Help... WD-40 or Not for Sinar P2 cylinder?

[Dustyman]

So my Sinar P2 8x10 back has an hydraulic cylinder to dampen the closing action.
If unused for a day the cylinder's plunger gets temporarily stuck in the "in" position (see attached pictures).
Opening and closing the back a half dozen times is enough to get the plunger to pop out and work properly for the rest of the shooting session.

There is no apparent gunk on the chrome plunger. I cleaned it with denatured alcohol, and then with naphtha. I tried working the naphtha into the cylinder by opening and closing the back a bunch of times. Problem persists.

I think I need to use some sort of penetrating chemical that would seep deeper into the cylinder to help remedy this situation.
WD-40? If not, then what?

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[Peter De Smidt]

WD-40 isn't a long-term lubricant. I wouldn't use it. Perhaps lightly waxing the cylinder might help. The issue is whether whatever is used would negatively interact with the hydraulic fluid. Hopefully, someone who knows more about that will chime in.

[Dustyman]

Thx Peter. I tried a bit of white lithium grease which didn't fix it.
I think the issue is to be able to lubricate the end of the plunger that can't be seen (it's within the cylinder).
That will require something very thin and penetrating.

I'm hoping others will chime in.



WD-40 isn't a long-term lubricant. I wouldn't use it. Perhaps lightly waxing the cylinder might help. The issue is whether whatever is used would negatively interact with the hydraulic fluid. Hopefully, someone who knows more about that will chime in.

[Leigh]

WD-40 is paraffin (wax) in a solvent carrier.
After the carrier evaporates, a thin film of paraffin is left on the surface.

The paraffin would be too heavy to work as a good lubricant for something with such small closing force.

You might try sewing machine oil.

- Leigh

[Vaughn]

If you were next door, I would let you borrow my bottle of magic Kodak Special Lubricating Oil. The smallest amount cures everything it touches. Actually I would not let you borrow it -- I would come over and anoint your device myself.

In reality, an old 1 oz bottle of Kodak's lubricant for their movie cameras and projectors ("This is the only lubricant that should be used on Kodascope projectors"). Instead of a dropper in the cap, it has a thin rod to deliver the drop of oil where one needs it. I know I have used it a few times over the years, but can't remember exactly for what...just that it worked and I haven't had to mess with whatever again.

[Drew Wiley]

WD-40 is a junk lubricant. It's traps water underneath it instead of displacing it. If you want an analogous-use product that is good quality, I recommend LPS Premium no.1. Give it overnight to outgas before being around film. And don't confuse it with their electronics parts cleaner!

[Dustyman]

Anyone have experience with Swiss-made Moebius Oil? It's apparently a highly regarded watchmakers oil.

[Eric Woodbury]

Either a silicon lube or Teflon would be excellent. Bike shops have the best stuff. WD-40 stands for water displacement and evaporates. I'd use butter before WD-40. I like the wax idea.

[Drew Wiley]

Just don't get silicone on the bellows or a wooden camera. Best to avoid that stuff. I forget what I originally used on my Sinar. It was some esoteric cold-weather lube that worked wonders. Still have it, but can't remember the name. Some of those older miracle lube formulas contained actual sperm whale oil, which tended to be replaced with jojoba derivatives, though reserves of the real deal were available for small quantity applications long after most commercial whaling ended.

[Greg]

Have had great luck with DU-PONT MULTI-USE with teflon Lubricant. Many years ago used paraffin (wax)... worked until temperatures got below freezing.

[IanG]

Is it not possible to remove the part and service it properly ? Strip it down clean it and re-assemble/re-fill.

WD-40 is something of last resort, I only use it if nothing else works, I've freed up old shutters with it however I've then made completely sure all traces have been removed. I use sewing machine oil sparingly for lubrication, often diluting it with IPA (Iso Propyl Alcohol).

Ian

[pjd]

As others have said, WD-40 might not be a good idea, it'll be difficult to fully remove if it doesn't work.

About Moebius oil, there are many varieties. I bought a tiny bottle of Moebius oil (forget which one, and can't find it right now) a few years ago - it seems high quality, but the oil I got was a bit more viscous than I wanted. In short, be careful about what you buy, it's not cheap stuff.

[LabRat]

Some of those type of cylinders are not oil filled, but use air??? (Or maybe gas filled, but probably not) Check the piston shaft area and around the body to see if there is a trace of oil that might have escaped over time, and if so, the fluid might have to topped off... If air operated, the piston, walls, and seals would need cleaning sometime... Oil cylinders would move very slowly normally, but air moves a little faster but also smooth... Try to figure what kind of cylinder it is first...

Steve K

[David Lobato]

A light film of Vaseline might be what's needed. It stays in place better than oil would.