Pipe dope or weld?

[e-tek]

If you want to see how serious "metal fume fever" can be, read the following:

SAFETY - III : A Case study
Death by Metal Fume Fever

Posthumous Demonstration by Jim Paw-Paw Wilson
http://www.pawpawsforge.com
May 13, 2005

I have been known to be wrong (ask Mrs E-tek!!) and I'm not saying anyone should just believe me, but let's look at the best info possible for all these matters.
FOREMOST, let's NOT confuse things especially the EVIDENCE!
While I agree "Metal Fume Fever" can be dangerous, it can also be caused by a variety of metals being burned. Some metals can be fatal, some (like Zinc) usually not.
The link you reported is a layman's "post-mortem" on a very sad tragedy with MANY confounding confusing and likely poorly-reported factors. Firstly, the guy had emphysema, which obviously contributed. Second, looks like there where several - or MANY - metals burning in there, including Zinc Oxide. Zinc Chloride, an "ITC coating in the kiln was burned off"..... Thirdly, sounds like he stayed when others left, making one wonder what the O2 levels where....

Of course all of us should try not to **** up any fumes!! But I also like to look at the facts of matters.

 

[Steevo]

...I always drank lots of milk when burning a lot of galvanized pipe, it tend to counteract the effects.

Now there is a scientific remedy if I've ever heard one.

 

[Flying Low]

You said your pipe was not made in the USA. I have had a big problem welding some pipe marked "made in India". Even with premium pipe It should be plenty strong to thread it. That is how it was designed.
Good luck,
David

 

[e-tek]

Originally Posted by SK Guy View Post
...I always drank lots of milk when burning a lot of galvanized pipe, it tend to counteract the effects.

Now there is a scientific remedy if I've ever heard one.

Milk, while not truly a "universal antidote" (see below), has an important place in the treatment of certain types of poisoning. It coats the stomach, oesophagus and throat, reduces acidic conditions, reacts with poisons that react with proteins and binds with many toxins.

*A true "Universal antidote" consists of 1 part of magnesium oxide, 1 part of tannic acid and 2 parts of activated charcoal. The magnesium oxide neutralizes acids without formation of gas; tannic acid reacts with many substances to form insoluble salts (alkaloids, metals); activated charcoal adsorbs dyes, toxins, alkaloids and some salts of metals.

 

[gmwelder86]

dope tape than dope it will never leak atlong as the threads are decent and your not a panzy when making up the fittings. Never use just one either tape or dope. Never of them are designed to "seal" the pipe to the fitting. They are made to lubercate the joint as it makes up to form a mechanical joint in the required depth of the tapered thread of the pipe.

Also welding 1 1/2" pipe is a biotch and a half unless you socket welding it and than your looking at a ton of money in the fittings alone, much less your time and with the galvi the risk to your health.

 

[A29]

I use Permatex #2.

 

[PAToyota]

FOREMOST, let's NOT confuse things especially the EVIDENCE!
While I agree "Metal Fume Fever" can be dangerous, it can also be caused by a variety of metals being burned. Some metals can be fatal, some (like Zinc) usually not.

Of course all of us should try not to **** up any fumes!! But I also like to look at the facts of matters.

I agree that there were a number of things going on there - and a few of them were certainly extreme. As such, best to err on the side of caution. Without knowing exactly what someone is welding on, where they may be welding, and what other conditions they may have it would be best to stay away from welding on galvanized.

 

[kbkna]

I think we could debate whether welding is safe or not I WILL NOT BE welding it together. I have used the tape/dope together method and time will tell if it works. I will keep you all posted.

 

[Heavy Metal Doctor]

Are we talking about threaded pipe ??? If so, then teflon tape or liquid pipe sealant is fine --anything more is excess work. I use mostly the liquid stuff (to avoid peices of tape tearing off and clogging something up) for lots higher pressure than air lines ever see.
If you use tape - remember to wrap it clockwise as you look at the end of the male thread - that keeps the tail end from "rolling up" when you start the threads.
Liquid stuff is great - but eveything must be clean.

 

[A_Pmech]

On the subject of pipe dope and teflon tape...

If you study (ANSI/ASME B1.20.1) you'll discover that American National Standard pipe threads, even when made up to the standard will leak without the application of a sealant. This is because the crest the thread is truncated more than the root. Thus, a spiral leak path is present in ALL pipe makeups using the American National Standard thread without sealant.

To cover this issue, American National Standard Dryseal Pipe Threads (ANSI/ASME B1.20.3) were created. The standard is based on the B1.20.1 standard, but differs in the fact that the roots of both threads are truncated more than the crests. As a result, the crest of the threads will engage the root of the mating thread and plastic deformation will occur at this point, sealing off the spiral leak path.

 

[cowboy73]

I have used this stuff on threaded steel pipe:
View media item 7104
Made by Hercules Chemical Company. It's sticky as hell and does a great job sealing up the threads. It takes alcohol or gasoline to get it off your hands and tools!