Thread: brass vs bronze

Originally Posted by YarrD

Hi all

I have a yacht fitting that is worn and needs building back up with filler rod...I can't tell if is brass or bronze. I am assuming bronze as I think I read somewhere that brass and saltwater don't go together as well as bronze. In salt environment, I read that brass oxidises with pinkish hue. My fitting is not pinkish but how do I tell for sure if I have bronze or brass fitting or doesn't it matter melting point-wise?

David

What sort of filler rod are you intending to use?

Brass drills easily, bronze doesn't.

Most non ferrous ship fittings are brass. Bronze is expensive and total overkill for most non wearing applications.

Rob

And of course Gunmetal is both a brass and bronze at the same time

I was going to use braising rod -pre flexed things. The fitting is a wear part - small worm drive "gear box" that I crank with a handle to furl the sail. I will see how hard it is to drill.

I meant prefluxed rod...made by CIG

Originally Posted by YarrD

I meant prefluxed rod...made by CIG

Auminium bronze as used by plumbers for joining copper pipes ? Has a yellow end on the rod.

If you use Manganese (hard brazing ) bronze you will probably melt the item you're fixing - meant for steel and cast iron ( has a similar melting point to admiralty brass and regular bushing bronze).

yes, there is a risk that I melt the parent metal. I think I will not take the risk. I am now sure that is bronze fitting (although it has a chromey lustre, is gold in middle) and is quite hard to drill. The little gearbox with worm drive is also same material and surprisingly little worn after 25 years. It seems to be quite tough stuff and unaffected by years at sea which explains its original deployment for this. Today, stainless steel would be the automatic choice.

I know Aluminium bronzes will go silver when exposed to high heat >600C I'm not sure what other bronzes will do, but brass I use normally goes copper (pink hue) not silver with high heat.

Originally Posted by YarrD

I am now sure that is bronze fitting (although it has a chromey lustre, is gold in middle) and is quite hard to drill.

The chrome lustre suggests it is aluminium bronze. This is a lower melting point bronze and is used to cast ships propellors and for other marine use.

That said, it would be unwise to try to build it up, even with yellow tip rods.

Rob

Originally Posted by nearnexus

The chrome lustre suggests it is aluminium bronze. This is a lower melting point bronze and is used to cast ships propellors and for other marine use.

That said, it would be unwise to try to build it up, even with yellow tip rods.

Rob

I think tig with aluminium bronze would be fine?