View Full Version : question on Oakum

10-04-2005, 02:18 PM
Can someone explain what oakum is and how it is used? Seems like it is used to solder a lead joint?? Is this correct??

I have a second floor bathroom in which I can see the toilet connections from below as the ceiling of the 1st floor bathroom is exposed.

Seems like there is a lead pipe running horizontal for about 8 or 9 inches right below 2nd floor toilet which then connects to cast iron vertical pipe that drains out to the street.

While this connection is very sound w/ no signs of corrosion or leaks is it wise to leave it be or replace while I have the ceiling exposed?? ANd lastly is that oakum that is sealing the lead joint to the cast iron??

thanks in advance,

10-04-2005, 02:41 PM
Oakum is used with lead, not solder. If you used solder in the joint you would crack the cast iron fitting when you attempted to caulk the lead tight. The oakum seals the joint, and the lead seals the oakum and keeps it in place. I would remove the lead bend and replace it with cast iron, but others would go with PVC or ABS.

10-04-2005, 03:53 PM
hj is right, I would also use cast iron.
I have seen lead risers, but they were used in the early part of the last century in my neck of the woods. But in all my travels, I have seen very few lead bends.
I've gotta believe that the brass cl. flange isn't sealed to the lead pipe well anymore.

10-09-2005, 03:38 PM
Forgive my ignorance, but when I worked in the log home building field, Oakum was a rope insulation we marketed. It was available in either oiled or dry, whichever the builder preferred. It was useful in repelling insects and in creating an "old" look to log homes.

10-09-2005, 04:41 PM
I think it is the same stuff...you stuff the joint with it and then seal it in with liquid lead poured with a ladel. I remember seeing my father do this (I've never done it).

Gary Swart
10-09-2005, 04:48 PM
I'm pretty sure Jim is correct. Oakum is a caulking material that is tightly packed into cast iron joints then topped with molten lead. It's not really a DIY job. When ship planks were caulked, I think something like pitch or tar was probably used to top it off, but certainly not molten lead.

10-10-2005, 08:35 AM
Plumbers use oakum and it's jute or hemp that contains oil. I used to think that it smelled of tar, but it may have just been oil.
And when its packed tight and it gets wet, it swells.