sjms wrote:
No, that's corrosion. White powder filiform type under the paint. Pretty much invasive and almost impossible to get see much less get at because of the "protective" paint. Salt/acidic environment based. That grey black crackle paint hides it well.
And is a non warranty issue. would happen on any Mg alloy based tripod that spent time in a salt/acidic environment.
There are tripods out there that are constructed of much more resistant materials and that are built with better overall design and potential longevity
I have a Gitzo explorer, and after a few years the paint on the central casting started bubbling and flaking off on large areas, and the metal underneath is turning to powder. I have not once used it near salt water, so I do not know what is wrong. In many respects it is an excellent tripod, but I did not expect corrosion. Sadly the warranty is now expired, but when I first contacted them, they said to send it in. The problem is that doing so would cost a small fortune, and they might say "damage caused by user" even though I cannot see how that was the case.
peter_n wrote:
^ It could have been an airborne contaminant.
More likely water or salt water if it really is MgO from an Mg alloy. An alloy that oxidises so readily seems like a fairly poor choice of material to me though. I wouldn't pay the Gitzo premium for that.
sjms wrote:
the adjust/lock couplings on a Gitzo leg set are anodized aluminum alloy. on their CF tripods if it has the paint job on it its MG alloy.
Yes, I meant the painted magnesium castings at the top of each leg, not the things that join leg segments. The tripod seems to work perfectly after more than 5 years, once I learnt to tighten the leg angle adjustment. I was surprised that it looked so nice, and then it doesn't, due to corrosion.
15Bit wrote:
More likely water or salt water if it really is MgO from an Mg alloy. An alloy that oxidises so readily seems like a fairly poor choice of material to me though. I wouldn't pay the Gitzo premium for that.
Yes, it strikes me as odd that people use Mg when it does react so strongly with other substances. Aluminium is pretty much inert thanks to the surface oxide layer.
sjms wrote:
it does not oxidize so readily if properly alloyed, protected and used.
Which is it here? Bad material choice, poor coating/painting or user error?
I would not buy a tripod for several hundred dollars and expect a couple of paint chips to result in it's demise, so i think Gitzo holds the responsibility here.
That would require a little more analysis?
What is thought and is reality can be somewhat different. I am one not to decide fault generally without it.
I made my choice a long time ago for what I considered a better investment.
Personally I have not liked Mg Alloy since seeing an APC hit a mine and open like a tin can.
But seriously, it's completely unscientific but I have a theory/phobia about Mg Alloys - that they can shatter on impact.
LeifG wrote:
I have had a Benbo aluminium tripod for at least 10 years, and although paint has flaked off, there is no corrosion. I just wish it was lighter.
As to Mg alloy vs explosive kinetic energy I really thing that just about any material used in tripods today would be at minimum "challenged" by said forces
sjms wrote:
As to Mg alloy vs explosive kinetic energy I really thing that just about any material used in tripods today would be at minimum "challenged" by said forces
Quite. I'm not sure it's a very relevant test methodology for tripod application either - might as well complain that it melts several hundred degrees lower than steel. Another irrelevant test unless you are planning to do time-lapse in a volcano.
The issue here is really about corrosion and whether the material choice is correct for the application.
15Bit wrote:
Quite. I'm not sure it's a very relevant test methodology for tripod application either - might as well complain that it melts several hundred degrees lower than steel. Another irrelevant test unless you are planning to do time-lapse in a volcano.
The issue here is really about corrosion and whether the material choice is correct for the application.
just having a little fun with Mr Mo's comment on an APC interacting with a mine. it was relevant to his statement.
