Brass?

[Roger Mason]

Hi All.

As we all do, I picked up a length of 1/4" diameter brass rod to make a small fitting. As I was turning and drilling it I thought "These tools are blunt". It really didn't turn and drill very well, at least not in comparison to the normal brass I was expecting.

The fitting was finished and the next step was to silver solder it to a length of copper tube. When the assembly was up to temperature the solder melted and ran away from the brass fitting. Considerable heating (up to a dull red) and more anointing with flux eventually got the solder to take. Even so I don't think the solder ran between the brass and the copper - it just made a generous fillet - not what I was expecting.

I took a piece of this brass round to a friend and he agreed it didn't turn like brass. We tried soft soldering it - the solder would not wet the brass, no matter what flux was used.

So the question is - what is this brass? My first thought is aluminium bronze, but can you silver solder this?

All guesses are welcome!


Cheers,

Roger Mason, in a bright sunny, but chilly, St. Agnes.

[baggo]

Hi Roger,

It could be aluminium bronze. It tends to be a bit paler colour than brass and is definitely harder to work with. It is difficult to silver solder with ordinary flux. You need to mix a bit of common salt with the flux to provide extra chloride ions and it should then solder ok.

John

[ron]

Hi
I used aluminium bronze to make some bushes for my TR6, I doubt you would mistake it for brass it was very much lighter in colour than brass and from what I remember relatively easy to turn, unless of course there are different grades of it?
Ron

[Nigel Bennett]

I think it's likely it is aluminium bronze. You can silver-solder it; you need a mixture of aluminium flux & a suitable Easyflo (I'd use Tenacity 5) to do it. I've done it myself, and it did work, though the joint wasn't one I'd like to be holding an aircraft wing on!

However, if it's boiler fittings you're doing, I'd avoid using AB at all unless you can make the fitting complete without any brazing involved.

[baggo]

Apr 15, 2008 8:51:43 GMT ron said:

unless of course there are different grades of it?
Ron

Ron, the stuff I've got came from Ebay so it's a bit of an unknown quantity ;D

[ron]

Apr 15, 2008 13:12:15 GMT John Baguley said:

Apr 15, 2008 8:51:43 GMT ron said:

unless of course there are different grades of it?
Ron

Ron, the stuff I've got came from Ebay so it's a bit of an unknown quantity ;D

Ditto

Ron

[teakfreak]

Is aluminium bronze the same as imadium bronze? I have some 1/4" rod that came in a box marked imadium bronze. It machines miuch like brass and seems to silver solder ok, but seems to have a higher MP. I have used it on small, low pressure boilers with no problems

[circlip]

The Alluminium Bronze I machined for a bearing was as tough as a witches mammary so it must have been the same grade as Rogers. It was lighter in colour as are some lumps from a different source. Ian.

[alanstepney]

I would go along with the aluminium bronze suggestion(s).

As for imadium bronze / brass, that is a term that I havent heard in years.
From memory, and that could easily be faulty, I believe that it is brass that has been rolled several times, with something (dont recall what) added in between the layers.
(Much the same as steel was used in the middle of an iron sandwich for making swords etc.)

Probably re-melted afterwards.?

[weldsol]

Another thought for you it could have been nickel bronze welding rod (or ali bronze )as these are available up to 1/4 dia, normally sold in 1m lengths
question was either of the ends marked in any way ??

Paul

[abby]

Aluminium bronze will show a slight attraction to a magnet.

[teakfreak]

Had a look when I was in the workshop tonight, my immadium bronze is in a tube marked "Immadium bronze (manganese bronze)". Its stuff that my father was probably given back in the 1970s by someone at his evening class at the Alderlea School, Birmingham. My rate of use is such that my son is likely to inherit a fair bit too!

[teakfreak]

Had a look when I was in the workshop tonight, my immadium bronze is in a tube marked "Immadium bronze (manganese bronze)". Its stuff that my father was probably given back in the 1970s by someone at his evening class at the Alderlea School, Birmingham. My rate of use is such that my son is likely to inherit a fair bit too!

[baggo]

Apr 15, 2008 19:59:37 GMT abby said:

Aluminium bronze will show a slight attraction to a magnet.

Thanks for that tip Abby. I've just tried it on a couple of pieces I wasn't sure of and they are attracted to a magnet

[Roger Mason]

Hi All,

Thanks for all the input on this subject.

I think Abby hit it on the head when he said "Aluminium bronze will show a slight attraction to a magnet.. I tried it with a magnet, and at first I wasn't sure I was detecting any magnetic attraction, but holding the rod vertically I could get it to swing slightly when the magnet was brought near to the bottom end. Ordinary brass rod certainly didn't do that!

Now the question is - What is aluminium bronze good to use for?

Cheers,

Roger Mason, in St. Agnes.

[abby]

Ally bronze can be used for bearings although not my first choice , it naturally occurs as the selector forks in many British motor car - remember them - gearboxes , and the synchro cones , the old "knock on" wheel spinners were ally bronze , pump housings , ships propellors, It is very tough and corrosion resistant and as already stated it needs very sharp tools to machine it. I had to buy a new reamer to ream a set of jaguar selector forks I cast for some-one , the one I had would not touch it. It is not easy to silver solder, I think this is because the aluminium content forms an oxide film very readily. I tend to add my flux by dipping the heated end of the solder into the flux and then applying to the heated job - yes I'm lazy - it works for most copper alloys but not for this one , I will try out the extra salt tip from John's post , but correct flux is available from J&M. If you have any of the above applications then it's ally bronze for you , but otherwise .... from a casting point of view it melts ok but on pouring it forms an oxide tube from the crucible to the mould -it really does- castings should be bottom fed to avoid oxide inclusions , but it does take an incredible polish and chromes beautifully.

[ianengr]

Hi Rodger,

In the early 1980's my father (a motor mechanic) was working in a heavy vehicle transmission repair business. They occasionally replaced Aluminium Bronze pins from somewhere in the truck differentials, he brought one home from the scrap bin for me to see if I could make some axleboxes from it. They were about a 100 mm. long x 40 dia. they developed an unbelievable degree of work hardening on the surface. The edge of a HSS tool was instantly removed. Some years later I was supplied with a piece of hollow cast bar, which was supposed to have been gunmetal for a boiler dome ring, it to would not solder and formed a thick black skin however I don't think it was Aluminium Bronze, if I remember correctly it was softer to machine and it had a colour like half hard brass sheet. There may well be other Bronze alloys that do this.

Regards,

Ian.