This question probably has been asked before and I might have asked, who knows, but I can't find anything on it. What is the best way to clean up corroded pneumatic cylinder rams? I guess this might be asked of LA rams too. I have a few older Technic pneumatic sets, and I'm not sure the safest way to get the slight corrosion off the exposed rams. I thought about a very light sandpaper and then wipe mineral oil on them as suggested for lubing LA rams in a topic a while ago, but I'm not sure if this applies to pneumatic cylinder rams too. I'm not sure if the ram metal is the same in both, but I have an old 8464 Front Loader that I recently fitted with a forkset and even though it has the airtank and only 3 cylinders on it, they move rather creakily and slowly now as opposed to my 8455's and other Front Loaders I have that are pneumatic, but the cylinders are cleaner on those. They aren't real bad on the one, but enough that it takes more air to move the rams. My worry is if I take any meat at all off of them with say a fine sandpaper is I might get air leaks in the cylinder openings. I can expose them all fully to clean them on the model itself without disassembly. Any ideas?

Thanks

I wouldn't use sand paper unless you have some really fine 2000 grit paper used with some water for sanding paintwork, try wire wool instead. Doing that will make it clean enough for it to work as new but if you really want them shiny as new then you'll have to spend a long time at a polishing/buffing wheel. Do that with it dissasembled. Then if you want to lubricate them I would try a silicone based lubricant.

What ever you end up doing make sure the shaft of the ram is completely clear before retracting it. if you get any grit or rubbish in the seal it wont be long until you get a leak. I have cleaned them in the past using wet and dry as already suggested and the result is very good.

Thanks guys, I never thought of steel wool...that's a good idea Alasdair, I know it comes in many grades, like 0 to 0000, I'll pretty try to find the finest 0000 grade. I don't necessarily want to make them shine like brand new, this particular release of the model I have had since 2001, I just want them to move more freely and jerky or creaky. I think the corrosion on them over time just put imperfections or outcroppings on the rams. And yes, I sure don't want any foreign material going into the cylinder itself, these things are hard to find nowadays, I used to be able to buy a set of them from Lego Education US, but they have changed their lineup of pneumatic parts into kits now with only a couple of each item for an insane price and insane shipping cost, even Ground.

Alasdair - when you speak of silicone based lubricant, what exactly do you mean? I have silicone lube aerosol, but I know some of these types of sprays from what I recall from past posts can hurt ABS plastic. I know you are in the UK, and I'm in the US, so not sure of what to buy that would be safe. Somebody mentioned mineral oil for LA rams at one time a while ago, think it was after the disastrous release of the 8043 and the LA's having issues and all the recalls and the ones who already had bought them had to wait for the upgraded, lubed LA's. I have had no issues with mineral oil on LA's, I routinely use it just to keep them from corrosion I am talking of here and they also move smooth as silk after sitting a long time. Usually have to wipe off a bit of dust or the occasional spider-webbie but that's about it. But I'm not sure if this is safe for the inside of the pneumatic cylinders when the rams are retracted?

Thank you for your input,

Eric

Well, i'm Allan, not Alasdair!

Anywho, I wouldn't use mineral oil as it can swell and soften the rubber seals. Silicone oil is probably the best easily accessable oil for this (there are better ones but tend to be harder to get and more expensive) but the propellant used in a spray version might also damage the seals. Copied from another site:

"However, take in mind that silicone sprays with petroleum in them can be bad for rubber parts. Some silicone sprays are also below 7 on the PH scale which means they could be corrosive. It is safer to always use a food grade silicone which ensures me of PH neutrality. If you get a silicone spray that is “Food Industry Approved”, then it probably won’t contain petroleum components and also guarantee that the PH is neutral."

I have never lubed them myself but if I did i'de probably try this some Core-RC CR228 Silicone Oil in a fairly light grade or a food safe silicon spray.

Some people have also suggested the use of olive oil (definitely food grade )

Well, i'm Allan, not Alasdair!

Anywho, I wouldn't use mineral oil as it can swell and soften the rubber seals. Silicone oil is probably the best easily accessable oil for this (there are better ones but tend to be harder to get and more expensive) but the propellant used in a spray version might also damage the seals. Copied from another site:

"However, take in mind that silicone sprays with petroleum in them can be bad for rubber parts. Some silicone sprays are also below 7 on the PH scale which means they could be corrosive. It is safer to always use a food grade silicone which ensures me of PH neutrality. If you get a silicone spray that is “Food Industry Approved”, then it probably won’t contain petroleum components and also guarantee that the PH is neutral."

I have never lubed them myself but if I did i'de probably try this some Core-RC CR228 Silicone Oil in a fairly light grade or a food safe silicon spray.

My bad Allan, Alasdair responds to my posts a lot and I was pretty tired bug-eyed when I replied...

Some people have also suggested the use of olive oil (definitely food grade )

Tried olive oil couple years ago...most of my setup is in an insulated garage, but it still tends to get rather cold in there come mid-fall through mid-spring, besides the times I'm actually out there and then I run propane and electric heat, but the olive oil congealed into clumps...would be nice if I had room inside but I've got 10 30"x30" card tables on each side of the garage and that definitely wouldn't fit inside well...mineral oil always worked well on my LA's, but like was said by Allan it could degrade seals, good thing was on the LA rams it stayed 'liquified' during the winters, thus smooth operation...I suppose once I get to cleaning the pneumatic rams in question with the steel wool it might eliminate catching or creaky operation...