Steve, When I worked at a shop that made metal core boards did that type of process. Covered the entire surface with a metal powder and laminated in the press. This filled all the holes in the metal core. Next they used a surface planer to sand the excess resin from the metal core surface. They laminated cores to both sides, drilled and copper plated so the holes passed through the epoxy fill in the metal core. I found this on line: http://compounds.sbna-inc.com/datasheets/Epoxy%20-%20Short%20Glass%20Fiber/X-28057-2HT%20Hole%20Fill%20Grade.pdf Chuck Charles W. Brummer | 3M Manufacturing Engineer 3M Electronic Solutions Division 3M Canoga Park, 8357 Canoga Ave. | Canoga Park, CA 91304 Office: 818 734 4930 [log in to unmask] | www.3M.com This message (including any attachments) may contain material, non-public information or proprietary information and is for the intended recipients only. If you are not the intended recipient, you should notify the sender and delete this message. Any disclosure, copying, or use of this information is strictly prohibited and may subject you to legal liability. From: Steven Kelly <[log in to unmask]> To: <[log in to unmask]> Date: 09/11/2013 07:07 AM Subject: [TN] Metal stiffeners Sent by: TechNet <[log in to unmask]> Good Morning All. I am looking for a way to fill up some holes in a metal stiffener such that a) the surface will be very flush b) I can still go through a press cycle to bond the stiffeners onto the flex. Thanks. Steve Kelly If the recipient to whom this e-mail is sent has an NDA with PFC Flexible Circuits Limited this e-mail is considered confidential and is subject to any NDA agreements between the respective parties. See PFC on "How It's Made`` coming soon on the Discovery Channel! ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________