Help with 2" Cast Iron Hub

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by victorhall, Jul 19, 2011.

  1. victorhall

    victorhall New Member

    Messages:
    6
    Location:
    Maryland
    Hello all,
    I've been a huge fan of this forum, and have found many good answers on this site before thanks to the search engine. This time, however, I ran into a snag that's got me stumped, and greatly appreciate your sage advice!

    I've got a 2" cast iron hub sticking out of the ground. Above the hub was a galvanized steel system joined with lead and oakum. The steel was at the end of its life, and I am looking to replace with PVC. The joint is out, but none of the Fernco donuts fit: I tried the SV size from the big box store, and special ordered the XH size (P/N 22UX-205). But it's still too small. The ID of the hub is about 3 1/4", which according to the rep at Fernco is in-between sizes, making a donut not an option.

    I think the most painless solution is to buy a short section of cast iron, and remake a lead/oakum joint, then attach with a rubber coupling to PVC. But I have some unknowns:

    1. Does the cast iron look to be in good enough shape for this?

    2. Is the lead/oakum something an ambitious DIY'er can do? I can weld and solder, and am not afraid to do a little research and get my hands dirty.

    Thanks in advance!
    -Vic

    SAM_1269.jpg SAM_1270.jpg SAM_1278.jpg SAM_1272.jpg View attachment 13550 SAM_1273.jpg
  2. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,309
    Location:
    Maine
    Did you try the rubber insert with a piece of PVC stuck into it, because the pipe expands the rubber. If so and it's still too loose you can get a caulking ferrule from any plumbing supply house.
  3. victorhall

    victorhall New Member

    Messages:
    6
    Location:
    Maryland
    Hi Tom,
    Thanks for the reply! I did try the rubber insert with the PVC already sleeved, and it was still fairly loose. What's the scoop on caulking ferrules? Do they provide a leak-tight seal? I wonder if they're allowed by Code (I'm under the International Plumber's Code in my area.)
    -Vic
  4. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,309
    Location:
    Maine
    They are legal and arguably the best way to transition to PVC
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,247
    Location:
    Cave Creek, Arizona
    A piece of 2" pipe, (cast iron or steel), with a lead/oakum joint is MORE than adequate for your purpose.
  6. KULTULZ

    KULTULZ Jack of all trades, Master of none

    Messages:
    85
    Location:
    ROCKVILLE, MD
    Can someone explain how to use a caulking ferrule? I am going to have the same problem with a neighbor's house and would like to know how to replace existing galvanized to 2" hub properly with CI NH.

    I hate to hijack a thread but I think this info should be contained within this thread for future search.

    THANX GUYS!

    Attached Files:

  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,247
    Location:
    Cave Creek, Arizona
    Inserting ANYTHING into a cast iron hub is done the same way. You place it in position, pack oakum around it leaving about a 1" space above it, melt the proper amount of lead, pour it into the joint, then hammer the lead tight with inside and outside calking irons. Most "ferrules" are threaded which is not always the best way to transition to plastic.
  8. KULTULZ

    KULTULZ Jack of all trades, Master of none

    Messages:
    85
    Location:
    ROCKVILLE, MD
    HJ,

    I will remove the present galvanized pipe (pressed into cast iron hub in floor) and replace with hubless cast iron into the hub. The neoprene gaskets are not up to the job?

    How does one use the ferrules? Are they necessary for hub/spigot to hubless?
  9. victorhall

    victorhall New Member

    Messages:
    6
    Location:
    Maryland
    Thanks all for the replies. I'm leaning heavily towards the cast iron stub, with a lead/oakum joint. Just gotta find a supply store locally that'll cut me off a few inches of 2" cast iron...or I'll just have 9'8" of "extra" pipe laying around :)

    I've read that you can lead directly onto PVC, but I imagine that there's more skill to that, since you have to keep the temperature of the lead low enough to not melt the PVC. Looks like PVC's melting point has a pretty wide range, and lead's is within that range.

    I'll try to get pics of the solution when it's all said and done.
    -Vic
  10. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,247
    Location:
    Cave Creek, Arizona
    quote; Looks like PVC's melting point has a pretty wide range, and lead's is within that range.

    Maybe so, but hot water will "soften" PVC very rapidly and molten lead is a LOT hotter than that. Cast iron joints cast before the advent of rubber "donuts" did not necessarily have to conform to any rigid standards, (in fact before "spin casting" it did not even have to be concentric), which means a rubber donut may, or may not, fit it perfectly, plus you have to clean the interior of the hub very thoroughly to give it a smooth surface to seal to.
  11. cwhyu2

    cwhyu2 Consultant

    Messages:
    1,348
    Location:
    Cincinnati OH
    You can also use lead wool,it compact the same as a poured joint.
    But it may be hard to find.
    The last time bought it was 1999.

    Google lead wool having a problem with links.

    Attached Files:

    Last edited: Jul 20, 2011
  12. nukeman

    nukeman Nuclear Engineer

    Messages:
    711
    Location:
    VA
    If you need a little bit of CI, let me know. I have some 2", some 4", and a few fittings. It is used, but solid. I could send you a piece. I'm in central VA, so it would get to MD in no time.
  13. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,309
    Location:
    Maine
    Lead wool is not legal. To caulk PVC to c.i. you can avoid melting the ferrule by stuffing a wet rag into it when you make the pour. Some scorching will occur and you need to be well ventilated and do not breath those plastic fumes. Other than that the procedure is the same. Be sure the lead and plastic has cooled before you set the lead.
  14. plumber2011

    plumber2011 Expert Plumber

    Messages:
    70
    Location:
    Boston, Massachusetts
    If you go PVC install a PVC manhoff fitting (only found at a local plumbing supply store or online) into the hub first and then use oakum and lead or oakum and a LEAD SUBSTITUTE to seal the fitting into the cast hub...see images. Here, the PVC manhoff fitting is very thick and easily withstands the molten lead pour.

    You may also want to check with your local plumbing supply store and see if they have both the service weight type and extra heavy type donuts....betting the extra heavy (XH) donut will fit this hub...;)

    Questions? Let me know, OK?

    Attached Files:

    Last edited: Jul 23, 2011
  15. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,309
    Location:
    Maine
    You can't use the lead substitute around here if an inspector looks at it.
  16. victorhall

    victorhall New Member

    Messages:
    6
    Location:
    Maryland
    Pay it forward

    WOOHOO! Poured my first lead and oakum joint. No fuss, it appears to be leadk-tight, and I'm feeling a nice sense of accomplishment. You pros, feel free to criticize the work! If I did it wrong, I'd like to know. And hopefully someone can learn from any mistakes I may have made in the future.
    A HUGE thanks to nukeman for helping me out with a short piece of cast iron to use. I owe you one!!!

    Bought a 5 lbs lead cake from my local specialty plumbing store, along with some oakum.

    I packed the oakum down, and tamped it with a hammer and home-made yarning tools made with short sections of PVC - this allowed me to make proper angles to pack the stuff down. Consequently, I used a screwdriver, and more pieces of custom-cut PVC to caulk the joint once it was poured.

    I used MAPP gas, and an old pot to melt the lead - had the fire extinguisher nearby, and was careful about not burning the house down.

    Here are some pics:
    IMG_2151.jpg IMG_2157.jpg IMG_2159.jpg IMG_2162.jpg IMG_2165.jpg
  17. victorhall

    victorhall New Member

    Messages:
    6
    Location:
    Maryland
  18. cwhyu2

    cwhyu2 Consultant

    Messages:
    1,348
    Location:
    Cincinnati OH
    Looks good to me.I am old school taught I was trained to do pours on horizontal joints and also to do a wiped lead joint. Now that is a fun thing to do.
  19. nukeman

    nukeman Nuclear Engineer

    Messages:
    711
    Location:
    VA
    Awesome. :) Glad it worked out for you.
  20. KULTULZ

    KULTULZ Jack of all trades, Master of none

    Messages:
    85
    Location:
    ROCKVILLE, MD
    Congratulations!

    Very impressive and informative.
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