Having done this before, I suggest:
- Measure the dimensions of the original foam lining sheets, and make note of how the sheets are cut and fit in the interior.
- Use a paint scraper to remove as much of the foam and dried adhesive as possible. It's OK to leave behind firmly-attached adhesive: It will provide a good-enough base for new adhesive, but any left-behind foam will provide poor footing for the new foam. 3M General Purpose Adhesive Remover (available in quarts) will remove foam crusts and adhesive. Don't go crazy. Wear an organic fume respirator - they're inexpensive, and save your health.
- Buy medium-density polyurethane closed-cell foam sheets in the original thickness used in your case. I fell into some suitable stock courtesy of a friend, so I don't have a supplier name handy. Buy locally if you can, to save shipping (especially if you need 1" or 2" thick pieces that can't be rolled up.) Absent that, a Google of "discount foam packaging" yielded http://www.foampackagingcompany.com/polyethylene-foam.html (and they have a 10% "recession discount" running, discount code RECESSION09). By quizzing some of these outfits you can learn what the best value is for your application. You probably don't need high-end stuff like Ethafoam.)
Then it's measure (twice), cut, trial fit, and glue. For thicker foam, I would lay out the cuts on the foam using masking tape, free-hand an initial shallow cut using a box-cutter blade, and finish each cut in several passes using a sharp, wide, long blade - like a thin chef's knife or santoku. Trying to use a straightedge on foam never worked out for me - it always shifted during cutting. If you dimension the pieces just a bit larger that will help you later compensate for uneven cuts and underestimation of dimensions when assembling and gluing. For the best edge, avoid sawing.
For adhesive, 3M "77" is fine. I'm sure 3M makes one or more specialty adhesives for bonding poly foam to any surface, if you care to chase one down. Another option is to buy foam having an adhesive face, but that's certainly more expensive than buying regular foam.
Sorry if this is more info that you asked for, but that's my nature. :roll:
Happy refurbishing!
