Really basic questions that are bugging me - bring on the ridicule!

[Masood]

OK, ladies and gents, I know the correct answer to all of these is "You should have done an apprenticeship", so feel free to pile on the mickeytaking (as long as you also answer the questions!)

1) Paste - Boss White/Hawk White etc is described as thread sealant. I was always taught to put it around the olive and the end of the pipe like you would with PTFE tape, so it forms a seal as it enters the fitting. Is this wrong? Should it go on the thread?

2) On the subject of paste, what's the best one for potable water? Boss Green is pants.

3) Do you ALWAYS use paste? Or on new pipes and fittings is the olive enough?

4) When would you use PTFE tape over a paste?

5) Is there any major difference between brass and copper olives (apart from the obvious!)? When to use which?

That's it for now. Please be kind! :grin:

 

[Keefy]

Someone's hacked Masood's account!! Alert the moderators!!

 

[mfgs]

1) you are using the paste in the right place for compression joints. On screwed joints you can use boss white on the thread with hemp etc or some people use just boss white on theaded gas joints.

2) I use fernox water hawk, does the job ok. Although no potable water pastes feel as good as boss white.

3) I am starting to use paste on all compression joints now, I never used to but I don't see how it can be a bad thing to put paste on every joint as surely there is then less chance of a leak.

4) If its an old joint and the olive has been a bit crushed a bit of one wrap ptfe around the olive is better than any paste. Obviously in an ideal world the olive and nut would be replaced but its not always possible.

5) I prefer copper olives as they are softer so you don't need to tighten the nut up as much. It is however easier to damage a copper olive by over tightening the nut.

 

[GasmanxxxR1]

i like jet blue plus from plumbcentre, pts do their own version. I hate the fernox stuff in the little blue tubs, sticks to everything but the joint your trying to make

 

[kay-jay]

Jet blue plus is universal and can be used on gas and potable.

Thread sealant refers to mild steel and the like. On compression around the olive is fine.
Ptfe when remaking an existing connection.

 

[kay-jay]

Oh and olives should be brass on heating as there is less thermal expansion than copper so is less likely to start weeping

 

[Masood]

Thank you all for your comprehensive replies and for not taking the mickey! I'm the kind of person who likes to understand why things are done a certain way so I can keep improving. Thanks again!

 

[TBServices]

Another vote for jet blue here

 

[vern]

Another vote for jet blue here

And another I use it on my sarnies now instead of butter love the stuff :vampire:

 

[gassafe]

Sorry to hijack a thread, but when using loctite 55 cord am I supposed to then add a smear of jet blue, or is this not needed with loctite cord!? I have always added some joint compound to the thread on top...

 

[Mike Jackson]

Shouldn't need it ideally but I always used to add a smear. Tend to use Loctite 577 now though.

 

[gassafe]

Shouldn't need it ideally but I always used to add a smear. Tend to use Loctite 577 now though.

Just googled it... Wow it's pricey stuff!!!! Not sure i can justify 18 quid for a tiny bottle!

 

[peteheat]

1) Back in the "old days" we were taught to use Boss White on the threads not the olive as it lubricated the threads and made it very handy to start threading the nuts.

2) Usually use Fernox on potable but no problem with Boss White either.

3) Paste won't do any harm on your compression joints, see first answer.

4) On the old olive I am inclined to use gas grade PTFE simply because it has more body.

5) Brass for the majority of standard joints, copper olives on soft copper pipe to prevent crushing.

 

[neily01]

Jet blue all day on olives rocol gas seal where req and quite liking my loo title 55 now.

 

[neily01]

Now looking at that loctite 577 quite handy for htg and hc manifolds. Saw them last year at phex they said that when you apply to two metal threads close the joint to eliminate the air instantly will hold to 6 bar after 24hrs will hold up to 120 bar! We had to break a joint one time it took two of us a vice and a scaffold pole works well!

 

[on31ll]

Never used the loctite atuff ! I have some in my possesion that "made" its way into my box onsite ! Mist be good all the has lads and pipefitters use it !

 

[helpsy]

I thought I'd read somewhere that you can't use hemp on pipes with water

 

[Mike Jackson]

You can't use hemp on wholesome water because it can promote bacterial growth.

 

[kay-jay]

I used hemp once....


It gave me the munchies

 

[hammers4spanner]

i thought boss white was not for potable water ?

Sure it says that on the tin

but copper olives for me

loctite 55

jet blue or gas paste

and a nice bcon sarnie withy fried toms and brown sauce please

 

[on31ll]

Oh and olives should be brass on heating as there is less thermal expansion than copper so is less likely to start weeping

Using that rule shouldnt they be brass on hot water pipework too ?

 

[kay-jay]

Using that rule shouldnt they be brass on hot water pipework too ?

anything hot really but domestic hw should be lower temps than heating