colm, it's fine, we electrolysed ours.

I'm not sure what they're made of but if it's not cast steel of some description then I'm a chinaman.

nahow den mithta bluthift, <in best Chinese accent>

Did you block up the fluid holes and leave the pistons in?

Ned,

Me and my callipers, well infact all my car stuff are about 8 miles apart and i have no where to use said "tool" in this weather, i have had the ones on my finished car apart an many occasions but was unsure of their suitablity for the electrolysis method.

No, ours are completely stripped for rebuild.

I wouldn't care to comment on what might happen to any rubber bits etc and the risk of water contamination if you did them that way. We knew we would be able to clean ours and flush them with meths and dry them before reassembly.

side note, I'm not sure if the bleed nipples were anodised or something, but I took one that had a kind of yellowy oily sheen kind of look on the bits that weren't rusty, and electro-de-rusted it as a test. the rust got attacked but apparently so did this yellowy coating, those bits were shiny silver (well steel) afterwards.

quote:

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Originally posted by blueshift
I'm not sure what they're made of but if it's not cast steel of some description then I'm a chinaman.

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SG?? UTS??? speak english man!

weeeel.. isn't cast iron just a form of steel with lots of carbon in it?

hanging on to my british passport for dear life..

its the other way around methinks - iron comes from the ground and the 'alloy' steel is made by adding carbon and other stuff to it

atb

steve

I was under the impression that wrought iron was pure iron, then as you add carbon you go through mild through high carbon steels, then cast iron which has quite a lot of carbon in it.

rather a dim memory though and may be utter tosh.

Moulten iron is very viscous, when high levels of carbon is added it lowers the viscosity to enable complex castings to be make, I think the carbon is in the form of graphite. The cast iron is not strong but does not resonate (probably absorbs shocks instead of transmitting it), thats why Piano frames are made from it.

In another thread about welding cut off parts of sierra bottom arms, there is a big discussion about welding to cast iron - the bottom arms are cast steel, not iron. Cast steel has other metals added to make it castable and to improve the strength. You can weld to most cast steels without problems as long as you use the correct rods (MMA). The only things made of cast iron on a car that I know of are some exhaust manifords, some brake cylinders and things like alternator brackets on older cars

What about cylinder blocks, liners, heads some crankshafts , most conrods, flywheels many crankpulleys, type 9 gearboxes, some diff housings brake disks and many other parts.
Most of which are SG or in other words spheroidal graphite iron .This is a grade with round particles of graphite as its name inplies and has a much closer structure than plain cast iron which has a jagged grain structure and is much weaker.
Paul

quote:

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Originally posted by Mark Allanson
The only things made of cast iron on a car that I know of are some exhaust manifords, some brake cylinders and things like alternator brackets on older cars

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SG is the marking on ductile iron, which is annealed after casting. It can be cast much thinner than grey iron and is a bastard to fettle after heat treatment as it bends instead of shattering as we found out on the foundry end many years ago.

yours, Pete.