savageseadog
Well-Known Member
Which is the best for brackets and the like.
Silicon Bronze
Aluminium Bronze
Phosphor Bronze
Other?
Silicon Bronze
Aluminium Bronze
Phosphor Bronze
Other?
Best Bronze Underwater
- Thread starter savageseadog
- Start date
vyv_cox
Well-Known Member
A very difficult question to answer. What do you mean by best? Silicon bronze has good strength and corrosion resistance and can be welded. Aluminium bronze has excellent corrosion resistance but is difficult to cast and some grades are unweldable. Some alloys are hardenable by heat treatment and in general it has good fatigue resistance. Phosphor bronze is generally used in the cast condition, has very good compressive strength and load carrying capability.
I would not say that any of them were great as 'brackets and the like', as more useable, available and cheaper alternatives are probably just as good.
I would not say that any of them were great as 'brackets and the like', as more useable, available and cheaper alternatives are probably just as good.
savageseadog
Well-Known Member
[ QUOTE ]
I would not say that any of them were great as 'brackets and the like', as more useable, available and cheaper alternatives are probably just as good.
[/ QUOTE ]
What alternatives please?
I would not say that any of them were great as 'brackets and the like', as more useable, available and cheaper alternatives are probably just as good.
[/ QUOTE ]
What alternatives please?
vyv_cox
Well-Known Member
The much maligned Admiralty brasses and Naval bronzes are widely used for skin fittings, propellers, P-brackets and loads of other fittings. Ok, they don't last for ever but they don't cost a bomb either. My P-bracket was fitted for 20 years but when I cut it open there was no sign of any serious corrosion.
There is now a version of brass known as DZR, standing for de-zincification resistant, that is marketed as Tonval. This should outlast most other copper-zinc alloys.
Most of us have prop shafts of 316 stainless steel. Despite the widely-given advice not to use stainless steels underwater, the fact remains that they mostly last almost indefinitely.
All of these will benefit from having an anode fitted, reducing the cost of the installation. Even mild or carbon steels can be used underwater very effectively provided that sufficient anodes are fitted in the correct placement. Some of those North Sea platforms, mostly made of steel, have been out there since the 1970s.
Copper-nickel, if you can find a supplier, is available as sheet, bar, rod, etc and can be formed, welded, drilled etc very readily. It is excellent underwater.
There is now a version of brass known as DZR, standing for de-zincification resistant, that is marketed as Tonval. This should outlast most other copper-zinc alloys.
Most of us have prop shafts of 316 stainless steel. Despite the widely-given advice not to use stainless steels underwater, the fact remains that they mostly last almost indefinitely.
All of these will benefit from having an anode fitted, reducing the cost of the installation. Even mild or carbon steels can be used underwater very effectively provided that sufficient anodes are fitted in the correct placement. Some of those North Sea platforms, mostly made of steel, have been out there since the 1970s.
Copper-nickel, if you can find a supplier, is available as sheet, bar, rod, etc and can be formed, welded, drilled etc very readily. It is excellent underwater.
fiddler
New Member
Re: Best Bronze Underwater is NOT TONVAL
Tonval is absolutely NOT Bronze. It is BRASS and the Coastguard have issued a warning that it is NOT for use underwater. See the MCA report on the near-sinking of "Random Harvest", and also ASAP's very useful materials spec.
Tonval is absolutely NOT Bronze. It is BRASS and the Coastguard have issued a warning that it is NOT for use underwater. See the MCA report on the near-sinking of "Random Harvest", and also ASAP's very useful materials spec.
Victorious
Well-Known Member
[ QUOTE ]
Most of us have prop shafts of 316 stainless steel. Despite the widely-given advice not to use stainless steels underwater, the fact remains that they mostly last almost indefinitely.
[/ QUOTE ]
A prop shaft lives in very disturbed water and thus gets some oxygen.
It is a very very very different application to a keel bolt of other fastening
Most of us have prop shafts of 316 stainless steel. Despite the widely-given advice not to use stainless steels underwater, the fact remains that they mostly last almost indefinitely.
[/ QUOTE ]
A prop shaft lives in very disturbed water and thus gets some oxygen.
It is a very very very different application to a keel bolt of other fastening