1 Exhibit 23(a) Consent of Deloitte & Touche LLP, Independent Auditors to Registrant 30 2 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in this Registration Statement of Core Materials Corporation on Form S-8 of our report dated March 2, 1998, appearing in the Annual Report on Form 10-K of Core Materials Corporation for the year ended December 31, 1997. /s/ DELOITTE & TOUCHE LLP - -------------------------- DELOITTE & TOUCHE LLP Chicago, Illinois August 6, 1998 31