I'm in the middle of doing mine and found the secret to cleaning off the base. I wired brushed the old foam off, manual brush that is, and took the remaining glue off with spray brake cleaner. I sprayed a small section at a time and used a clean wire brush to wire off the adhesive. It took it back to bare cardboard or whatever that stuff is. The lady at Hancocks Fabric said she's done many of them and uses only 3m 900 super strength spray adhesive. I'll let you know how it works out.