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Hai
Tinkerer
Username: Hai
Post Number: 7
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, November 27, 2007 - 07:42 am: | 
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Hi,
What grease or lubricant should I use for the focusing helical in my lenses?
Thanks!
Hai |
Steve_s
Tinkerer
Username: Steve_s
Post Number: 90
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 29, 2007 - 12:59 am: |
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A lot of people recommend synthetic bicycle grease (no specific brand), so this is probably your best bet. I haven't tried any yet, but intend to soon.
What I'm actually using myself at present is Castrol BNS, which is a Bentone based high-temperature bearing grease. I'm pretty sure my tin is at least 30 years past its "best before" date, but it shows absolutely no sign of oil separation and seems to do the job. I don't know if this would be available in the US, and in any case, Castrol stopped making their own grease about 15 years ago (at least for the UK market), so I cannot be sure the current BNS would be identical.
A while back I tried some Nyogel 795A which some people seem to like, but found it made the focus MUCH too stiff, certainly for an SLR, where you need to be able to rock the focus either side of the focus point. Next I tried Kluber Catenera KSB 8 which I have also seen recommended online. This was better, but still too stiff for my liking, though I might give it another try next time I have a helical with a fairly coarse thread. |
Glenn
Tinkerer
Username: Glenn
Post Number: 230
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 29, 2007 - 06:47 pm: |
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The Nyogel Damping products work very well, but you have to choose the grade required by experiment. I also found that the 795A was far too heavy - if one packed the whole helix with grease - just placing 3 or 4 dabs around the helix will give a good movement on some lenses.
However, the lighter grades will produce the original factory feel, if you do a bit of experimenting with them. The added bonus is that they do not separate out or migrate, a problem with many off the shelf products. |
Steve_s
Tinkerer
Username: Steve_s
Post Number: 91
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 30, 2007 - 01:33 pm: |
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When I tried the Nyogel, I certainly did pack the helical. With a multistart thread I always want to be sure that all the threads have plenty of grease - dry aluminium threads have a nasty tendency to "pick-up" which can be very bad news indeed!
Which grade of Nyogel would you try, Glenn? There are 779 and 774L grades described as "very light", and 774VL "ultra light", as well as some more exotic-looking products. Too much experimentation could get rather expensive! I found a source of Nye products here in the UK, which worked out a bit cheaper than Microtools, Germany - but not much. The 795A is described as a "light" damping grease, and just in case it turned out to be a bit too light I also invested in a tub of 773A which is described as "medium". Needless to say, this has remained unopened! They are not completely immune to oil separation - at least not according to the FAQ on the Nye web-site.
I must admit, I have never been completely convinced that a damping grease is best for this job, rather than a normal lubricating grease. |
Markamra
Tinkerer
Username: Markamra
Post Number: 4
Registered: 03-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 06, 2007 - 04:33 pm: |
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If it's not too late. I go with the first suggestion of synthetic bicycle grease. I can't be much use with a brand name because I'm in the UK and use Halfords (National UK retailer) own brand. It's a red coloured general purpose silicone cycle grease and I find it gives a nice "feel". Works great on fine threaded compact lenses but is a bit light on the bigger SLR helicoils, needs more packing. Being silicone it remains consistent across a wide temperature range. |
Glenn
Tinkerer
Username: Glenn
Post Number: 240
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 08, 2007 - 06:58 am: |
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Steve,
Like you I found a/the UK supplier of Nye products - but only after I had increased Microtools, European profit margins! I have recently moved house, so I cannot easily lay my hands on the Nye products/ reference numbers. A few years back I got my hands on some nice early Russian L39 lenses, these had been stripped and cleaned - but not reassembled. At the time I was repacking my lenses with a silicone grease, originally supplied by Paragon Plastics, to lubricate the o-rings on their ranges of push-fit drainage pipes. I had this sitting on a shelf for years, it never separates and does a good job on smaller diameter lenses and all 35mm slr lenses. I was also rebuilding a 180/2.8 Sonnar, the Paragon grease did not have enough 'body' to hold the helix components apart - due to the weight and diameter of the inner barrel.
So, seduced by Microtools web site I purchased the two tubes of 700 series that were then advertised - a light and medium grade. I found that the medium was far too heavy, even on the !80mm, and the light, whilst OK on the 180mm was far too heavy for the Russian and my Canon lenses etc.
Foolishly, after some thought I brought the kit of Nye 800 series products from Microtools. This was a cheaper version of the kit now on the website, only difference - package came in cardboard box and greases were in tubs. You now get a fancy plastic case and products packed in syringes, all for $100 - a $40 increase!
I still found that the medium to heavy ranges were not usable, even on large heavy lenses. However they are quite good for larger microscope slides!!
I do not think I made the application of the 3/4 dabs of the heavier products clear. The ideal is to fill all the 'lead ins' ie a strip of approx 1/2" completely round the top circumference, and the same for the bottom 'lead outs' of the helix. The mating surfaces of the helix are thus held apart by the grease film, the un-greased portions never touchings. I was given this info by lens restorer whose work I respect. It certainly is in keeping with the theory of lubrication and works on my Jena 120 and 180 lenses.
However like you, I like to fully pack the helix, perhaps this is why we find the 'recommended' products give unsatisfactory results. My £3.00 pot of Paragon silicone has performed flawlessly over the years, on all but a few medium format lenses.
I suggest a sensible answer to the question of which/what grease, is to continue using a product that you have experience with, and you know works. Any person working on his first lens will have to see what is available in his locality, looking for similar products to those that have been recommended on this forum. |
Commando303
Tinkerer
Username: Commando303
Post Number: 14
Registered: 10-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 15, 2007 - 11:54 pm: |
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I've recently acquired some molybdenum disulfide ("moly") grease, and I just love it. Petroleum jelly ("Vaseline") or silicone lubricant — the two are very similar — work well enough and are easily found, but they can be a little tough to use in lower temperatures and they always leave you with that little fear that, if you've used too much and it gets too warm, the stuff will leak from its place. Maybe a stick of Land O' Lakes butter... mmm... |
Steve_roberts
Tinkerer
Username: Steve_roberts
Post Number: 6
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, December 19, 2007 - 08:49 am: |
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I've successfully used Castrolease LM on several lenses. It's a GP grease, cheap in the UK and readily obtainable. Being specified for automotive wheelbearings (where you don't want it to run away if it gets hot) it shouldn't be a problem in lenses. I don't know whether it might get a bit claggy at low temps, but that's not often an issue in the UK.
Steve |
Steve_s
Tinkerer
Username: Steve_s
Post Number: 93
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 20, 2007 - 04:56 am: |
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As Glenn suggests, if it works for you, then keep using it, Steve, but a word of warning: I gave up using Castrol LM in wheel-bearings many, many years ago, because it suffered VERY badly from oil separation. This is bad news for the brakes in ancient vehicles using felt seals, and probably, for the diaphragm in camera lenses!
I found that with most general purpose automotive Lithium greases you can see free oil running on the surface if you take the lid off in the store. I would check yours, before your next lens, particularly if you've had it a year or two. |
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