What kind of glue did you use to glue the caps on?
PVC requires a special type of glue:
http://www.google.com/search?comple...fai=CCG3gaT4WTPSnH4TIhgTXnPTUCgAAAKoEBU_QM7BI
PVC requires a special type of glue:
http://www.google.com/search?comple...fai=CCG3gaT4WTPSnH4TIhgTXnPTUCgAAAKoEBU_QM7BI