I am planning to make a composite test piece using 4130 N steel sheets, .025 thickness, bonded to a foam core using a room temperature cure epoxy, Any suggestions on preparing the steel surface would be appreciated.
For maximum strength the steel needs to be cleaned to white condition by etching then drying or glass bead blasting.
4130 will flash rust if any moisture is present, this will reduce your bond strength.
B.E.