<PAGE>   1
                                                                  Exhibit 4.3(c)
                      SECOND AMENDMENT TO CREDIT AGREEMENT

         THIS SECOND AMENDMENT TO CREDIT AGREEMENT (this "AMENDMENT"), dated as
of February 18, 1997, is entered into among EASCO CORPORATION ("BORROWER"), the
various financial institutions which are parties hereto ("LENDERS") and BANK OF
AMERICA ILLINOIS, as agent ("AGENT"),

                              W I T N E S S E T H:

         WHEREAS, Borrower, Lenders and Agent are parties to a Credit Agreement
dated as of March 18, 1994 as amended and modified by a First Amendment dated as
of January 31, 1995, (the "CREDIT AGREEMENT"); and

        WHEREAS, the parties hereto desire to amend the Credit Agreement in
certain respects as hereinafter set forth;

         NOW, THEREFORE, in consideration of the premises and mutual agreements
herein contained, the parties hereto agree as follows:

SECTION 1.  DEFINED TERMS.  Terms defined in the Credit Agreement and not
otherwise defined herein are used herein as therein defined.

SECTION 2.  AMENDMENTS TO CREDIT AGREEMENT.

         The Credit Agreement is amended as follows:

SECTION 2.1. AMENDMENT OF SECTION 2.1.2. Section 2.1.2(i) is amended by deleting
"$55,000,000" and substituting "$40,000,000 (provided, however, that such amount
shall be reduced to $30,000,000 during any period when the Borrower is not in
full compliance with the financial covenants in Sections 8.24 (a), (b) and (c),
as such covenants existed prior to February 18, 1997)" in place thereof.

SECTION 2.2. AMENDMENT OF SECTION 8.2.4(a). Section 8.2.4(a) is amended by
adding the following proviso at the end thereof:

"Notwithstanding the foregoing, the Fixed Charge Coverage Ratio shall not be
applicable during the period from the fourth Fiscal Quarter, 1996 through the
last day of the third Fiscal Quarter, 1997."

SECTION 2.3. AMENDMENT OF SECTION 8.2.4(b). Section 8.2.4(b) is amended by
adding the following to the end thereof:

"Notwithstanding the foregoing, the Consolidated Leverage Ratio shall

<PAGE>   2
not be applicable during the period from the fourth Fiscal Quarter, 1996
through the last day of the third Fiscal Quarter, 1997."

SECTION 2.4. AMENDMENT OF SECTION 8.2.5. Section 8.2.5 is amended by adding the
following to the end thereof:

"Notwithstanding the foregoing, throughout the Fiscal year of 1997, additional
investments or acquisitions made after February 1, 1997 in the aggregate in
excess of $5,000,000 shall be permitted only upon the prior consent of the
Required Lenders."

SECTION 2.5. ADDITION OF NEW SECTION 8.1.13. A new Section 8.1.13 is added to
the Credit Agreement as follows:

"SECTION 8.1.13 MINIMUM CONSOLIDATED EBITDA. The Borrower will maintain a
cumulative Consolidated EBITDA with respect to the cumulative periods of its
1997 Fiscal Year of at least $3,900,000 through the last day of the first Fiscal
Quarter, 1997; $10,900,000 through the last day of the second Fiscal Quarter,
1997 and $17,500,000 through the last day of the third Fiscal Quarter, 1997."

SECTION 2.6. AMENDMENT TO DEFINITIONS. The definition of "Borrowing Base" in
Schedule I to the Credit Agreement is hereby amended by deleting "80%" and
substituting "70%" in place thereof and by further deleting "60%" and
substituting "50%" in place thereof.

SECTION 2.7. AMENDMENT TO DEFINITION OF NON-USE FEE PERCENTAGE. The definition
of "Non-Use Fee Percentage" in Schedule I to the Credit Agreement is hereby
amended by deleting the percentages in the columns entitled "Non-Use Fee
Percentage" and substituting the following in place thereof:

"Non-Use Fee Percentage

 .500%
 .500%
 .375%
 .250%
 .250%"

SECTION 2.8. AMENDMENT TO DEFINITION OF APPLICABLE MARGIN. The following is
added to the end of the table referenced in the definition of "Applicable
Margin" in Schedule I of the Credit Agreement:

     "Notwithstanding the foregoing, the following pricing
<PAGE>   3
grid shall be effective throughout 1997:

<TABLE>
<CAPTION>
          Consolidated Leverage Ratio                     Applicable Margin

                                                       Base                           Letter of
                      Greater       Less than OR       Rate          Eurodollar      Credit Face
     Level             Than           Equal to         Loans           Loans         Amount Fee
     -----          -----------     ------------       ------        ----------      -----------
<S>                <C>             <C>                <C>           <C>             <C>
       I             5.0 to 1.0                        0.625%           1.875%          1.875%
      II             4.0 to 1.0      5.0 to 1.0        0.375%           1.625%          1.625%
      III            3.0 to 1.0      4.0 to 1.0        0.125%           1.375%          1.375%
      IV             2.0 to 1.0      3.0 to 1.0         0.00%           1.125%          1.125%
       V                             2.0 to 1.0         0.00%           0.875%          0.875%
</TABLE>

SECTION 3. REPRESENTATIONS AND WARRANTIES. Borrower hereby represents and
warrants to Agent and Lenders, as of the date of the actual execution of this
Amendment, that:

         3.1. DUE AUTHORIZATION, ETC. The execution and delivery by it of this
Amendment and the Replacement Note and the performance by it of its obligations
under the Credit Agreement, and the Replacement Note are duly authorized by all
necessary corporate action, do not require any filing or registration with or
approval or consent of any governmental agency or authority, do not and will not
conflict with, result in any violation of or constitute any default under any
provision of its Organic Documents or the Organic Documents of any of its
Subsidiaries or any material agreement or other document binding upon or
applicable to it or any of its Subsidiaries (or any of their respective
properties) or any material law or governmental regulation or court decree or
order applicable to it or any of its Subsidiaries, and will not result in or
require the creation or imposition of any Lien on nay of its properties or the
properties of any of its Subsidiaries pursuant to the provisions of any
agreement binding upon or applicable to it or any of its Subsidiaries.

         3.2. VALIDITY. This Amendment and the Replacement Note have been duly
executed and delivered by Borrower and, together with the Credit Agreement (as
amended hereby), are legal, valid and binding obligations of Borrower,
enforceable against Borrower in accordance
<PAGE>   4
with their respective terms subject, as to enforcement only, to bankruptcy,
insolvency, reorganization, moratorium or similar laws affecting the
enforceability of the rights of creditors generally and by general principles
of equity (regardless of whether enforcement is sought  in a proceeding at
equity or law).

         3.3. NO DEFAULT; REPRESENTATIONS AND WARRANTIES. After giving effect to
the Amendment as set forth herein, (A) No Event of Default or Default has
occurred and is continuing and (B) the representations and warranties contained
in Article VII of the Credit Agreement are true and correct, except to the
extent (a) that such representations and warranties solely relate to an earlier
date or (b) changed by circumstances permitted by the Credit Agreement.

SECTION 4. CONDITIONS PRECEDENT. The amendments to the Credit Agreement set
forth in Section 2 of this Amendment shall become effective as follows:

     4.1. CONDITIONS. The amendments contained in Sections 2.1 and 2.3 of this
Amendment shall become effective on such date when all of the following
conditions precedent shall have been satisfied:

          (a) RECEIPT OF DOCUMENTS. Agent shall have received all of the
     following, each in form and substance satisfactory to Agent:

               (i) AMENDMENT. A counterpart original of this Amendment duly
          executed by Borrower;

               (ii) RESOLUTIONS, ETC. A certificate of the secretary or an
          assistant secretary of Borrower dated the date of the execution of
          this Amendment or such other date as shall be acceptable to Agent;

               (iii) AMENDMENT FEE. Evidence of payment from the Borrower to the
          Agent of the amendment fee for the account of each Lender, such fee to
          be equal to 0.10% of the amount of such Lender's Commitment (as of the
          date of this Amendment, after giving effect hereto) and to be
          distributed by the Agent to each Lender upon the effectiveness of this
          Amendment; and

               (iv) OTHER. Such other documents as Agent may reasonably request.

          (b) NO DEFAULT. No Event of Default or Default shall have occurred and
     be continuing, after giving effect to this Amendment.
<PAGE>   5
SECTION 5.  MISCELLANEOUS.

         5.1. DOCUMENTS REMAIN IN EFFECT. Except as amended and modified by this
Amendment, the Credit Agreement and the other Credit Documents, including but
not limited to the Security Agreement, remain in full force and effect and
Borrower hereby ratifies, adopts and confirms its representations, warranties,
agreements and covenants contained in, and obligations and liabilities under,
the Credit Agreement and the other Credit Documents, including but not limited
to the Security Agreement.

         5.2. REFERENCE TO CREDIT AGREEMENT. On and after the Effective Date,
each reference in the Credit Agreement to "this Agreement," "hereunder,"
"herein" or words of like import, and each reference to the "Credit Agreement"
in the Replacement Note and in any Credit Document, or other agreements,
documents or other instruments executed and delivered pursuant to the Credit
Agreement, shall mean and be a reference to the Credit Agreement, as amended
herein.

         5.3. HEADINGS. Headings used in this Amendment are for convenience of
reference only, and shall not affect the construction of this Amendment.

         5.4. COUNTERPARTS. This Amendment may be executed in any number of
counterparts, and by the parties hereto on the same or separate counterparts,
and each such counterpart, when executed and delivered, shall be deemed to be an
original, but all such counterparts shall together constitute but one and the
same Amendment. One or more executed counterparts of this Amendment or any
document or instrument related hereto may be delivered by telecopier, with the
intention that they shall have the same effect as an original executed
counterpart hereof or thereof. Any party hereto delivering an executed
counterpart of this Amendment or any related document or instrument by
telecopier shall promptly provide an original of such counterpart to Agent.

         5.5. EXPENSES. Borrower agrees to pay on demand all costs and expenses
of Agent (including reasonable fees, charges and disbursements of Agent's
attorneys) in connection with the preparation, negotiation, execution, delivery
and administration of this Amendment and all other instruments or documents
provided for herein or delivered or to be delivered hereunder or in connection
herewith. In addition, Borrower agrees to pay, and save Agent and Lenders
harmless from all liability for, any stamp or other taxes
<PAGE>   6
which may be payable in connection with the execution or delivery of this
Amendment, the borrowings under the Credit Agreement, and the execution and
delivery of any instruments or documents provided for herein or delivered or to
be delivered hereunder or in connection herewith. All obligations provided in
this Section 5.5 shall survive any termination of this Amendment or the Credit
Agreement.

         5.6. GOVERNING LAW. THIS AMENDMENT SHALL BE A CONTRACT MADE UNDER AND
GOVERNED BY THE INTERNAL LAWS OF THE STATE OF ILLINOIS WITHOUT REGARD TO ITS
PRINCIPLES OF CONFLICTS OF LAW. Wherever possible each provision of this
Amendment shall be interpreted in such manner as to be effective and valid under
applicable laws, but if any provision of this Amendment shall be prohibited by
or invalid under such laws, such provisions shall be ineffective only to the
extent of such prohibition or invalidity, without invalidating the remainder of
such provision or the remaining provisions of this Amendment.

         5.7. SUCCESSORS. This Amendment shall be binding upon Borrower,
Lenders, Agent and their respective permitted successors and assigns, and shall
inure to the benefit of Borrower, Lenders, Agent and their respective permitted
successors and assigns.

         5.8. PERCENTAGE. After giving effect to the decrease in the Total
Commitment Amount in Section 2.1.1 of this Amendment, each Lender's
Commitment and Percentage shall be as shown beneath such Lender's signature
on the signature page to this Amendment.

<PAGE>   7
         IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
executed by their respective officers thereunto duly authorized and delivered at
Chicago, Illinois as of the date first above written.

                                         EASCO CORPORATION

                                         By:   /s/ Terry D. Smith
                                               ---------------------------------
                                         Title: Executive Vice President & CFO
                                                --------------------------------

                                         BANK OF AMERICA ILLINOIS,
                                         individually and as Agent

                                         By:   /s/ Lynn Stetson
                                               ---------------------------------
                                         Title: Managing Director
                                                --------------------------------

                                         Commitment:  $15,272,727.27
                                         Percentage:   .3818181818%

                                         PNC BANK, N.A.

                                         By:   /s/ David Williams
                                               ---------------------------------
                                         Title: Vice President
                                                --------------------------------

                                         Commitment:  $13,818,181.82
                                         Percentage:   .3454545454%

                                         NATIONAL CITY BANK

                                         By:   /s/ Michael P. McCuen
                                               ---------------------------------
                                         Title: Vice President
                                                --------------------------------

                                         Commitment:  $10,909,090.91
                                         Percentage:   .2727272727%