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                       FOURTH AMENDMENT TO LOAN AGREEMENT

            This FOURTH AMENDMENT TO LOAN AGREEMENT ("Amendment") dated August
8, 1997 is made by and among APOGEE, INC., a Delaware corporation ("Apogee"),
and each Subsidiary identified on the attached Schedule 6.1 (c) (collectively,
the "Borrowing Subsidiaries" and together with Apogee, the "Borrowers" and
individually, a "Borrower") and PNC BANK, NATIONAL ASSOCIATION, a national
banking association (the "Bank").

            Reference is made to the Revolving Credit Agreement dated as of
April 11, 1996 by and between the Borrowers and the Bank, as amended on June 21,
1996, November 1, 1996 and March 11, 1997 (the "Agreement") pursuant to which
the Bank made available to the Borrowers a $15,000,000 revolving credit
facility. The obligations under the Agreement and the Loan Documents were
evidenced by the Borrowers' Note payable to the Bank. (Capitalized terms used
herein not otherwise defined shall have the meanings provided for in the
Agreement.)

            NOW, THEREFORE, in consideration of the foregoing and for other
consideration, the receipt and sufficiency of which is hereby acknowledged, the
parties hereto, intending to be legally bound, hereby agree as follows:
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            1. Amendment to Agreement.

            (a) The Agreement is hereby amended by amending the definition of
"Expiration Date" by substituting for the date set forth therein the date
"November 30, 1998" and the Loan Documents, including the "Revolving Credit
Note" are likewise amended to reflect such date.

            2. Miscellaneous.

            (a) Recognizing and in consideration of the Bank's agreement to the
amendments herein set forth, the Borrowers hereby waive and release the Bank and
its officers, attorneys, agents, and employees from any liability, suit, damage,
claim, loss or expense of any kind or nature whatsoever and howsoever arising
out of or relating to the Bank's acts or omissions with respect to the Revolving
Credit Loans. The Borrowers further hereby agree to indemnify and hold the Bank
and its officers, attorneys, agents and employees harmless from any loss,
damage, judgment, liability or expense (including counsel fees) suffered by or
rendered against the Bank or any of them on account of anything arising out of
the Revolving Credit Note, the Credit Agreement, this Agreement, the Loan
Documents or any other document delivered pursuant thereto up to and including
the date hereof.

            (b) All of the terms, conditions, provisions and covenants in the
Note, the Agreement, the Loan Documents, and all other documents delivered to
the Bank in connection
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with any of the foregoing documents and obligations secured thereby shall remain
unaltered and in full force and effect except as modified by this Amendment.

            (c) The Borrowers agree to pay all of the Bank's expenses incurred
in connection with the preparation of this Amendment and the transactions
contemplated by this Amendment, including without limitation, the reasonable
fees and expenses of the Bank's counsel.

            (d) This Amendment shall be governed by and construed in accordance
with the laws of the Commonwealth of Pennsylvania.

            (e) Each and every one of the terms and provisions of this Amendment
shall be binding upon and shall inure to the benefit of the Borrowers and the
Bank and their respective successors and assigns.

            (f) This Amendment may be executed in one or more counterparts, each
of which shall be deemed to be an original as against any party whose signature
appears thereon, and all of which shall constitute but one and the same
instrument.

            (g) Apogee represents and warrants that all of its subsidiaries are
listed on the attached Schedule 6.1(c).
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            IN WITNESS WHEREOF, the parties hereto have caused this Amendment to
be executed by their respective officers "hereunto duly authorized as of the day
and year first above written.

                                          APOGEE, INC., a Delaware
                                          corporation, and each of the other
                                          Borrowers and Guarantors listed on
                                          Schedule 6.1(c)


                                          By:
                                             -------------------------------
                                          [Name],
                                          the                    [Title] of
                                              -------------------
                                          each Borrowers and Guarantors
                                          listed on Schedule 6.1(c),

                                                      -and-

                                          PNC BANK, NATIONAL ASSOCIATION


                                          By:
                                             --------------------------------

                                          Name:
                                               ------------------------------

                                          Title:
                                                -----------------------------