C) sealing {HEAD ~ the hole} by connecting one end of a tube of {TAIL ~ a predetermined length} to the outside of the burr, compressing the protruding end of the tube, and then welding the compressed part of the tube 
C ) sealing { HEAD ~ the hole } by connecting one end of a tube of { TAIL ~ a predetermined length } to the outside of the burr , compressing the protruding end of the tube , and then welding the compressed part of the tube
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH