Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. spudpeeler

    Metal bonding issues

    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...
  2. spudpeeler

    Copper foil to fiberglass or carbon fiber bonding

    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...
  3. spudpeeler

    How to bond aluminium honeycomb

    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...
  4. spudpeeler

    Lightning Strike Protection For Composite Structure

    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...
  5. spudpeeler

    Lightning Strike Protection For Composite Structure

    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...
  6. spudpeeler

    Shrinkage of flat RTM plaques...

    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...
  7. spudpeeler

    Pultrusion or Vacuum injection moulding?

    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.
  8. spudpeeler

    Cutting thick carbon fibre sheet

    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...
  9. spudpeeler

    High temperature resin options

    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...
Back
Top