the same silane but has other additives which do make some difference. With the GBS system, we were able to reduce the repair in-service failure rate from 43% in 1992 to only three bond failures out of well over 4000 repairs since 1992.
By the way, lap shear tests and peel tests are not sufficiently discriminating to use for qualification of surface preparation processes. The best accelerated test is the wedge test ASTM D3762, BUT ignore the stated acceptance criteria. Use the ones in the reference above.
Regards
blakmax
The reasons I favoured the AC 130 system are that it comes pre-measured, it is commercially available, its packaging reduces the risk of contamination and it works with most epoxy systems on a number of metals and alloys. I don't have any specific data for 6061, but I do know it works on 2024, 7075 Titanium and some stainless steels. I urge people to grit blast rather than hand or machine abrasion.
I have a lot of experience with the Australian grit blast and silane coupling agent system which performs very well. The AC 130 system uses the same silane but has other additives which do make some difference. With the GBS system, we were able to reduce the repair in-service failure rate from 43% in 1992 to only three bond failures out of well over 4000 repairs since 1992.
By the way, lap shear tests and peel tests are not sufficiently discriminating to use for qualification of surface preparation processes. The best accelerated test is the wedge test ASTM D3762, BUT ignore the stated acceptance criteria. Use the ones in the reference above.
Regards
blakmax