Is it bronze or brass?

[kalanka]

I have removed the raw water strainer assembly from a Sadler 34 to reseal the 1/2 inch thru hull. To do this I had to cut the flange off the thru hull. I suspect it is at least 30 years old but there is no sign of corrosion - it is properly wired to an anode. I was expecting the fitting to be bronze but the new cut looks very yellow and brass like. The actually strainer is a Guidi Tirreno and scrapes to a similar shade of pale yellow.

Can I tell bronze from brass on colour alone? Would you replace the thru hull with bronze (as planned) or go for de-zincified brass? Thanks

 

[Tranona]

Difficult to tell visually, but suspect from age it will be bronze. Replace with either DZR or bronze. Absolutely no need to connect to an anode. An anode is only needed when 2 dissimilar metals are in contact under water such as a shaft and a propeller. A through hull in GRP is a single material so does not meet this condition.

 

[earlybird]

Can I tell bronze from brass on colour alone? Would you replace the thru hull with bronze (as planned) or go for de-zincified brass? Thanks

Some bronzes are quite yellow, so identification by colour is uncertain. DZR brass, (NOT de-zincified ), is widely used, but bronze is a top choice if available, but at extra cost. I don't think that I'd normally connect a skin fitting to an anode.

 

[vyv_cox]

Colour is a very good guide. Americans call bronze 'red brass' (no idea why but it does illustrate the colour difference). Lots of examples here Brasses and bronzes

 

[lustyd]

Would you replace the thru hull with bronze

Trudesign is the go-to these days for most folk. No corrosion, not even on the ball, no dezincification, no condensation inside, no maintenance. The only downside is they don't fit in some older vessels, but otherwise they're better in pretty much every way for a composite boat and will last as long as the boat.
Certified for use anywhere in non-commercial boats, and commercial only excludes engine space (pointlessly, the hose itself has a much lower melting point).