What you are describing is associated with excess primer thickness. Primer thickness should be .00007" to .00012". Too thin and the primer will not cure, too thick and you get "tiger striping" peel failures with very low results.
Shear results are not affected by thick primer but peel...
ASTM D2651 provides steps for preparing a surface for bonding. In the case of copper the recommended procedure is:
1) Degrease
2) Immerse for 1-2 minutes at 77F (25C) in a solution of
42% Aqueous FeCl2 soln. - 15 pbw
Conc. HNO3 (s.g. 1.41) - 30 pbw
DI water - 197 pbw
3) Rinse in cold...
I agree with wes616 that vapor degreasing is the best way to clean dirty core but if the core is kept clean it is ready to bond to straight from the vendor. It is extremely rare for a sandwich structure bond to fail as a result of the core pullng out of the adhesive.
What is most important...
Correct, the Faraday cage effect not being influenced by it's location to the surface.
But, the depth of the conductive LSP material is very important in terms of how concentrated the strike is on the surface of the laminate.
As the conductive layer gets further from the laminate surface...
Compositepro, unlike expanded foils, the mesh products are often bronze. The mesh is also commonly used with matrix resins instead of adhesives. I don't recommend either of these situations but it is often the case - mostly in Europe. Boeing tends to use expanded foils as do most other US...
Like all other epoxy resins, PR520 does shrink during gel. With a very stiff tool this can cause cavitation but if the tool is flexible enough (most tools are) the tool will deform to allow the shrinkage to occur.
You are probably seeing more loss of thickness in the center of the panel as...
If the part count is high pultrusion is the best way forward. If the part count is not in the hundreds I would consider a vacuum molding process or press molding with prepreg.
I'm surprised no one has suggested using a tile saw for these cuts. In this particular situation the 1 meter length might cause some difficulty but provided that can be managed a low-cost tile saw provides an excellent quality of cut at the fastest possible feed rates without overheating the...
Although the phenolic recommendation will provide adequate temperature capability I doubt that you will be able to create a water-tight structure without 200 psi or better during cure.
There are a handful of epoxy resins that offer 400F Tg's after cure/postcure. These offer the best...