1 EXHIBIT 23 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in Registration Statement No. 333-29203 of Core Materials Corporation on Form S-8 of our report dated February 16, 1999, appearing in the Annual Report on Form 10-K of Core Materials Corporation for the year ended December 31, 1998. Deloitte & Touche LLP Chicago, Illinois March 25, 1999