I have an underground rubber hose with an one inch crack in it. I am hoping I could just seal it, but I don't know what to use and I don't want to make it worse.
Is it worth trying to seal it or are these kind of cracks unfix-able?
I was thinking of using contact cement to close it and maybe reinforce it with this waterproof epoxy putty I found.
Since you already have to dig it up to fix it, don't bother trying to repair the crack. Cut out and replace the damaged section of pipe. Use a coupling suitable for the type of pipe you are working with and that is rated for burial.
Best choice for a long term fix is to replace the section.
If replacement is simply not an option, then consider using self-sealing silicone tape. You'll want to depressurize the line first, and make sure you have room to move the tape around while you patch it up. Most manufacturers state the tape is only for short term repair, but there is quite a bit of anecdotal evidence that it will last for years.
Keys to remember with tape are to keep it stretched when applying it; try to keep the tape surface clean between layers; and make sure you overlap according to the instructions. You'll want to loop 3 - 5 times over the area and extend past the break by an inch on either side.
