KirbyWan
Aerospace
- Apr 18, 2008
- 586
Howdy all,
I work for an FAA repair station. We do, among other things, bonded metal panel repairs. These are aluminum panels that have new skins PAA anodized using a process based on BAC5555. Where we can't PAA anodize, we use a non-tank etching process such as Boegel. Details are bond primed and assembled in a clean room using tooling to maintain part contour and cured in an autoclave. This is just to give an understanding of what kind of processing we do.
Currently we run a process validation coupon, usually a lap shear, sometimes with a climbing drum peel, flatwise tensile or floating roller peel, with every autoclave run, and I think this is excessive and would like to create a specification to detail when process validation coupons are required. I'd like to get a sense from the community of what standard industry practice is for process validation. Are we over testing? Is this right where we should be? I know for manufacturing usually one test is done per batch of adhesive film used, which is acceptable because of the higher production rate and high quality of tooling used.
My plan was to have the process spec say something like: "run a process validation coupon with every autoclave run unless Engineering has determined for a repair process that alternate testing requirements are acceptable." We would have a section for specific part numbers of panels that have had a consistent history of acceptable results and use less frequent testing in those instances. Does that sound reasonable?
Thanks for your comments.
-Kirby
Kirby Wilkerson
Remember, first define the problem, then solve it.
I work for an FAA repair station. We do, among other things, bonded metal panel repairs. These are aluminum panels that have new skins PAA anodized using a process based on BAC5555. Where we can't PAA anodize, we use a non-tank etching process such as Boegel. Details are bond primed and assembled in a clean room using tooling to maintain part contour and cured in an autoclave. This is just to give an understanding of what kind of processing we do.
Currently we run a process validation coupon, usually a lap shear, sometimes with a climbing drum peel, flatwise tensile or floating roller peel, with every autoclave run, and I think this is excessive and would like to create a specification to detail when process validation coupons are required. I'd like to get a sense from the community of what standard industry practice is for process validation. Are we over testing? Is this right where we should be? I know for manufacturing usually one test is done per batch of adhesive film used, which is acceptable because of the higher production rate and high quality of tooling used.
My plan was to have the process spec say something like: "run a process validation coupon with every autoclave run unless Engineering has determined for a repair process that alternate testing requirements are acceptable." We would have a section for specific part numbers of panels that have had a consistent history of acceptable results and use less frequent testing in those instances. Does that sound reasonable?
Thanks for your comments.
-Kirby
Kirby Wilkerson
Remember, first define the problem, then solve it.