I've got a couple of cylinders where the rods have rusted from being exposed the last few years. Can the rods be sanded down and polished in any way to allow me to use the cylinders only a few more times? They are used to prepare a large piece of equipment for transport, and if I could get a half dozen more cycles out of them I'd be done using them most likely.
If this can be done, what is the best way to do it? Thanks,

Justin

Is it the cylinders are chromed?
if it is not chromed then u can pilish it & send it for metal spray and use for long time.

Yes the cylinder rod is chromed, or at least appears to be. That's what has me concerned about being able to do this.

Justin

I assume that the extend side of the cylinder is doing the work rather than the retract?
If so I'd give cleaning the rust off the rod a whirl....the worst that could happen IMO is an oil weep around the rod seal.

Seems like poor quality plating process ..no nickel underneath the chrome .. it shouldn't be rusty...Retracting the cylinder will prevent rod corrosion like this taking place.


Regards Woody

This message has been edited. Last edited by: Woodygb,

Yes, under normal circumstances the rod is extended. It is only retracted for transport.
What should I use to clean this with?

Justin

You could try wire wool and oil.

How big are these cylinders?

Regards Woody

Pretty good size. I would need to look closer at them, but I would guess around a 5" diameter with a 2 - 2.5" rod.

Justin

If it's chromed, it shouldn't be hard to clean off, the rust is bleeding through the micro cracks in the chrome, which is known to happen in corrosive envrionments. The only way to stop it is to nickle plate the rod, then chrome plate over the nickle.

quote:

if I could get a half dozen more cycles out of them I'd be done using them most likely.

If your not that woried, just get a length of abbrasive cloth that you can hold in both hands, and polish away, back it forth (not along the length, but radially. You need something pretty fine though, 300 - 400 grit would be good, try not to go bellow 220.

Or, you could pull the rod out, take it down to a cylinder repair shop that has a rod polisher.

quote:

If it's chromed, it shouldn't be hard to clean off, the rust is bleeding through the micro cracks in the chrome, which is known to happen in corrosive envrionments. The only way to stop it is to nickle plate the rod, then chrome plate over the nickle.

Note on Hard Chrome:-
"It is a common misconception that chrome plating provides corrosion protection. This is not the case, only slight protection is given. Hard Chrome is porous at the microscopic level, which can let moisture and chemicals through to attack the base material. If the item is to be used in a damp environment, a layer of Nickel plating is required, prior to hard chrome plating."

It would be nice if all cylinder manufactures followed good engineering practice on the assumption that their product might encounter "a damp enviroment" .... it would seem that some don't.

Regards Woody

Well, here are the results. I got some 320 grit sand paper and went at it until my arms about fell off, and then came back with some 420. Once it was polished it was hard to get my camera to focus on it, so you can't see it as well, but what are your guys opinions? Ok to use now? It feels pretty smooth.

Before
http://i231.photobucket.com/al...04-20091025-1356.jpg

After
http://i231.photobucket.com/al...07-20091025-1428.jpg

I've got a thin layer of grease on it now to protect it until it's used.

Justin

Looks ok to me.

Regards Woody

ParkerFly,

It doesn't look very good, surface finish of the rod does effect the life your cylinder seals. I will suggest that you either send them back to the manufacturer or ask him for rework instructions. Its very common that people leave cylinders in the inventory for a longer time without excercising the rods and they end up as you have shown.

quote:

Originally posted by SDK:
ParkerFly,

It doesn't look very good, surface finish of the rod does effect the life your cylinder seals. I will suggest that you either send them back to the manufacturer or ask him for rework instructions. Its very common that people leave cylinders in the inventory for a longer time without excercising the rods and they end up as you have shown.

Note that Parkerfly only requires 6 more cycles.

Would alodine be of help to minimize further corrosion?

Sure 6 cycles doesn't seem to be all that many, but what is the time frame in which the 6 cycles will be performed?

The coating the rod with grease will only be good for one stroke, since the rod seal and/or rod wiper will clean it off when the rod is retracted -- unless they have been torn/worn by the rust previously. Therefore, if the rod is going to be exposed for an extended period of time in between cycles you will need to recoat the rod with grease to keep the exposure to air, water, etc. to a minimum.

If you'd like to get more life out of the cylinders, you could. If the cylinders are of a tie-rod or non-welded construction, they can be rebuilt. A new rod can be put into them along with new piston and rod seal/wiper seals as well.

In today's economy -- and environmentally -- it beats throwing away the cylinder and buying a new one.

This message has been edited. Last edited by: Jeff Klingberg,