No apprentice agreement under this chapter shall be effective until approved by the Commissioner. Every apprentice agreement shall be signed by the employer, or by an association of employers or an organization of employees and by the apprentice and, if the apprentice is a minor, by the minor's father; provided, that if the father be dead or legally incapable of giving consent, then by the guardian of the minor. Where a minor enters into an apprentice agreement under this chapter for a period of training extending into his majority, the apprentice agreement shall likewise be binding for such a period as may be covered during the apprentice's majority.