The cleanout cap on a 3" PVC sewer pipe is too tight to remove, it was tightned with a sealer many years ago. No glue was used. Are there any chemicals that can dissolve the sealer and penetrate to loosen the cap. Liquid wrench did not help.
Thanks, N.

When that happens to me I use one of two ways to remove the cover.
1) I take a hammer and chisel and attempt to start it by seeing if I can jar it loose by tapping it counterclockwise to start it to unscrew.
2) If that fails I take the hammer and beat the cover out of there and replace it.
Good luck, Tom