Brazing copper

[AjohnwParticipant @ajohnw51620]

In case I ever do make a steam engine this is an area I wonder about. Boilers. Silver solder is usually used and I read that others can't be used due to sulphurous smoke off coal. There are numerous brazing alloys about that contain various mixes of silver, usually a lower % in in these, copper and phosphorous. Other things too at times

I wonder how this fits in with propane fired boilers – no sulphur so why not?

John

–

Edited By John W1 on 21/11/2015 15:57:03

[AjohnwParticipant @ajohnw51620]

[Keith HaleParticipant @keithhale68713]

There is no reason why a propane fired boiler cannot be put together using copper phosphorus alloys (CuP Alloys) that may or may not contain silver.

Gas fired water heaters, central heating boilers are all made using these alloys.

BUT

DO NOT USE THEM ON COAL FIRED APPLICATIONS.

a hot sulphur bearing atmosphere can cut through a copper phosphorus joint like a hot knife through butter!

regards

Keith

[AjohnwParticipant @ajohnw51620]

Thanks Keith. Be interesting to see if there are any other views.

I was surprised just how many alloys are around when I looked. One aspect concerning choice might be max service temperature as this seems to vary. 20 bar, much higher than I would be interested in need water to be at well over 200C and then there is super heating the steam. The info I found seem to be more concerned about the minimum for refrigeration people.

John

–

[Neil WyattModerator @neilwyatt]

Thanks Keith,

I have about a dozen CuP rods, and have never had the courage to use them.

Neil

[Bodgit Fixit and RunParticipant @bodgitfixitandrun]

Are these alloys safe to use with meths or fuel gels etc?

Edited By Bodgit Fixit and Run on 21/11/2015 20:08:11

[AjohnwParticipant @ajohnw51620]

There are a lot of them. So which ones

**LINK**

John

–

[Keith HaleParticipant @keithhale68713]

The most common alloys can be found here

http://www.cupalloys.co.uk/for-refrigeration-engineers/

They are readily available. Generally speaking

increasing silver content improves joint ductility

Increasing phosphorus content improves fluidity and reduces melting temperature

keith

 

Edited By CuP Alloys 1 on 22/11/2015 09:19:06

[Author]

Posts