Method for masking cooling holes and device for using in a masking process for masking cooling holes

A method of masking cooling holes of a turbine component for a coating process, comprising:

• filling the plurality of cooling holes with a masking material;
• and
• hardening the masking material,
• wherein water is filled in the plurality of cooling holes as the masking material and the hardening is done by freezing the water to water ice, and
• wherein the component includes an external surface to be coated, an internal cavity including an opening towards an outside of the component, and the plurality of cooling holes extending from the internal cavity to the external surface.

A method of coating an external surface of a turbine component, comprising:

• masking a plurality of cooling holes of the turbine component, the masking comprising:
• filling the plurality of cooling holes with a masking material, and
• hardening the masking material;
• coating the external surface thereby depositing coating material onto water ice in the plurality of cooling holes forming a plurality of coating bridges that bridge the plurality of cooling holes;
• removing the water ice after the coating is deposited by melting the coating and draining the melted water ice;
• and
• removing the plurality of coating bridges by applying a pressure pulse to the plurality of cooling holes through the internal cavity,
• wherein the component includes an external surface to be coated, an internal cavity including an opening towards an outside of the component, and the plurality of cooling holes extending from the internal cavity to the external surface, and
• wherein water is filled in the plurality of cooling holes with a masking material and the hardening is done by freezing the water to water ice.

A device used in a masking process for masking cooling holes in a turbine component, the device comprising:

• a carrier for mounting the component, the carrier includes an internal flow channel, connected or connectable to a water supply, the internal flow channel includes an exit opening;
• a cover with an internal surface including a plurality of sealing faces;
• a cooling unit for reducing a first temperature of the cover at least in an area of the plurality of sealing faces to a second temperature which is below a melting temperature of water ice;
• and
• a pressure system connected or is connectable to the carrier, the pressure system introduces a pressure pulse into a fluid in the internal flow channel of the carrier,
• wherein the component includes an external surface to be coated, an internal cavity including an opening towards an outside of the component, and the plurality of cooling holes extending from the internal cavity to the external surface, and
• wherein the carrier is adapted to the component such that the exit opening is in a flow communication with the opening of the internal cavity when the component is mounted to the carrier, and
• wherein the cover is adapted to fit to the component such that the plurality of sealing faces are located at the locations where the plurality of cooling holes are present in the external surface and such that the plurality of sealing faces rest tightly against the external surface of the component sealing the plurality of cooling holes against leakage.