Patent ID: 7829010

Claim:
A method of dispensing an additive to a metal, comprising: providing a guide-tube assembly having: (a) a durable sleeve having a receiving end and a dispensing end, and having an inner surface defining a through-hole extending from the receiving end to the dispensing end, the durable sleeve being made from a first material; (b) a sloughable sleeve having an end and a channel, the sloughable sleeve residing in the through-hole of the durable sleeve and being secured to the durable sleeve, the sloughable sleeve being made from a second material; (c) an additive guide tube residing in the channel of the sloughable sleeve and being secured to the sloughable sleeve, and both the durable sleeve and the sloughable sleeve are arranged relative to the guide tube so that the dispensing end of the durable sleeve and the end of the sloughable sleeve extend beyond a dispensing end of the guide tube; positioning the durable sleeve proximate to molten metal; providing an additive wire to the molten metal by feeding the additive wire through the sleeves from the receiving end toward the dispensing end, and into the molten metal.