general joints plumbing

[pintail120]

Help, please help,
how do you make a decent joint when joining two copper pipes with brass compression joints using olives
I have old 3/4 copper but the chap at the merchant gave me special big/fatter olives to use with the brass compression joint as it needs to join plastic on the other side.
Everything leaks, drip drip, drip
the plumbing shop says, hand tight and then just nip it. The plumbers that were putting in my megaflow disagree and tighten these joints with some serious effort and they say you must use a paste stuff on the olives, does this pasty stuff really help?
cheers
Gavin

 

[AND1234]

I'll try to help you out...
You say its old 3/4" pipe. Was the section to be jointed sound, and free from scratches/burs. A scratch along the length of a pipe will cause a leak path. Presumably you've already tried tightening an olive on in which case can you afford to cut back to a more sound section of the pipe?
Compression fittings will need more force than just a nip, but not much more. Often until you get more experience its better to not over tighten and then apply a bit more if it still leaks...

Not sure about using paste but I have used PTFE tape wrapped around an olive when leaks become problematic.

You do not say if leak is from copper of plastic side of this compression joint or both but hope some of this may help?

 

[Rob]

If your connecting to proper 3/4 copper then you buy 3/4 olives.

To connect the other side to plastic make sure your using correct insert iside the plastic. From experience even copper olives are ok, never needed anything special.

 

[Slugbabydotcom]

First you say

two copper pipes

Then

it needs to join plastic on the other side.

Are we talking a joint between plastic and copper or as you stated 2 copper pipes?

Theres a bit of a knack to how tight you turn the nut. I remember it took me quite a while to get it 'spot on' when I was an apprentice.
For a DIYer in this situation I suggest to try it just nipped up first and then take it a little past where it stops leaking. Max force just causes disasters.

Many moons ago there was some recommendation by the manufacturers on how much they should be tightened. I wonder if this could still be found on their website?

PTFE tape is a good substitute for pasty stuff ...... Jointing paste. but it must be wrapped in the same direction as the nut is turned. Remember its the olive that makes the joint , not the thread. So wrap the tape primarily around the olive with no more than a turn or two around the thread.


PS found some instructions for you HERE

 

[pintail120]

Are we talking a joint between plastic and copper or as you stated 2 copper pipes?

apologies for being so unclear
basically I have multiple leaks..............
anyone need extra water?

I have stop cock connected to 3/4. This device I assume is metric cause the plumbing merchant gave me special olives to take up the extra space. The joint between this stop cock and 3/4 leaks.

Additionally to that I have a join with a coupler, one side plastic the other side 3/4 copper. The copper and plastic side leaks.

I have a T compression joint and on the 22mm plastic side it leaks and on the 15mm copper side it leaks.

I have noticed that the pipe does not seem to align very well into the hole of the compressoin joint when it is 3/4 copper. I think the compression joint was made to accomodate 22mm and the special olive takes up the slack, but this allows the pipe to be misaligned and then the olive becomes misaligned too. Once this happens nothing can move that olive to get it straight.

My bathroom is requiring a large move around and all the extra piping and joints I have used push fit and this stuff is amazing, but concerned about life expectancy. All the interfacing between the plastic is the leaky issue.

I had the plumber over to fit the pressurised cylinder and I was doing all the rest of the work. He has been plumbing for 30 years and he did maybe 35 joints in 3 hours and used the paste and NOTHING LEAKS!
When may I pull my hair out? NOW and then agian later or just both?

Was thinking of taking up plumbing as a career as I was enjoying building all the bits but after turning the water on this just makes me want to blow chunks!

thanks for all the advice so far guys much appreciatted

 

[Slugbabydotcom]

All the interfacing between the plastic is the leaky issue.

So I guess you never used inserts on the plastic then?

Any pipes under stress will always be harder to seal

I think the compression joint was made to accomodate 22mm and the special olive takes up the slack,

Yes thats right

but this allows the pipe to be misaligned and then the olive becomes misaligned too.

Are you sure that they are indeed 3/4" conversion rings you have there and not just 22mm. There's less than a millimetre in it but you can see or at least feel the difference in size between 3/4 and 22 when you put 2 rings together.
Obviously a 3/4" pipe may not sit as square in the fitting as it is slightly smaller

 

[doitall]

What makes you think plumbing is easy

 

[ChrisR]

You are putting olives onto the plastic pipe?
Speedfit recommend copper olives, only. Cuprofit (Conex) I remember say finger-tight then one turn, which feels like a heck of a lot for copper, but not much on plastic.

 

[pintail120]

So I guess you never used inserts on the plastic then?

every piece of plastic has an insert in it. oddly only where the plastic has an olive does it leak(mating up copper)

Any pipes under stress will always be harder to seal

what do you mean by stress? are you refering to the water pressure?

Are you sure that they are indeed 3/4" conversion rings you have there and not just 22mm. There's less than a millimetre in it but you can see or at least feel the difference in size between 3/4 and 22 when you put 2 rings together.

yes they are definitly the 3/4 ones as they are fatter, when I ran out I thought I would go to BQ and get some more(originally I purchased these at the plumbing merchant). BQ had some 3/4 but they were slim like the 22mm, so I assume they are for proper 3/4 compression joints so left them. Went back to the merchant and got them there just to be safe.

When I refer to them as slim or fat I am not refering to the ID or OD

Obviously a 3/4" pipe may not sit as square in the fitting as it is slightly smaller

so I think if the pipe is not tightened when it is straight then the olive will not be square with the compression joint. Olive not square then it will leak.

Going to the merchant this morning and going to buy a whole lot of olives re do all the joints with Boss jointing compound. The plumber that was at my place puts down zero leaks to that stuff.

 

[pintail120]

I would almost regard this as a trade secret,
This should seriously be made a sticky:
USE BOSS sticky guey paste,
NO MORE LEAKS - peace has been restored to the palace

 

[Rob]

I would almost regard this as a trade secret,
This should seriously be made a sticky:
guey paste

I dont know what that means, but no paste is the difference between lots of dripping and completly dry. OP has lack of basic plumbing skills.

 

[pintail120]

guey paste

called Jet-Lube V2 plus

I dont know what that means, but no paste is the difference between lots of dripping and completly dry.

never said lots of dripping, just said ALL the joints were leaking, maybe one drip per 10min - now they are all bone dry

OP has lack of basic plumbing skills

what does OP mean?

considering I have now achieved what I set out to do and made some major changes so far I do have some skills. maybe better put lacking a finer detail.

I dont know how this paste totally seals a joint, it never goes hard as glue does. Plumbers all use it so it definitly has a purpose, anyone care to explain how this paste does not get washed away and the leaks re-appearing?

 

[Rob]

Everything leaks, drip drip, drip

never said lots of dripping, just said ALL the joints were leaking

I would almost regard this as a trade secret,
This should seriously be made a sticky

The plumbers that were putting in my megaflow say you must use a paste stuff on the olives, does this pasty stuff really help?

Not such a secret after all then.