Generally for boiler work you need oxygen free grades of copper which are C103 & C106. If you use a grade that is not oxygen free there is a risk that the heat from soldering can make the oxygen boil and that causes fine cracks in teh copper known as oxygen embrittlement.

Have a read of CuP alloys site, parent material explains it

J

hi bill,

C101 has been used for many years for silver soldering with propane/gas blowlamps/paraffin blowlamps. it is NOT suitable for use with TIG welding, and probably the reference in the excellent CuPalloy's link from Jason is in respect of use with oxy-acetylene?

i agree with Jason that C106 is preferable. i dont know quite what you mean re Macc Model's pricing as in my experience all Joe's copper boiler material is C106 and is what ive used from him for quite a few years and quite a few boilers, with i might add excellent service from Joe with my sometimes odd sizes and requirements.

check what grade copper your club boiler inspector requires.

cheers,

julian

Edited By julian atkins on 04/03/2015 23:56:09

To add to what Julian has stated about copper grade, indeed the tube Joe at Macc models sells is deoxygenated but unless things have changed recently the plate isn't, so you cant tig one to the other. I know because I tried, and can still hear the awful cracking noised as it cooled in my head! And there's nothing diabolical about using plumbing pipe either! (don't lets start that debate again, but people have and do use it with no ill effect).