A method for repairing a composite structure using pre-cured plugs. In accordance with one method, composite material is removed from a first composite laminate to form a cavity bounded by a tapered internal surface that extends from an opening at an outer mold line surface of the first composite laminate. In addition, a second composite laminate is machined to form a plug having a tapered surface. Then the plug is placed so that the tapered surface of the plug opposes the tapered internal surface of the first composite laminate. Thereafter, the tapered surface of the plug is bonded to the tapered internal surface of the first composite laminate. Optionally, a hole is drilled in the plug for receiving a fastener.

Matrix composite component repair processes are disclosed. The matrix composite repair process includes applying a repair material to a matrix composite component, securing the repair material to the matrix composite component with an external securing mechanism and curing the repair material to bond the repair material to the matrix composite component during the securing by the external securing mechanism. The matrix composite component is selected from the group consisting of a ceramic matrix composite, a polymer matrix composite, and a metal matrix composite. In another embodiment, the repair process includes applying a partially-cured repair material to a matrix composite component, and curing the repair material to bond the repair material to the matrix composite component, an external securing mechanism securing the repair material throughout a curing period, In another embodiment, the external securing mechanism is consumed or decomposed during the repair process.

A seal application method of applying a sealing material in a narrow portion serving as a hollow portion being formed inside a target object and communicating with outside, the seal application method including: arranging the target object such that a target surface inside the narrow portion faces downward; forming a brush coat by inserting into the narrow portion a brush coating device including at an upper portion thereof a brush portion with the sealing material adhered thereto, pressing the brush portion upward and rubbing the brush portion against the target surface, thereby applying the sealing material to the target surface; after forming the brush coat, inverting the target object such that the target surface faces upward; and, after inverting the target object, forming an edge seal being thicker than the brush coat by inserting an edge sealing device into the narrow portion and causing the edge sealing device to apply the sealing material onto the brush coat from above.

A repair solution for a wind turbine blade is described. The repair solution includes the application of a layer of viscous coating material to the section of the blade to be repaired, which is cured to form a repaired surface. The layer of viscous coating material may be temporarily covered during the curing process using a film of Low Surface Energy material, to prevent defects in the repaired surface from dust, insects, etc. Additionally or alternatively, a temporary shield may be erected adjacent the curing layer of coating material, to allow for the control of the temperature and/or humidity levels of the region adjacent the curing material, to provide for more effective control of the curing process and to allow for repairs to be carried out for a wider process window.

Methods for repairing thermoplastic composite parts are presented. A heating element impregnated with a thermoplastic material is placed onto a repair area of a thermoplastic composite part. The thermoplastic material of the heating element is adhered to the repair area by generating heat in the heating element from current applied to the heating element. A repair patch is placed over the heating element after adhering the heating element to the repair area. A current is applied to the heating element to heat the repair patch to a patch processing temperature.

A multi-part kit system may be used to repair damaged products used in industrial applications, comprising a part A which includes (A1) MDI prepolymer, (A2) fumed silica, and (A3) plasticizer; a part B which includes (B1) hydroquinone di-(2-hydroxyethyl)ether and (B2) plasticizer; and a part C which includes (C1) polyol, (C2) optionally, catalyst, and (C3) optionally, plasticizer.