Fixing a Vivitar 28mm with the aperture stuck

Jesito · Expire: 2015-01-07

The lens was sent to me by a friend asking if I could do anything to fix it. It has the diaphragm stuck wide open.

First I opened the backside (mount goes out quite easily) and I was able to move the blades acting against the lever that moves them.

Once the blades exposed, it was pretty clear the problem was an excess of oil on them. But it seemed difficult to access the blades from there, so I took out the front group (that goes out all togheter) and noticed a considerably amount of oil on that side also. With a q-tip, some Isopropylic alcohol and patience, went cleaning the oil from the top side and letting the lens to rest for some hours in the upside-down position (to allow the gravity to do its work on the oil) repeating the process.

Now is working much better but it is still sticky sometimes, so I have to keep cleaning for a while more...

ZoneV · Expire: 2011-12-02

Thank your for this post, seems to be a common problem of the Kiron/Vivitar 28mm f/2.0 lenses.

Minolfan · Joined: 30 Dec 2008 Posts: 3443 Location: Netherlands

Thanks for this thread; I have to do one myself! And a 24mm too Sad

cooltouch · Joined: 15 Jan 2009 Posts: 9109 Location: Houston, Texas

I have two Vivitar Series 1 zooms with the same problem, a 24-48 and a 28-105. I've cleaned the aperture blades on the 24-48 before, but I guess I didn't do a good enough job because the problem is back. All I did was take loose the rear group and clean the blades in situ. As for the 28-105, that lens has been a source of frustration. I thought I would remove the rear group, same as with the 24-48, but I can't get the mount off. One of the levers that controls the full aperture metering is fastened or hooked onto something down deep in the lens and I can't get it freed up, thus the mount won't come off and I can't get to the rest of the lens. And I really don't feel like dismantling the entire lens just to get to the iris blades, so it sits. Confused

As for yours, the best approach is just to be patient. Keep wiping the blades down with alcohol until no trace of oil remains no matter how many times you flick the iris actuator.

guardian · Joined: 18 Mar 2009 Posts: 1747

First, let me say in situ blade cleaning is pretty much my only available option as a practical matter. I have large hands and my vision is not what once it was. So aperture disassembly and re-assembly is not a task I would relish.

That said, now comes the question:

What solvent are you fellows using to clean the blades in situ?????????

I have heard lighter fluid mentioned as an option to address this. I'm not real keen on lighter fluid, but I would use it if it's clearly the best substance to address this problem. Given the high level of lens disassembly which must precede aperture cleaning, at least when you want access to both sides . . well . . it's something you want to get right the first time!! And getting it right means use of the proper solvent!

ETA

At the risk of "overthinking" this:

Perhaps the "proper" solvent varies from lens to lens, depending on the type of helicoid grease used by the lens manufacturer. Sad

cooltouch · Joined: 15 Jan 2009 Posts: 9109 Location: Houston, Texas

As for solvent, if you really don't want to use lighter fluid, aka naphtha, you might try denatured alcohol. Not Isopropyl, which can be 50% water or more. Denatured alcohol is pure ethanol with a bit of methanol mixed in to render it undrinkable. I've used it before for cleaning gunk off of shutter blades and it worked well for this. DOn't see why it wouldn't also work for iris blades.

As for naphtha, it is really pretty safe stuff. It is flammable, but not nearly as dangerously flammable as petrol (gasoline), for example. While I certainly do NOT condone it, I wouldn't be surprised if working with it while smoking a cigarette would not be a cause for undue concern. But why take foolish chances? Anyway, the point being that it is relatively safe to be around.

Naphtha is an excellent solvent for oil and grease, evaporates relatively quickly and leaves no residue. You can buy naphtha here in the States in 1 qt. cans for about $7, which is a LOT cheaper than buying lighter fluid in the squeeze bottles. Oh, and you can buy denatured alcohol in the same size cans for about the same amount of money as well.

Lloydy · Expire: 2022-01-01

Once you have got it stripped down to this stage would one of those cheap ultrasonic cleaners do the job more efficiently ?

http://www.maplin.co.uk/ultra-7000-ultrasonic-cleaner-223108

At these prices it must be worth a try ?

Attila · Expire: 2021-11-18

Many thanks!!

guardian · Joined: 18 Mar 2009 Posts: 1747

sammo · Joined: 04 Jan 2012 Posts: 223 Location: CH and SI

Just a note. If you want to clean oil, don't use alcohol, it does not dissolve oil well. It's better to use warm water and lots of soap. Isopropanol is also much better, but still not a perfect solvent.
Lighter fluid or petroleum ether are the best solvents for degreasing. Well, hexane would be even better, but we don't need high purity chemicals here.

Has anyone ever had any damage done to plastic components or finish on the aperture assembly while cleaning with lighter fluid?

Jesito · Expire: 2015-01-07

I use isopropylic alcohol, bought at a chemioals supply, is 100% water free and evaporates quickly.

peterqd · Expire: 2014-01-04

I've cleaned lots of lenses and cameras with the same small tin of lighter fuel, not to mention cleaning off the sticky mess
left by self-adhesive labels, chewing gum, sticking plasters and so on. One tin goes a long way!

What you do need a lot of is patience. Keep cleaning with a Q-tip and working the blades, and allow time for the fuel to
evaporate completely before you apply more.

guardian · Joined: 18 Mar 2009 Posts: 1747

!Karen · Joined: 20 Jul 2013 Posts: 837 Location: Belgium Baby

I have required this lens today and it has the blades stuck open as well.
Unfortunately your images have disappeared Sad

Mine has minolta sr mount. Should I go from the front or the back?
Suggestions are welcome. Smile

Lloydy · Expire: 2022-01-01

I'm sure you've seen this Karen -

http://photografica.robinparmar.com/vivitar.html

there's a lot of Vivitar 28's.

I've been inside a PK mount Komine and repaired a broken aperture lever and I got in through the back without disturbing any glass, but I really can't remember if you could get at all the mechanism ? I suspect you can.

!Karen · Joined: 20 Jul 2013 Posts: 837 Location: Belgium Baby

Mine is the same as the
M16
In that list
But in sr mount Smile

!Karen · Joined: 20 Jul 2013 Posts: 837 Location: Belgium Baby

The mount came off easily and after that the back group screws off and the blades are exposed. There is a lot of oil on the front of the blades. I need to get in at the front of the lens as I have no idea how to proceed at the back now.
What version was your lens Jesito?
This os a video for the close focus version of this lens:
http://youtu.be/d7GuEyD7nDs

I can't get anything to move at the front of my lens Sad

Edit:
Found this... Going to give it another try
https://www.flickr.com/photos/paulojgomes/2989263302/in/photostream/

Jesito · Expire: 2015-01-07

Lloydy · Expire: 2022-01-01

The front end of the Vivitar is quite simple Karen. Put your rubber gloves on, grip the focus ring, grip the trim ring - which is everything in front of the focus ring - and unscrew it. It should be hand tight. Nothing flies out unexpectedly when the trim ring is removed

Grip the lens block and unscrew that, again it should be hand tight and nothing comes flying out.

This is the body with no glass in front of the aperture. Remove the back glass and you're good for cleaning.