Annealing copper pipe, problem

[bawldiggle]

Is it possible to over anneal copper pipe.

Our house is 70 years old and I am replacing all ancient plumbing with copper.
Using non annealed copper pipe in one difficult location with a lot of (cold formed) bends I tried to de-stress the rigid pipe work by annealing and to make final connections under the timber floor a little easier. Under floor space is 18inches high (500cm in our metric system,
I am the human ferret.

One of the in-wall 1/2inch pipes I think I might have over annealed.
- used MAP gas
One annealed section (about 1 foot long) is almost like butter.

Q1: With the annealed section, is there a risk of fatigue and cracking in the long term ?
- the partly (sectioned) annealed pipe is ...

1. about 4 feet long after a 90° capillary elbow.
2. the last pipe run to the tap outlet (fawcet?) -- mixer bridge/breech (as we call them here)

The pipe is for hot water (max 60° C) so I assume there will be a little movement over time as the hot water heats and cools the pipe.

I have been DIY plumbing for many decades but this was my first experience of annealing.
Judging the color during heating was very difficult to judge -- it turned a silver color but was not cherry red.

I would be very grateful for any input, as she-who-must-be-obeyed wants it finished NOW!

Thank you

 

[frodo]

yes you can heat to much and burn it up. anealing is heating the pipe not getting it red hot and melting

the easiest and best way is to use a pipe bender and your torch.

after it is bent, cool it with water


why dont you buy some soft copper instead of trying to use hard drawn ?http://screencast.com/t/TpMkkcAfoc

 

[Mr_David]

As Frodo suggested Soft rolled copper is already annealed.
It is allowed to cool slowly giving it's soft bendable qualities. If you quench it with water while it is hot it will harden.
If you are using type "M" hard copper , it may weaken the thin tube if you bend it.
I have heated hard tube to make an offset but it is not recommended.
As you bend it, the tube stretches a little on the outside radius and compresses on the inside radius of the bend.

 

[bawldiggle]

Thank you Frodo and Mr_David,

Buying soft copper pipe has made my project considerably easier.
- and having used the soft copper has proved to me that my annealing hard copper had created butter. I definitely over annealed.
- I also bought decent quality pipe benders, budget models were crushing, wrinkling and distorting the end result.
- I sacrificed about 2 metres (6ft) of soft copper to play with and get the feel of its behaviour.

It proved to be easier and less time consuming to buy a roll of soft copper rather than try to anneal sections of hard copper

Thank you for your support