Lens Lube---J8.Suitable grease.

[SCOTFORTHLAD]

I just received from Russia a very clean, unmarked and optically good, chrome J8 ,which has quite stiff focussing.Equipped with the data sheets from Kim Coxon's Site,I am going to have a go at a lube job.Can anyone with more experience recommend a suitable grease which I could easily find here in the UK.
Thanks,
Brian.

 

[Peter_Jones]

I wouldn't use a synthetic "silicon" grease - that stuff "weeps" everywhere.

I would hazard a guess at Lithium grease giving good results, from cycle shops etc. (feel free to correct if anyone has had negative experience of Lithium grease)

 

[Mauro]

I agree on a cycle grease: I lubed my J8 with a motorcycle chain lube (BTW, I proudly own a Royal Enfield Bullet!), as it is a high temperature resistant therefore it should not weep when you use your lens in hot summer days.
My J8 focusing is smoother now, and I have not experienced any problem .
Hope this helps.

 

[Peter_Jones]

Mauro - Royal Enfields are great bikes, always good to hear the steady beat of a traditional single. I ride a Meriden Triumph. Wonder how many RFFers ride classic bikes ?

 

[laptoprob]

... or classic cars?

 

[Mauro]

What a great surprise, dear Peter!
I love classic bikes and cars, above all from Great Britain: I remember my first summer in Hastings in 1981, "Triumph frog eyes" - Jensen cars - Norton and Triumph bikes were parked outside pubs.
I will add a picture of my Royal Enfield (I have called it "King George VI") to the W/NW Motorcycles forum: it would be nice to meet someday, discussing about bikes and cameras with a glass of good beer (I still remember Triple Diamond brand)

 

[ZorkiKat]

"Super-Lube" (USA Syncolon) works. Does not "weep" and is quite heat resistant.

The grease's viscosity is important with many FSU lenses. Part of the helicoid's
accuracy depends on the thickness of the grease. Some "stiffness" is actually appreciated to prevent the threads from slipping. A lubricant which is too thin or slick can make the movement inaccurate and cause focusing errors similar to rangefinder backlash.

Automotive axle grease seems to be very close to the lubricant originally used.

 

[Spyderman]

I use white lithium grease - just as Rich Pinchbeck shows somewhere on Kiev Survival Site... Does not "weep" which is important, and is quite thick. An exception in Jupiter-9 which has 4 helicoids, so I use a thinner synthetic grease intended for bike suspension forks.

 

[dee]

Lambretta model d 1957 - slow and steady wins the race - at least around corners !
well it had to be a ''dee '' didn't it !
Oh and there is an updated model being trialled with 10 '' wheels , suspension that works, and a matched, rebuilt higher compression engine top speed 60 mph ... will bring it bang up to date ... 1959 ?

But thrashed mine 25 miles each way over 3 years to college , 10 years old in 1967 ... until the poor thing blew it's top - hole in the piston , just under the fuel tank / seat / me ...and saw off a rocker on a 175 bantam , 'cos he just could not throw it around the street corners as i did - so escaped intact in notorious redhill - free pas from the ruling motorbike clan ...

seem to have wandered of topic ...

who needs Zorkis for an exciting time ?

 

[SCOTFORTHLAD]

Thanks friends---I will visit the cycle shops here by the weekend.

I was into 4 wheels myself,especially as Dad didn't trust me with a Lambretta or a Vespa.
Quite fancied one of those Bubble Cars though,an Isetta,or one of thos Messchersmits,which I think used an aircraft cockpit as the 'cabin'.Really cool if you had been brought up on post WW2 stories and legends.

Ended up with an Austin A35 Van conversion,then sold it to raise the deposit on the house.Probably the best decision I ever made,as I still live in it!

Pethaps all this explains my FSU 'obsessions'.

Brian.

 

[Peter_Jones]

😀 Owned a Vespa for a while - great fun but terrifying brakes and steering. Was reg'd as a "50" but with a much larger engine in, went like the proverbial off a shovel ! (relatively speaking). The wheels could easily be swallowed up by the potholes in Blackburn (The Beatles underestimated the number of holes) 😱 leading to disturbing handling.

Mauro - I'll try to get a RF photo of the "Bonnie" posted when time allows. There's many a good beer to sample 😀

 

[Blank288]

I mostly use ball-bearing grease, which I apply very modestly. Have had good results with it.

Erik

 

[Xmas]

Brian (& Brian)

A vacuum pump grease may be ideal as you want both a zero creep and zero vapour pressure grease. You dont want the grease escaping from the heliciod or out gassing on the optics, as fog.

I use a Tandy/Radio Shack PTFE 'grease' when I need it thick and a PTFE liquid same source when I need it thin as both are thermally stable very cold or very hot. I dont mind the Ru heliciod rattle, I prefer no stickyness in focus.

Not seen Brian's bouncing around, effect myself, I'll have to try it.

Noel

 

[SCOTFORTHLAD]

Erik,Brian and Noel,
Thanks for the tips---more grist to the mill,for myself and others who might follow this.

Cheers,
Brian.

 

[Peter_Jones]

Good luck with the re-lube , should be well worth the effort, I really like my J8 - I need to clean & lube an Industar 61, so I will see how well my lithium grease works (can't make it any stiffer).

 

[SCOTFORTHLAD]

Thanks Peter,I'll let you know how I get on.

Who knows perhaps one day I will point the J8 at Lancaster Castle!

BTW if you need a guide on sorting out the I61 look at Kim Coxon's site,he has all the details there.

www.pentax-manuals.com-repairs

Brian.

 

[SCOTFORTHLAD]

It's done!
Finally picked up a tube of lithium grease from the cycle shop today,and successfully sorted out the stiff focussing on the J8 this evening.😀

The lens now focusses really smoothly, but is not too slick ---much satisfaction for a mechanical dunce like me.

The original lubricant reminded me of congealed cooking oil after being used in a fryer!

Thanks everyone for the help,

Brian.