MicrobeHunter.com Microscopy Forum

Can anyone please recommend a grease for brass racks and mechanical stages on the vintage scopes?

Three months ago I lubricated the stage and condenser of my microscope with white Lithium grease. OKS 470, I picked it from the hardware store, very inexpensive (and I only use a tiny fraction of the smallest tube that I could buy). Appears to the job. Parts move smoothly.

Micscape had an article on greases a few years ago, let me see if I can find it...
Here it is:

http://www.microscopy-uk.org.uk/mag/ind ... wlomo.html

I have read others using the Nye products with good success. I need to order some myself for one of my LOMO stands.
Good luck
CE

Somewhere, I have a list of greases used by AO. Most were from some small companies, in the vicinity of Buffalo, although a couple were Mobil, and at least a couple, proprietary blends. I will dig that out and post it.

Lately, I have been using sometimes, Dow Corning, 1 11. for some applications and Nye 362 HB for others, as well as some lithium and lighter greases for certain things, like ball tracks etc. Where tack or clutching is required and especially on cork or other clutchpads, the two former greases noted are good.

Just a note. Nye, formerly produced a nice hobby kit, in a box with 3 cells. The middle has a 2 oz. tube of 362 HB, with the flanking cells containing each, a 2 oz. bottle with a needle applicator of PP269 light oil and MM176F heavy oil. It sometimes sold for as low as 30.00, on ebay. The kit has been discontinued and there will be no more stock. There are however, possibly 5 left at Nye's small volume distributor, Tai Lubricants. I just refilled, since my two bottles of oil, mysteriously disappeared, in the fall. I think someone really fancied them. Price was 40.00, which in my opinion is a great buy.

Thank you all so much!
I’ll look around for these.
Jim

For dovetail guides and other lubricating points with a lot of surface the grease should be quite soft. Special greases for this application contain animal fats that make them stick better to the surfaces.
With stages one tries to put the damping in the knob and have the stage itself move freely.
These types of grease are not used in mass applications so availability is not really good and prices are high.
I don't have a suggestion where you could buy these special greases in your area. You might look for watchmaker supplies, maybe they sell similar greases.

Bob

Found some white lithium grease to try.
I will comment further when it arrives.
Thanks again!

So far the lithium grease works just like I wanted. Smooth movement with a little resistance to counteract drift. Thoroughly cleaned any old grease away with acetone.
If anything ugly happens I will report, but I don’t expect it to.

Incidentally, I restored the smooth movement of the push-rod on my just-received trinocular head for the GFL with the lithium grease mentioned above, after thorough cleaning of the brass tracks with light petroleum (not acetone, I try to avoid the powerful solvent acetone).

From my eyperience white lithium grease is best for applications where water resistance is needed (it raining again here...). I use it for bicycle and motobike parts mainly. From my experience it doesn't adhere very well to the surfaces and feels somewhat grainy. Compared to instrument greases it works for microscopes but only on an acceptable level. When I only had what's available in diy markets etc. I would prefer transparent yellow bearing grease. On many places of a microscope this is just good enough.
For some applications machine way oil (68 and 220 viscosity) is useful and not difficult to obtain.

To keep this in perspective: It is most important to remove sticky and hard old grease to avoid wrecking the gears with too much force. The choice of the new grease then only makes the difference between a good working and a really nice working instrument.

Bob

I spent some time researching this when I was rebuilding my AO microscopes. By way of compromise (short of paying $$$ for the built-to-task specific greases) I have been using Super Lube Synthetic grease.

https://www.amazon.com/Super-Lube-21030 ... super+lube

I found a number of recommendations for it and I was able to find it locally which is always a bonus (Ace Hardware).

The price of the SuperGlue from Amazon is about $39. The small print on the package says that it contains PTFE. PTFE is indeed a superb lubricant since its friction coefficient is tiny. That explains the price.

Some ball tracks and some rack and pinion mechanisms are relatively undemanding but I would caution against using standard general "slippery greases" for mechanisms that need a clutching action, such as focusing and most xy controls. Damping greases are required .

apochronaut wrote: Lately, I have been using sometimes, Dow Corning, 1 11. for some applications and Nye 362 HB for others, as well as some lithium and lighter greases for certain things, like ball tracks etc. Where tack or clutching is required and especially on cork or other clutchpads, the two former greases noted are good.

The Dow Corning 111 is very reasonably priced on Amazon. I might give that a try for my LOMO XY mechanism which has gotten quite stiff. Thanks
CE

When cleaning and relubricating xy stages I like it best to have the stage parts move with little friction and have damping in the controls of the stage. From my experience this gives a better feel for the movement of the slide. So the stage itself can be greased with bearing grease but the knob would prefeably be greased with instrument grease with damping properties.

I'm preparing to service my recently acquired vintage Carl Zeiss Jena Amplival microscope. I note that Nye Lubricants still makes the 795A synthetic damping grease.

What would you recommend as alternatives to the PP269 light oil and MM176F heavy oil?

-----------------------

Just a note. Nye, formerly produced a nice hobby kit, in a box with 3 cells. The middle has a 2 oz. tube of 362 HB, with the flanking cells containing each, a 2 oz. bottle with a needle applicator of PP269 light oil and MM176F heavy oil. It sometimes sold for as low as 30.00, on ebay. The kit has been discontinued and there will be no more stock. There are however, possibly 5 left at Nye's small volume distributor, Tai Lubricants. I just refilled, since my two bottles of oil, mysteriously disappeared, in the fall. I think someone really fancied them. Price was 40.00, which in my opinion is a great buy.[/quote]

The oils are less critical than the greases.
Main problem of the Microval series is grease that hardens up completely and makes th instruments difficult to dismantle.

When choosing lubricants there are some criteria:
- Quick movement or big areas - oil or light grease
- Dampening: Special instrument greases
- Good adhesion: Animal fats and machine way oils
- No evaporation (it sets on lens surfaces)
- Good long term stability

When you take sewing machine oil for the quickly moving parts and machine way oil (68 or 220, the latter less fluid and better sticking) for better adhesion on slower moving parts you will be fine.

Obviously there are some trade secrets and problems of availability when it comes to instrument lubricants. Otherwise it would not have happened that THE microscope company Carl Zeiss Jena had made such a mistake.

I prefer Super Lube. Others have mentioned it. I found Habor Freight (in the USA) sells tubes of it. I bought a 14 oz tube for $8 on amazon several years ago. Expect I will never run out. A lot of lithium greases can harden with time, Super Lube should not.

mnmyco

MichaelBrock wrote:I spent some time researching this when I was rebuilding my AO microscopes. By way of compromise (short of paying $$$ for the built-to-task specific greases) I have been using Super Lube Synthetic grease.

https://www.amazon.com/Super-Lube-21030 ... super+lube

I found a number of recommendations for it and I was able to find it locally which is always a bonus (Ace Hardware).

This is what I finally chose, and it works great for course focus racks. Not too sticky and not too slick.

I found a lubricant manufacturer/supplier recommendation from Kay Hoerster on the German Mikro-Forum for this company - Losimol. They provide technical specifications for their lubricants. http://www.losimol.de/en/home/

Thanks for the link, Peter

MichaelG.

I've used Dow M-kote 44M as a medium grease (NLGI #2 consistency, same as SuperLube). It's a white, silicone, high temperature grease. Far as I can tell the main plus is that, as a high temperature grease, it is less likely to either have volatile fractions evaporate or stiffen up in time. That makes it good for things like the slides in trinocular heads. I just used it to lube the fine focus gears in a Nikon Optiphot. It's not as sticky as the original grease, but in this case I wanted very free movement due to the fine focus gear problems these often have. I kept a heavier grease on the coarse focus bits. We'll see how it all holds up.

Dow also makes a silicone grease for helical focus mechanisms that's good for focusing eyepieces.

The main minus of a silicone grease might be that it likely requires complete removal of the old grease, since silicone and traditional greases are often incompatible.

I have often wondered... when greases are incompatible, how exactly does this manifest?
CE

One issue is that they separate and don't provide consistent (to spec) lubrication. I've also been told that given a wide variety of thickeners used, in rare cases they can interact and sort of lock up.

Does anyone have experience with Dow Corning Molykote 7348 for the mechanical stage X-Y motion or condenser focusing rails ?
it is a dark pink/brown grease, described as:
"High temperature silicone grease for rolling-element bearings.
Applications – Used successfully on bearings in driers and on conveyor chains of wood coatings plants. Also suitable for sterilizers.
Features – Low evaporation; High oxidation resistance; Good long-term lubrication; High drop point; Water-resistant.
Composition – Silicone oil; Lithium complex thickener; Anti-oxidant; Solid lubricants."

Does anyone have experience with Dow Corning Molykote 7348 for the mechanical stage X-Y motion or condenser focusing rails ?

No, but I personally would stay away from silicone oils or greases for anything around optical equipment, since it gets everywhere and pretty soon your equipment has that slippery silicone feel, which is tough to get off, and might transfer to places where you don't want it (lenses, etc). The same goes for all 'Molykote' products; they probably contain molybdenum disulphide, an extreme-pressure anti-seize additive that also gets on everything and should be totally unnecessary in microscopes.

For dovetails and focus gears and parts, I like the synthetic damping grease Nyogel 767A. A 50 g tube will last a long time.

I'm far from an expert on greases, but can add a bit to the discussion.

A grease has either an petroleum or synthetic oil base plus a thickener to keep it in place. Lithium, silica, and clay are examples of traditional thickeners. PTFE (Teflon) is a more recent one. Silicone can apparently be both a base (synthetic) oil and a thickener.

The higher the "NLGI" number, the thicker the grease. NLGI #2 is pretty common and it's about the consistency of peanut butter. There's more to this than just consistency though -- things like shear rate.

As an example, Nyogel 767a is a silica thickened NLGI 2 fairly heavy grease meant for damping. Compared to other NLGI 2 greases the consistency seems much more like putty (good if you want damping) than either the lithium or silicone based greases I've used on various instruments and machines.

What's wanted for optics, is something that stays put (a grease), isn't volatile (otherwise lighter fractions might condense on lenses), and is very resistant to oxidation over time. A combination of volatility and oxidation is what causes old microscope greases to harden up over time.

Personally, I'm not sure why a silicone based grease would be more likely to get all over anything than any other grease. I've heard both yes and no that's it's harder to clean off optics, though. Thankfully, haven't run that experiment yet on my own objectives, eyepieces, prisms etc.

McMaster-Carr (the industrial supplier) has a page on greases listing things like heat and water resistance and oxidation. I'd suspect that heat resistance is pretty well correlated with low volatility. Just looking at the McMaster quick guide, it looks like calcium sulfonate (an old standby for extreme pressure applications) might (?) be an ideal thickener for optical mechanisms, but at a cost.

Here (an an example) are the Nyogel 767a specs: https://shop.newgatesimms.com/wp-conten ... l_767A.pdf

Thanks PeteM and wporter for the info. Good to know.

Personally, I'm not sure why a silicone based grease would be more likely to get all over anything than any other grease.

You're probably right. I guess what I don't like about silicone-based lubes is the persistent slick feel, even after wiping off with a rag, say (though the silicone feel can be removed with certain solvents or detergents.) Whereas with synthetic hydrocarbon lubes, the feel is more natural (probably because it's similar to skin oils), so it doesn't seem as persistent, though it may be.

Because of past experience, I look upon silicone lubes as more for certain applications requiring water-and-heat-resistance (machinery rubber o-ring lube, e.g., on engine cylinders & heads), chemical inertness (stopcock and vacuum system grease), and long-term homogeneity. Plus, I suspect that silicone lubes have worse performance in wear-tests (not that there is much movement in microscopes).

But I would always recommend using synthetic greases exclusively (if available), though, for the reasons PeteM pointed out. The research put into the development of synthetic hydrocarbon lubes by companies like Nye has been tremendous, and we might as well take advantage of it.

I have searched for many months and have almost given up my search to find a match to the dark Brown grease zeiss used on the ball bearing section of nosepiece turret assembly the balls are usually stuck to the top piece when you seperate it and well it is very THICK I also have never seen any posts written for rebuilding of nose pieces mostly worm gear linear racks
Well I have bought many types of the so-called helicoid grease and sad to report NON have the properties of the OEM zeiss grease also used on lot of other parts on the standard as well

Cheers