Clogged 3/4" Gray PVC conduit

[Craig Clayton]

Pour Hydrochloric acid down the conduit at a 50% that will eat out the cement. when it is clean flush with lots of water. There is sometimes a cause why cement falls down a sealed conduit 1 minor accident or 2 somebody was upset about ?.
Craig Clayton

 

[blackie65]

cut a long piece of fish tape and stick it in a drill. Work it from both ends...this sometimes helps break things up.

 

[socallly]

Craig,

Will the acid eat the pvc also?

 

[BillBeyer]

Just curious as to what type of 90 did you install in the base of column? Long sweep 90 or standard 90?

 

[Craig Clayton]

I use to work in construction as a electrician and have had conduit filled by causes unknown. The 50 % hydrochloric acid is strong and maybe be difficult to get unless it comes from a chemical supply company. Battery acid H2SO4 sulphuric acid is similiar and will eat the lime out in the cement. It will produce Carbon Dioxide gas and water the Baking Soda at any time can be poured on to neutralize the reaction. Wash with water and wear a full face shield. The PVC will stand 50% HYDRO acid but do not leave it on for ever. All our chemical lines in the plant are PVC and they handle strong acids for years.
Craig Clayton

 

[socallly]

Bill,

Standard sweeping 90º, see picture

 

[socallly]

Ok with all the suggestion I've gathered here, my plan of attack for this weekend will include the following.

1) Attach length of fish tape to drill.
2) locate, purchase and pure acid.
3) if all fails try to core drill a 2 or 3" Dia hole in footer to get to the conduit.

I would try the sand blast method, if I owned one.

Thank you,

 

[hr3]

I use to work in construction as a electrician and have had conduit filled by causes unknown. The 50 % hydrochloric acid is strong and maybe be difficult to get unless it comes from a chemical supply company. Battery acid H2SO4 sulphuric acid is similiar and will eat the lime out in the cement. It will produce Carbon Dioxide gas and water the Baking Soda at any time can be poured on to neutralize the reaction. Wash with water and wear a full face shield. The PVC will stand 50% HYDRO acid but do not leave it on for ever. All our chemical lines in the plant are PVC and they handle strong acids for years.
Craig Clayton

Yeppers this works every time,, I too have had to do it in the past.. The last time we it happened it took 2 days to eat it's way through..

 

[DiskDoctr]

Yeppers this works every time,, I too have had to do it in the past.. The last time we it happened it took 2 days to eat it's way through..

+1 for HCL. Look for Muriatic Acid. The fumes are bad and will burn your nose, throat, etc, so don't breath it.

It will make the cement in the concrete brittle.

Good luck.

 

[Craig Clayton]

To DiskDoctr
As I understand the problem the cement plug is inside the conduit and we want to make the cement brittle in the conduit. Then flush with lots of water.

Craig Clayton