Help Removing Glued-on TC

[longrunner]

Thanks for the suggestions everyone!

Ok, 10 hours in a ziplock back, in the freezer, just resulted in having really cold hands. I spent about 30 mins twisting the thing JUST as it came out of the freezer and the bag, but it didn't budge. I have pretty strong hands (I'm the designated jar-opener) but that's all I'm using -- I don't have a vise setup (yet).

As it came up in the above post, the glue on the lens is at least 8 years old.

Below is a picture of the lens and what I understand to be the catch to release the TC. I'm pushing in the direction of that white arrow (which does move), and twisting clockwise : nothing moves except perhaps the apeture ring when my hands get in the way. Counterclockwise also does not result in anything productive moving. I'm applying pressure while twisting for perhaps a 30-seconds to a minute, steadily increasing pressure, until the veins in my head feel like they're going to pop. Then I give it a little more... nothing moves!

Tonight, and this weekend, I'll be doing the cold/hot technique. I'm considering ways to hold this thing as it comes out of the oven, and how to twist it as I'm heating it with a hot-air gun...

Thanks much!

 

[longrunner]

Good question. No idea. My dad had this lens, and he really liked making things stay in place -- with epoxy, usually. He's dead now, so we'll have to break out the Ouija board to get the answer.

Why in the hell is the TC glued onto the 180mm??
--
Mike L.

 

[Will64]

Joe,

You seem to have a good deal of intelligence about many different things - chemistry, optics, etc. I always enjoy reading your answers, because they are very enlightening and in-depth. I'm just curious, what type of engineering do you do?

--Will
------

 

[Brutus2600]

Am I the only one that thinks putting this fantastic lens in the oven is a bad idea? As for the freezer...

I work with computers, and we get the occasional hard drive crash that has a file somebody absolutely needs off it. The hard-drive-in-freezer trick has worked a couple times, but you really only have one shot for this. The reason being bringing the HD down to freezing temperatures, then introducing it to a room of 75 degrees causes condensation on the platters inside the hard drive.

So anyway, what I'm getting at is, would you not be creating condensation inside the lens, leading to a really messed up lens? I just really think the best idea for this (originally expensive) lens would be to send it into Nikon and see how much it would cost for them to fix it. I mean, even $200 would be a steal for that lens.

 

[Will64]

Tonight, and this weekend, I'll be doing the cold/hot technique.
I'm considering ways to hold this thing as it comes out of the
oven, and how to twist it as I'm heating it with a hot-air gun...

Get some rubberized cooking gloves, like silicon or similar. They will resist the heat and allow you to get a good grip on the lens. And don't bang it as has been suggested, regardless of which end you are tapping on. A lot of the vibration will just be transfered through the TC to the lens. Would you feel any better if you dropped it on a concrete floor and it landed on the TC instead of the front end? I think not.

I hope you get it apart, because you will have a very nice lens, and it will mean all the more to you since it was your dad's.

--Will
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[key5000]

As I know, the white mark with a blue errow point at it is a converter pin lock to your camera, that pin have nothing to do with the remove of out of your lens.

For a hot and cold methods, for me, I would not recommend to use it due to the cold moiseture will get into your lens or the hot might damage the circuit board inside the lens and it will affect the quality of the lens.

What I would use to remove the lens is:

Buy a very fine small hand saw (from Home Depot or local store) and try to cut the glue (saw it on the side of the converter NOT the lens). Just saw a little dip and go all around the converter then use the exactor knife to take off the glue and try to twist the converter off the lens. If it still not coming out then saw a little bit dpper and repeat an above steps. Make sure to marek where is the pins of the lens and REMEMBER NOT TO SAW THE GOLD PINS OF THE LENS.

I think if you spend about an hour or two with that step then you can make it.

DO IT VERY GENTLE AND PAY ATTENTION TO THE SAW CUT.

good luck

--
Regard,
KEY

 

[Mig]

As I stated above - you need to use a filter remover wrench or bottle opener wrench that uses rubber strips. You need two - one for TC one for lens. PUt them in the proper opposing direction and excert pressure - slow and constant.

You can find these at NAPA, Wal-Mart and places like that. This should not harm the lens b/c they are rubber. You have more power b/c of leverage. Should be able to get a set for ten bucks and retire from your job as bottle/jar opener once the items are used on the lens.

 

[Seiji]

I hope after getting the TC off, you don't discover why the person glued it on there to begin with.
--
http://www.pbase.com/seijikamiya/seiji_kamiya

 

[pdw]

Acetone will soften some epoxies and, IIRC, won't touch lens coatings. Holding the combo pointing up at 45 degrees (TC down) and dripping in a small amount of acetone with a tooth pick might work.

 

[Question_Man]

While I agree that dust might be an issue. If you taped a plastic bag over the lens and up to where is joined the TC, that would eliminate any dust from coming in on the outside.

The TC would protect the rear until it was off

I would just start slicing is as close to the lens as you fee comfortable with a cut off wheel on a die grinder.

The problem is that the shear strength of the screws holding the rear lens mount is weaker than the epoxy holding the TC to it. If you twist too hard, than the screws will fail. If you can get down to the actually TC mount. Then you can cut it and push both halfs without putting any stress on the lens. To cut the actually female part of the TC you will need a milling machine and the dust would be very minimal. You also would not use coolant.

 

[rwfernandes]

I do not have this lens, but I think that I've read it has no rear glass element. (sorry for the weird grammar, english is not my first language). So the aperture blades are exposed to air. I would worry about metal filings falling in there.

--
--
Visit my (small) gallery: http://members.home.nl/rw.fernandes/index.html

 

[monte12345]

To make it possible to break loose the locktighted mounting screws for the rear flange in order to "AI modify" a lens. It's been 100% successful without any damage to any lens and I have done about 8 lenses in the last 20 years. However, being a car nut I have an infared thermometer and make sure to not exceed 140 degrees F. Cars that have been parked in the sun on a hot summer day commonly hit 140 degrees and Nikon knows that sometimes their equipment will be subjected to being stored in a very hot car. That is why I feel the oven technique is perfectly safe for a one time attempt, I just wouldn't make a habit of it.

Strange as it sounds, it's also a method the some camera repairmen would resort to with a camera that had been dropped in fresh water. There advice was usually to put the camera in a bucket of distilled water and bring it to them submerged. That prevented oxygen from corroding any steel parts and made it possible to "bake" the camera dry quickly enough so that rust didn't have time to form. Of course this was in the days of all mechanical cameras and any camera subjected to this kind of torture required a total CLA after drying out. My Uncle went through this with a Kodak Retina IIIc (never zoom with your feet by backing up on a pier) and that camera worked perfectly for many years after it's "bath".

 

[Will64]

And I've been reading for years about cleaning floppy drives and circuit boards by running them through your dishwasher (no soap). I've never been brave enough to try it though.

--Will
------

 

[longrunner]

It's off! Like many conjoined twins, the TC and the lens have been successfully separated!

Thanks everyone, for the suggestions!

What didn't work:

• freezing the lens for 10 hours, then twisting
• clamps -- it was just on too tight

WHAT DID WORK:

950 degrees of heat-gun applied around the lens for a couple minutes. I tried to twist it off after a couple minutes at 750 degrees: didn't budge. After a couple more minutes at 950 degrees, the TC twisted off as simple as twisting the knob on a radio. It came right off in my hand, I simply could not believe I was holding the lens in one hand and the TC in the other.

Below are the pix. Sorry they're a little blurry, I was (and still am) very excited, that I simply snapped away. The TC was still warm 10 minutes after it had been removed.

Now I'm going to clean up the lens and remove the epoxy left on there.

Thanks for the help; I'd still be looking at "F--" if it weren't for everyone's help. I'm just -really- glad I didn't have to go the chemical nor hack-saw route (though I did look at saws for a while at Home Depot)

The last picture, you can see how the TC plastic started to melt.



FREE AT LAST!



My shaking had holding my new lens



Melted plastic TC -- Oh well!

 

[longrunner]

Thanks, Phil!

A $40 heat gun did the trick. It took a lot higher heat (at least, the setting on the gun, I didn't measure the air) than 158F -- I was at 950F, then the TC just peeled right off.

I'm now cleaning off the epoxy on the lens and it's coming right off (someone else mentioned it would just peel right off - and it does).

Thanks for the suggestion. I was worried about my fingers, but cheap runners gloves (cotton) was all I wore, and it was fine.

All adhesives loose strength with temperature!
Epoxy starts to soften above 70 degrees Centigrade ( 158 deg F).

Try to apply local heat to the TC and you should be able to get it
off.
Hot water??, Heat Gun?? Other??
Don't burn your fingers!

Epoxy rests can be removed mechanically, preferably while soft.
Careful with the gold contacts for camera body control.

Check for eventual heat damage to the lens first!

I wont accept responsibility for any damage to the lens, but I have
fairly extensive experience mucking around with epoxy glues.

P.S. After 20 odd years away from SLR shooting I'm making my way
back with a D70 and via extensive lurking to catch up on the new
game.

Dizzy from all the info here. ; )

--
Phil_L

 

[travellerben]

Congratulations! Must have taken some nerve and/or desparation to use that much heat. Hope the 180 is ok. It's a fine lens.

Many have wondered why your father did that. My guess is that the combo was slightly loose, he commonly used epoxy on things, he was willing to always have the tc on the lens. so he simply tightened the connection with epoxy.
--
Ben

 

[travellerben]

desparation = desperation
--
Ben

 

[longrunner]

Hi,

The lens works great. I can't believe it. My dog is going to go blind with the flashes I've been popping, testing the lens. Seems perfect. I cleaned off all the epoxy from the lens, and mounted it on my camera -- no problems.

Yeah, my father was a bit kooky on some things. The thing is, this lens-TC combo worked with every camera he owned. It's just my D70s that it doesn't work with it. He took bird pictures in lots of light, so I guess the combo worked well for him... And he did love his epoxy...

Congratulations! Must have taken some nerve and/or desparation to
use that much heat. Hope the 180 is ok. It's a fine lens.

Many have wondered why your father did that. My guess is that the
combo was slightly loose, he commonly used epoxy on things, he was
willing to always have the tc on the lens. so he simply tightened
the connection with epoxy.
--
Ben

 

[Uncle Wally]

Wow. This has to be the best thread I've read in quite some time.
I love the diverse expertise on this forum.

I also own a Nikon 180 EDIf and have been considering a tele for it, but you have effective scared me away from that decision. I can't imagine getting one stuck on my precious and tack sharp 180. Enjoy the lens and please share some pictures with us.

Now i do have a 98' Ford Taurus with a loose driver side mirror. What was the name of that Epoxy again?

 

[Adria]

What a great thread. Glad you got it free!
--
http://www.pbase.com/adriainpdx