<PAGE>
                                                                    EXHIBIT 4.6


                  AMENDED AND RESTATED SUBORDINATION AGREEMENT

      WHEREAS, Tarpon Industries, Inc. ("Tarpon"), is indebted to the
Undersigned pursuant to Tarpon's 8% Junior Secured Promissory Notes dated April
5, 2004 (the "Subordinated Notes") and to secure its obligations thereunder,
Tarpon has executed and delivered a General Security Agreement dated May_______,
2004 (the "Tarpon Security Agreement");

      WHEREAS, Eugene Welding Co. ("Borrower") guarantied the obligations of
Tarpon in respect of the Subordinated Notes pursuant to a guaranty dated as of
April 26, 2004, and a General Subordinated Security Agreement of even date
therewith (collectively, the "Guaranty Instruments"), and will or may from time
to time hereafter be otherwise indebted to the holders of the Subordinated Notes
in various sums (the Subordinated Notes, the Tarpon Security Agreement, and the
Guaranty Instruments are collectively referred to herein as the "Junior Debt
Instruments");

      WHEREAS, Comerica Bank and the Undersigned are parties to that certain
Subordination Agreement, dated April_____, 2004 (the "Original Agreement"),
pursuant to which, among other things, the Junior Debt and the Undersigned's
Collateral (as defined below) are subordinated to certain indebtedness owing to
Comerica Bank and collateral securing the same;

      WHEREAS, the Undersigned is desirous of having STANDARD FEDERAL BANK N.A.
("Lender") extend and/or continue the extension of credit to Borrower from time
to time as Lender in its sole discretion may determine, which extension of
credit would be used, in part, to pay off the indebtedness owing the Comerica
Bank;

      WHEREAS, in consideration for Lender's extension of such credit and the
payoff by Borrower of its indebtedness to Comerica Bank, and with the consent of
the Undersigned, Comerica Bank has assigned all of its right, title and interest
in and to the Original Agreement to Lender, and Lender's extension and/or
continued extension of such credit is conditioned upon the Junior Debt and the
Undersigned's Collateral being subordinated to the Senior Debt and the Lender's
Collateral (as defined below) in the manner set forth in this amendment and
restatement of the Original Agreement; and

      WHEREAS, the extension and/or continued extension of credit, as aforesaid,
by Lender is necessary or desirable to the conduct and operation of the business
of Borrower, and will inure to the personal and financial benefit of the
Undersigned;

      NOW, THEREFORE, in consideration of the extension and/or continued
extension of credit by Lender to Borrower, as Lender may, in its sole
discretion, determine, and for other good and valuable consideration to the
Undersigned, the receipt and sufficiency of which is hereby acknowledged, the
Undersigned agrees to continue in effect the Original Agreement, as amended and
restated hereby, as to the Lender, the Senior Debt and the Lender's Collateral,
and further agrees to amend and restate the Original Agreement in its entirety
as follows:

      The Undersigned hereby:

                                       1
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            (A)   subordinates the indebtedness of Borrower evidenced by the
      Junior Debt Instruments, as well as any and all other indebtedness for
      borrowed money now or at any time or times hereafter owing by Borrower or
      any successor or assign of Borrower, including without limitation, a
      receiver, trustee, or debtor-in-possession (the term "Borrower" as used
      hereinafter shall include any such successor or assign) to the
      Undersigned, whether such indebtedness is absolute or contingent, direct
      or indirect and howsoever evidenced, including without limitation all
      interest thereon (collectively, the "Junior Debt") to any and all
      indebtedness now or at any time or times hereafter owing by Borrower to
      Lender (whether absolute or contingent, direct or indirect and howsoever
      evidenced, including without limitation all interest thereon, whether or
      not such interest is allowed in a bankruptcy or similar proceeding) and
      all other demands, claims, liabilities or causes of action for which
      Borrower may now or at any time or times hereafter in any way be liable to
      Lender, whether under any agreement, instrument, or document executed and
      delivered or made by Borrower to Lender or otherwise (collectively, the
      "Senior Debt");

            (B)   agrees not to ask for or receive from Borrower any security
      for the Junior Debt, not specifically granted by the Junior Debt
      Instruments; agrees to subordinate all security interests, liens,
      encumbrances and claims, whether now existing or hereafter arising, which
      in any way secure the payment of the Junior Debt (the "Undersigned's
      Collateral") to all security interests, liens, encumbrances and claims,
      whether now existing or hereafter arising, including without limitation
      claims under guaranties of the Senior Debt, which in any way secure the
      payment of the Senior Debt (the "Lender's Collateral"); and agrees that it
      will not take any action to enforce any of its liens or claims on the
      Undersigned's Collateral or otherwise under the Junior Debt Instruments,
      except that upon or after the due date of the Subordinated Notes, the
      Undersigned may upon the non-payment by Tarpon of such Subordinated Notes
      upon or after the due date thereof, (i) institute suit for a money
      judgment to collect any such payments from Tarpon or any other persons
      (other than Borrower) liable for such payments, or (ii) institute suit
      against Tarpon or any other persons (other than Borrower) liable for such
      payments to collect all or any portion of the Subordinated Notes and
      foreclose on any of the Undersigned's Collateral that is owned by Tarpon
      (other than its ownership interest in Borrower) or any other persons
      (other than Borrower) liable for such payments and not owned by Borrower
      or used by Borrower in the ordinary course of its business;

            (C)   agrees that in the event Lender forecloses or realizes upon or
      enforces any of its rights with respect to Lender's Collateral, or
      Borrower sells any of Lender's Collateral in a transaction consented to by
      Lender, the Undersigned shall, upon demand, execute such terminations,
      partial releases and other documents as Lender requests in its sole
      discretion to release the Undersigned's lien and claims upon such Lender's
      Collateral to the extent of Lender's interest therein; agrees that it
      shall have no right to possession of any assets included in the
      Undersigned's Collateral if it is included in the Lender's

                                       2
<PAGE>

      Collateral or is otherwise used by Borrower in the ordinary course of its
      business, whether by judicial action or otherwise, unless and until Lender
      has, in writing, notified the Undersigned that all the Senior Debt has
      been paid in full and all obligations arising in connection therewith have
      been discharged; agrees that it will not contest the validity, perfection,
      priority or enforceability of any lien or security interest now or
      hereafter granted to secure the Senior Debt; and agrees that, as between
      Lender and the Undersigned, the terms of this Subordination Agreement
      shall govern even if all or part of the Lender's claim or the liens or
      security interests securing payment thereof, are avoided, disallowed, set
      aside or otherwise invalidated;

            (D)   agrees to instruct Borrower not to pay, and agrees not to
      accept payment of, or assert, demand, sue for or seek to enforce against
      Borrower, by setoff or otherwise, all or any portion of the Junior Debt or
      the Junior Debt Instruments unless and until Lender has, in writing,
      notified the Undersigned that the Senior Debt has been paid in full and
      all obligations arising in connection therewith have been discharged;
      provided, however, Borrower may make distributions to Tarpon for the
      purpose of, and to the extent necessary for, paying all or any portion of
      the Subordinated Notes or the interest accrued thereon if: (a) the
      Subordinated Notes are due and payable, (b) Tarpon has not yet completed
      the underwritten initial public offering of its common shares pursuant to
      an effective registration statement filed with the United States
      Securities and Exchange Commission, (c) at the time of any such payment
      and immediately thereafter there is no Event of Default nor any event that
      with notice or lapse of time would constitute an Event of Default under
      the agreements and instruments evidencing or relating to the Senior Debt
      (the "Senior Debt Instruments") other than Tarpon's and Borrower's failure
      to have paid when due the Subordinated Notes, other indebtedness due the
      Undersigned or other indebtedness subordinated to Lender under a written
      subordination agreement of even date herewith, (d) Borrower has Excess
      Availability (as defined in the Senior Debt Instruments) of at least
      $1,000,000 immediately after such payment and has an average Excess
      Availability of at least $1,000,000 plus the amount of such payment over
      the period of 90 days ending on the date of such payment, and (e) all
      funds so distributed are used to pay principal and accrued interest on the
      Subordinated Notes;

            (E)   during the continuance of an Event of Default under the Senior
      Debt Instruments of which the Undersigned has actual notice, other than
      Tarpon's and Borrower's failure to have paid when due the Subordinated
      Notes, other indebtedness due the Undersigned or other indebtedness
      subordinated to Lender under a written subordination agreement of even
      date herewith, or in the event of a breach by the Undersigned of its
      obligations hereunder, subrogates Lender to the Junior Debt and the
      Undersigned's Collateral and irrevocably authorizes Lender (i) to collect,
      receive, enforce and accept any and all sums or distributions of any kind
      that may become due, payable or distributable on or in respect of the
      Junior Debt or the Undersigned's Collateral, whether paid directly by
      Borrower or

                                       3
<PAGE>

      paid or distributed in any liquidation, bankruptcy, arrangement,
      receivership, assignment, reorganization or dissolution proceedings or
      otherwise, and (ii) in Lender's sole discretion, to make and present
      claims therefor in, and take such other actions as Lender deems necessary
      or advisable in connection with, any such proceedings, either in Lender's
      name or in the name of the Undersigned; and agrees that, during the
      continuance of an Event of Default under the Senior Debt Instruments of
      which the Undersigned has actual notice, other than Tarpon's and
      Borrower's failure to have paid when due the Subordinated Notes, other
      indebtedness due the Undersigned or other indebtedness subordinated to
      Lender under a written subordination agreement of even date herewith, or
      in the event of a breach by the Undersigned of its obligations hereunder,
      upon the written request of Lender, it will promptly assign, endorse and
      deliver to and deposit with Lender all agreements, instruments and
      documents evidencing the Junior Debt, including without limitation the
      Junior Debt Instruments;

            (F)   agrees to receive and hold in trust for and promptly turn over
      to Lender, in the form received (except for the endorsement or assignment
      by the Undersigned where necessary), any sums at any time paid to, or
      received by, the Undersigned in violation of the terms of this Agreement
      and to reimburse Lender for all costs, including reasonable attorney's
      fees, incurred by Lender in the course of collecting said sums should the
      Undersigned fail to voluntarily turn the same over to Lender as herein
      required. If the Undersigned fails to endorse or assign to Lender any
      items of payment received by the Undersigned on account of the Junior Debt
      or the Undersigned's Collateral to the extent required hereby, the
      Undersigned hereby irrevocably makes, constitutes and appoints Lender (and
      all persons designated by Lender for that purpose) as the Undersigned's
      true and lawful attorney and agent-in-fact, to make such endorsement or
      assignment in the Undersigned's name; and

            (G)   agrees that it shall not modify or amend any agreement,
      instrument or document evidencing or securing the Junior Debt, including
      without limitation the Junior Debt Instruments, without the prior written
      consent of Lender.

      Upon written request by the Undersigned in each instance, Lender will
endeavor to notify the Undersigned of any conditions described in paragraph
(D)(c); however, Lender shall have no obligation to do so and shall not waive
any of its rights or interests if it fails or refuses to do so.

      The Undersigned represents and warrants to Lender that the Undersigned has
not assigned or otherwise transferred the Junior Debt or the Undersigned's
Collateral, or any interest therein to any person or entity, that the
Undersigned will make no such assignment or other transfer thereof, and that all
agreements, instruments and documents evidencing the Junior Debt and the
Undersigned's Collateral will be endorsed with proper notice of this Agreement.
The Undersigned and Borrower will, within ten (10) days following the date
hereof, deliver to Lender a certified copy of the Junior Debt Instruments, as
well as certified copies of all other agreements, instruments and documents
hereafter evidencing any Junior Debt, in each case showing such endorsement. The
Undersigned represents and warrants to Lender that the

                                       4
<PAGE>

outstanding principal amount of Junior Debt evidenced by the Junior Debt
Instruments as of the date of this Agreement is $50,000, plus accrued interest.

      The Undersigned expressly waives all notice of the acceptance by Lender of
the subordination and other provisions of this Agreement and all notices not
specifically required pursuant to the terms of this Agreement, and the
Undersigned expressly waives reliance by Lender upon the subordination and other
provisions of this Agreement as herein provided. The Undersigned consents and
agrees that all Senior Debt shall be deemed to have been made, incurred and/or
continued at the request of the Undersigned and in reliance upon this Agreement.
The Undersigned agrees that Lender has made no warranties or representations
with respect to the due execution, legality, validity, completeness or
enforceability of the documents, instruments and agreements evidencing the
Senior Debt, that Lender shall be entitled to manage and supervise its financial
arrangements with Borrower in accordance with its usual practices, without
impairing or affecting this Agreement, and that Lender shall have no liability
to the Undersigned, and the Undersigned hereby waives any claim which it may now
or hereafter have against Lender arising out of (i) any and all actions which
Lender takes or omits to take (including without limitation actions with respect
to the creation, perfection or continuation of liens or security interests in
any existing or future Lender's Collateral, actions with respect to the
occurrence of an event of default under any documents, instruments or agreements
evidencing the Senior Debt, actions with respect to the foreclosure upon, sale,
release, or depreciation of, or failure to realize upon, any of Lender's
Collateral and actions with respect to the collection of any claim for all or
any part of the Senior Debt from any account debtor, guarantor or other person
or entity) with respect to the documents, instruments and agreements evidencing
the Senior Debt or to the collection of the Senior Debt or the valuation, use,
protection or release of Lender's Collateral (ii) Lender's election in any
proceeding instituted under Chapter 11 of Title 11 of United States Code (11
U.S.C. Section 101 et. seq.) (the "Bankruptcy Code"), of the application of
Section 1111(b)(2) of the Bankruptcy Code, and/or (iii) any borrowing or grant
of a security interest under Section 364 of the Bankruptcy Code by Borrower, as
debtor in possession. Without limiting the generality of the foregoing, the
Undersigned waives the right to assert the doctrine of marshalling with respect
to any of the Lender's Collateral, and consents and agrees that Lender may
proceed against any or all of the Lender's Collateral in such order as Lender
shall determine in its sole discretion.

      The Undersigned agrees that Lender, at any time and from time to time
hereafter, may enter into such agreements with Borrower as Lender may deem
proper extending the time of payment of or renewing or otherwise altering the
terms of all or any of the Senior Debt or affecting any of Lender's Collateral,
and may sell or surrender or otherwise deal with any of Lender's Collateral, and
may release any balance of funds of Borrower with Lender, without notice to the
Undersigned and without in any way impairing or affecting this Agreement.

      This Agreement shall be irrevocable and shall constitute a continuing
agreement of subordination and shall be binding on the Undersigned and its
heirs, personal representatives, successors and assigns, and shall inure to the
benefit of Lender, its successors and assigns until Lender has, in writing,
notified the Undersigned that all of the Senior Debt has been paid in full and
all obligations arising in connection therewith have been discharged. Lender may
continue, without notice to the Undersigned, to lend monies, extend credit and
make other

                                       5
<PAGE>

accommodations to or for the account of Borrower on the faith hereof. The
Undersigned hereby agrees that all payments received by Lender may be applied,
reversed, and reapplied, in whole or in part, to any of the Senior Debt, without
impairing or affecting this Agreement.

      The Undersigned hereby assumes responsibility for keeping itself informed
of the financial condition of Borrower, any and all endorsers and any and all
guarantors of the Senior Debt and the Junior Debt and of all other circumstances
bearing upon the risk of nonpayment of the Senior Debt and the Junior Debt that
diligent inquiry would reveal, and the Undersigned hereby agrees that Lender
shall have no duty to advise the Undersigned of information known to Lender
regarding such condition or any such circumstances or to undertake any
investigation not a part of its regular business routine. If Lender, in its sole
discretion, undertakes, at any time or from time to time, to provide any
information of the type described herein to the Undersigned, Lender shall be
under no obligation to subsequently update any such information or to provide
any such information to the Undersigned on any subsequent occasion.

      The Undersigned hereby authorizes Lender to file and/or record UCC
financing statements for the purpose of providing notice to third parties of the
existence and effect of this Agreement.

      No waiver shall be deemed to be made by Lender of any of its rights
hereunder unless the same shall be in writing signed on behalf of Lender and
each such waiver, if any, shall be a waiver only with respect to the specific
matter or matters to which the waiver relates and shall in no way impair the
rights of Lender or the obligations of the Undersigned to Lender in any other
respect at any other time.

      THIS AGREEMENT SHALL BE GOVERNED AND CONTROLLED BY THE INTERNAL LAWS OF
THE STATE OF MICHIGAN.

      To induce Lender and the Undersigned to accept this Agreement, the
Undersigned and the Lender irrevocably agree that ALL ACTIONS OR PROCEEDINGS IN
ANY WAY, MANNER OR RESPECT, ARISING OUT OF OR FROM OR RELATED TO THIS AGREEMENT
SHALL BE LITIGATED IN COURTS HAVING SITUS WITHIN THE COUNTY OF OAKLAND, STATE OF
MICHIGAN. THE UNDERSIGNED AND LENDER HEREBY CONSENT AND SUBMIT TO THE
JURISDICTION OF ANY LOCAL, STATE OR FEDERAL COURTS LOCATED WITHIN SAID COUNTY
AND STATE. THE UNDERSIGNED AND THE LENDER HEREBY WAIVE ANY RIGHT THEY MAY HAVE
TO TRANSFER OR CHANGE THE VENUE OF ANY LITIGATION BROUGHT AGAINST THE
UNDERSIGNED OR LENDER IN ACCORDANCE WITH THIS PARAGRAPH.

      THE UNDERSIGNED AND LENDER HEREBY WAIVE ALL RIGHTS TO TRIAL BY JURY IN ANY
ACTION OR PROCEEDING WHICH PERTAINS DIRECTLY OR INDIRECTLY TO THIS AGREEMENT.

                         (signatures on following pages)

                                       6
<PAGE>

      IN WITNESS WHEREOF, this Agreement has been executed as of this _th day of
August, 2004.

                                        /s/ Anand Dhanda
                                        -----------------------------------
                                        Anand Dhanda

                                        Address:
                                                       Anand M. Dhanda, MD
                                                 8028 Ritchle Highway Suite 114
                                                       Pasadena, MD 21122
                                                         (410) 761-4404
                                                         Fax: 761-5484

                          ACKNOWLEDGMENT OF SIGNATURES

Witness: /s/ Theresa Kurtz
         --------------------------
         By: THERESA KURTZ

                                       7
<PAGE>

                               BORROWER'S CONSENT

      Borrower hereby consents to the foregoing Agreement (and the terms
thereof) and agrees to abide thereby and to keep, observe and perform the
several matters and things therein intended to be kept, observed and performed
by it, and specifically agrees not to make any payments contrary to the terms of
said Agreement.

      A breach of any of the terms and conditions of this consent shall
constitute an "Event of Default" under the Loan and Security Agreement dated of
even date herewith between Borrower and Lender.

                                 BORROWER:

                                 EUGENE WELDING CO.

                                 By: /s/ Charles A. Vanella
                                     -------------------------------------------
                                     Charles A. Vanella, Chief Executive Officer

STATE OF MICHIGAN )
                  )SS.
COUNTY OF WAYNE   )

      I, Bonnie L. Schneider, a Notary Public in and for the state and county
aforesaid do hereby certify that before me this day personally appeared Charles
A. Vanella known to me to be the Chief Executive Officer of the corporation that
executed the foregoing consent and acknowledged to me that he (they) executed
and delivered the foregoing consent for and on behalf of the corporation, for
the uses set forth therein.

      IN WITNESS WHEREOF, I have hereunto set my hand and official seal this
11th day of August, 2004.

                                        /s/ Bonnie L. Schneider
                                        -------------------------------------
                                        Notary Public
                                        Acting In Wayne County, Michigan
                                        My Commission Expires: 12/30/07

                                                 Bonnie L. Schneider
                                         Notary Public, Wayne County, Michigan
                                        My Commission Expires: December 30, 2007

                                       8
<PAGE>

                                TARPON'S CONSENT

      Tarpon hereby consents to the foregoing Agreement (and the terms thereof)
and agrees to abide thereby and to keep, observe and perform the several matters
and things therein intended to be kept, observed and performed by it, and
specifically agrees not to make or receive any payments contrary to the terms of
said Agreement.

      A breach of any of the terms and conditions of this consent shall
constitute an "Event of Default" under the Loan and Security Agreement dated of
even date herewith between Borrower and Lender.

                                 TARPON:

                                 TARPON INDUSTRIES, INC.

                                 By /s/ Charles A. Vanella
                                    -------------------------------------------
                                    Charles A. Vanella, Chief Executive Officer

STATE OF MICHIGAN )
                  )SS.
COUNTY OF WAYNE   )

      I, Bonnie L. Schneider, a Notary Public in and for the state and county
aforesaid, do hereby certify that before me this day personally appeared Charles
A. Vanella known to me to be the Chief Executive Officer of the corporation that
executed the foregoing consent and acknowledged to me that he (they) executed
and delivered the foregoing consent for and on behalf of the corporation, for
the uses set forth therein.

      IN WITNESS WHEREOF, I have hereunto set my hand and official seal this
11th day of August, 2004.

                                        /s/ Bonnie L. Schneider
                                        -----------------------------------
                                        Notary Public
                                        Acting In Wayne County, Michigan
                                        My Commission Expires: 12/30/07

                                                    Bonnie L. Schneider
                                         Notary Public, Wayne County, Michigan
                                        My Commission Expires: December 30, 2007

                                       9
<PAGE>

                                LENDER'S CONSENT

      Lender hereby consents to the foregoing Agreement (and the terms thereof).

                                             LENDER:

                                             STANDARD FEDERAL BANK N.A.

                                             By  /s/ Greg Boller
                                                 -------------------------------
                                                 Greg Boller, Vice President

STATE OF MICHIGAN )
                  )SS.
COUNTY OF WAYNE   )

      I, Bonnie L. Schneider, a Notary Public in and for the state and county
aforesaid, do hereby certify that before me this day personally appeared Greg
Boller, known to me to be the Vice President of the bank that executed the
foregoing consent and acknowledged to me that he (they) executed and delivered
the foregoing consent for and on behalf of the corporation, for the uses set
forth therein.

      IN WITNESS WHEREOF, I have hereunto set my hand and official seal this
11th day of August, 2004.

                                        /s/ Bonnie L. Schneider
                                        -----------------------------------
                                        Notary Public
                                        Acting In Wayne County, Michigan
                                        My Commission Expires: 12/30/07

                                                   Bonnie L. Schneider
                                          Notary Public, Wayne County, Michigan
                                        My Commission Expires: December 30, 2007