View Full Version : What torch do I need?

06-15-2010, 11:03 AM
I've decided to replace a short section of pipe that is quite corroded inside and/or has lots of deposits on the walls. (This was my previous "leprosy" post.) Anyway, what sort of torch do I need in order to loosen up the old oakum and lead joint that connects this pipe to a very heavy-duty Wye (right before it exits building)? Also, please give your tips for how best to do it.

I'm not clear if there are different torches for copper vs. cast iron joints... different temperatures... different flame shapes, etc? Please advise.


06-15-2010, 11:44 AM
You are better off drilling the lead and using a screw driver to pry the old lead out.
Just because you heat the pipe up, it doesn't always mean that the lead will be smart enough to fall out of the joint.
It takes a big torch to heat up a 4" cast iron pipe.
I don't even try.

06-15-2010, 12:27 PM
Big as in a #7 rosebud tip which takes a lot of gas to feed such as a professional welding

shop may have !

Do what terry says and drill it out !

By the way when using a big torch you have to be aware of methane gas coming up the

sewer pipe !

06-15-2010, 02:24 PM
An oxy-acetylene cutting torch so you can use the oxygen lance to blow the melted lead out of the joint. Otherwise the torch will just melt the lead and then it will harden just like it was.

Wally Hays
06-15-2010, 06:05 PM
There is a tool called a lead pick but finding one is near impossible. Mephisto tool might have one

06-15-2010, 07:37 PM
You also run a chance of cracking the cast iron with a torch

06-15-2010, 08:31 PM
Thanks everyone for all your advice--especially the bit about not blowing myself up, would not have thought of that! I ended up drilling it out as per Terry's suggestion. It worked all right but took a while and killed two bits.

Now I need to find a Fernco or other donut-style fitting to mate the old and new CI pipes.

06-16-2010, 06:41 AM
NEVER cracked a cast iron hub with a blowtorch OR a cutting torch.

steelers fan
06-16-2010, 05:05 PM
I have actualy pulled them with a #2 on a mc tank