Pipe Dope

bowman

has been 20 years since did any major work on my system and now am;
looking for advice on pipe dope for black iron and cast fittings on low pressure one-pipe steam system - Rectorseal #5 (Yellow) or Megaloc with Kevlar (Blue)?
Which do you prefer (or other) and why.
Thank you

EBEBRATT-Ed

The fittings don't care. You will get 100 different answers from 100 different people.

I like regular teflon tape (not blue monster) with Rectorseal True Blue dope.

Why? because that's what I like, and I didn't have leak issues.

But that's just me. Either one of the above will work if you already have some.


Everyone has there own ideas.

mattmia2

What i like about blue moster the most is that it comes on a roll with about a hundred feet instead of one of those little rolls that is like a yard per spool.

jesmed1

Are there applications where it's better to use setting-type sealant vs. non-setting type? I'm not a pro but have used Rectorseal T Plus 2 non-setting sealant on water heater anode rods, and it works well for me.

Hercules Real-Tuff looks similar, ie a white paste with PTFE fibers, but it says it's soft-setting as opposed to non-setting.

I just bought some Megaloc to try. That has the Kevlar fibers instead of the PTFE. Also says soft-setting.

Rectorseal Tru-Blu says it's an "adhesive" flexible-setting sealant suitable for high-vibration environments.

mattmia2

setting type is usually used where something won't seal or is damaged. it shouldn't be necessary between 2 sets of threads in good condition

jesmed1

Ok, thanks. A lot of our boiler piping done 25-ish years ago has the blue stuff, not sure whether it's Megaloc or Tru-Blu. By now it has set pretty hard and I can barely dent it with a fingernail.

Mad Dog_2

I use Rectoseal #5  Yellow stuff on all Oil Burner threads.  That's what the Oil guys I learned under swore by.  I used Real-Tuf white Teflon Paste on all Domestic water threads. I mostly use Megaloc now for most things.  Permatex for really bad threads but never in Domestic water.  They all work  Lubricate the threaded joints for greater make up...some actually seal too.  Mad Dog 🐕 

bowman

Okay. Thanks all.
But for the purposes of this very specific and narrowly tailored question - am looking for advice only related to cast and black iron and malleable fittings carrying low pressure residential one-pipe steam. No other materials no other mediums please.
What do you pro pipe fitters use on steam boiler piping?
Thank you

jesmed1

You might find this previous discussion useful, although somewhat dated.

https://forum.heatinghelp.com/discussion/110291/pipe-dope-for-steam-piping

Mad Dog_2

Just told ya......Megaloc...Mad Dog

Intplm.

@bowman If you are akin to Rectorseal. They now make a blue version that I am using for the first time on a new steam boiler replacement. So far so good. No complaints.
I am also enjoying the success of the blue Monster Teflon tape. It's terrific. The only warning is to follow the directions.....three wraps around the threads only. I learned the hard way. I cracked a few fittings because I used a few too many wraps, using it like the white Teflon.
Otherwise, almost all other pipe dopes will be fine.
I'm using it for 2" and 21/2" BCI, Black cast iron fittings specifically. Not to mention everything else.

Mad Dog_2

As aJr Mech, I spilt the same 2" pvc pool fittings 4 times..too much tape & too many turns. The first Steam boiler I did for a Lic  Plumber in South Ozone Park Queens, NYC, 1986,  I had to run to the Plumbing supply several times and keep buying 3" Ward Steam 90s out of my own pocket because I kept overtightening them and splitting them..witj 3 & 4 foot Ridgids. The Boss left me alone for 4 hours and I was done.  He saw the split 90s and laughed his Arse off..5 foot 3 Sicilian man : "You no gotta maka so tight kid...eh???" 
He threw me the $ I laid out like a gentleman and I never spilt them again .  Mad Dog 🐕 

EBEBRATT-Ed

@bowman
Just like I mentioned in my first post. You have 5 different posters with 5 different answers. It doesn't matter.

Everyone has their own opinion.

It's like which brand of coffee do you prefer?

1 brand of coffee does not taste the same to everyone.

Mad Dog_2

They ALL get the job done....Pick one that has a cool 😎 color...Mad Dog 🐕