Pipe thread compound? Can't stop a leak!

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by H20Man, Jan 14, 2008.

  1. H20Man

    H20Man New Member

    Messages:
    12
    Location:
    Alabama
    I've never had good success when connecting brass fittings together using pipe thread compound (rectorseal Tplus2 if it matters). I thoroughly coat both the male and female threads, then tighten them down. I still get water leaking (very slowly). What's the trick? Should you only tighten it a little? Or should you tighten it a lot?

    Thanks
  2. TMB9862

    TMB9862 New Member

    Messages:
    206
    What are you tightening? I use pipe dope then a couple wraps of Teflon. You have to tighten it a bit but be careful at the same time since brass will over tighten once you get Teflon on it. My guess is you aren't tightening it enough though since you should be able to do it without tape.
  3. H20Man

    H20Man New Member

    Messages:
    12
    Location:
    Alabama
    In this case, I'm trying to put a copper 3/4" male threaded adapter into one of the "isolator valves" made by webstone for tankless water heaters.
    http://www.webstonevalves.com/isolatorexp.html

    It's a pain because there's no way to tighten it any extra after everthing is assembled because the 3/4" male threaded adapter is of course soldered to a 3/4" copper pipe at that point. So i have to make a cut in the copper pipe, drain the plumbing, redo the threaded joint, sweat the copper back together, then turn the water back on.......... and it still leaks!

    How tight exactly should I tighten this thing? I don't want to overdo, it...... ?
  4. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    Solder the pipe to the adapter first then install the adapter.
  5. 2islandboy

    2islandboy Lighthouse Engineer

    Messages:
    2
    Location:
    NH/Bahamas
    Indian head Gasket Shellac Compound

    Try using "Indian Head Gasket Shellac Compound" made by Permatex. Auto parts stores sell it. Apply to both surfaces lightly and let it get tacky. It resists almost everything, seals gaps, dries hard, but can be removed later. I've been using it for maybe 40 years on the worst jobs. Smells bad, but safe according to MSDS below. Stains your hands, so it must be good.
    MSDS http://hpd.nlm.nih.gov/cgi-bin/household/brands?tbl=brands&id=16005006
    TECH INFO
    http://www.akd-tools.gr/xmsAssets/File/TDS/PERMATEX/20539.pdf
  6. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    I would wrap the threads with plumbers tape then apply teflon paste over it. Been doing it for years without leaks... Works for me!
    Last edited by a moderator: Mar 14, 2014
  7. H20Man

    H20Man New Member

    Messages:
    12
    Location:
    Alabama
    Ok, I'll try that. How tight should it be? Hand tight? Light wrench pressure? Medium wrench pressure?
    Last edited by a moderator: Mar 14, 2014
  8. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    I would say use a wrench with medium/heavy pressure. Now if you can figure what that is...
  9. H20Man

    H20Man New Member

    Messages:
    12
    Location:
    Alabama
    :) Gives me an idea anyway. :)
  10. GrumpyPlumber

    GrumpyPlumber Licensed Grump

    Messages:
    1,404
    Location:
    Licensed Grump
    I'd use plain plumbers tape over dope any day.
    Plain dope isn't enough on potable.
    Last edited by a moderator: Mar 14, 2014
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