Underground conduit cleaning

[gabany]

Does anyone know of a method, or preferably have experience, for cleaning partially blocked RMC - underground and concrete encased?
More specifically several feeds (3/4" & 1") in a duct bank that have not fared so well after years of water, dirt, ash, and acid infiltration.
Cleaning / Rodding / Roto-Rootering an existing conduit (a concrete encased conduit), ultimately allowing the new installation of a properly rated cable. Can it be done?

 

[brian john]

We have used a plumbers camera to investigate the issues, and the pulled different sized mandrels through the conduit, sometimes it works sometimes not, Having the camera on a Snake was a big help.

 

[don_resqcapt19]

I have hooked a fire hose to underground ducts to flush them out, but you still need to use a mandrel after you have flushed them to verify that there is not a soild obstruction or a colapased section.
Don

 

[mdshunk]

I got a flyer a while back from a company that makes wire brush mandrels. That sounded like a fine way to get little sharp metal bits all through the pipe. Didn't appeal to me.

 

[cadpoint]

Time is againest You

Time is againest You

Other than the fact that time and other chemicals are againest You,
Coke-Cola for short terms situations, seen it clear out dirt cludes,
desolve rocks, grout, works great for 1/2" - 3/4", never use more than
a few liters and left it over night.

 

[growler]

Coke-Cola for short terms situations, seen it clear out dirt cludes,
desolve rocks, grout, works great for 1/2" - 3/4", never use more than
a few liters and left it over night.

I have herd of useing coke. We did use white vinegar on a short run of 1". Something like CLR might work but you would need to flush the pipe well.

 

[Jeff Weissman Electric]

Diet coke & Mentos works every time.
Hey! You set me up...OK?

 

[gabany]

Thanks for the replies. I never thought of coke, but i heard it works wonders cleaning toilets.
I talked to mobile pressure washing company, they have a 1/4" high pressure snake, with compressed air or fluid, as another option.

 

[augie47]

blockages

blockages

I've seen the white vinegar work well on grout.

 

[Terrynistler]

I carry a shop vac with leaf blower as well. Works on most also easy for getting your string lines through and blowing water out.