I don't think you killed the discussion... there's just not a ton of new information and everything that's publicly available we've already steamrolled in the discussion. I expect if/when new information is made public this thread will get hot again.
blakmax said:
What was the surface treatment for the titanium surfaces prior to bonding?
There are a couple of paths to activating titanium and/or resin surfaces to prepare for adhesive bonding (based on your stated experience, expect you're well aware of this already). At this point, I think the group consensus is that we suspect none was used, but we can't prove that conclusively.
blakmax said:
Were there appropriate tests to assess hydration resistance provided by those treatments?
Similar to the above... I think we all suspect the answer is no (I certainly do) but we can't prove it.
blakmax said:
Importantly, all fibres are treated with a "size" to prevent damage during manufacture.........
blakmax said:
We don't know if or how the finished CF shell was checked with NDT, and if any defects found were "repaired".
Given that the hull was wound by a very reputable and experienced manufacturer of composite structures, I still maintain that failures due to a deviation from standard practices
in the carbon fiber section itself are not likely. Certainly possible, but not likely. The most likely failure mode in my opinion is at the adhesive joint, and is due to design errors by the OceanGate team and not by the manufacturer of any one component of the hull.
But, maybe with your experience you can answer a question I've been thinking over... my understanding is that the composite house was given specifications on maximum pressure limits etc to design the composite section against. Also that they are highly experienced and well reputed for filament wound structures, but not for filament-wound structures for high pressure underwater applications. I tend to lay blame at the feet of the OceanGate staff for selecting the wrong material for the application, and then dictating design terms to the composite manufacturer, who essentially just 'followed the drawing'.
Question is, in the world of commercial composite structures, would thorough NDT be expected as part of their in-house quality control process, regardless of whether or not it was specified by the client, or is that the sort of thing that you would expect to only receive if it was directed on plans/by contract?
I have been running on the assumption that any specific porosity/density requirements needed to be directly specified by the OceanGate engineers, and that if the composite hull section was not heavily inspected via ultrasound or whatever, it is simply because the OceanGate team failed to specify quality requirements correctly.