any tips on un-loctiting lens retaining rings?

duncsuss · 08-28-2009, 01:54 PM

I've got a lens with a small amount of fungus on the rear surface of the second element from the front.

With a lens spanner wrench I got the front bezel off and the front element out. Now I'm faced with a second retaining bezel/ring that is not cooperating at all -- I think the assembly workers must have used Loctite on it.

I read that heat can break the bond -- but can't think of a safe way to apply heat to it.

Anyone have experience in this operation? Would it work if I touch a soldering iron to the bezel and work my way around the ring? (Or would the Loctite at the start of the circle lock again as soon as I move the iron tip away from it?)

Thanks for any and all help --

Duncan

rormeister · 08-28-2009, 02:02 PM

We're a Loctite distributor. If it's Red you'll need to get it upwards of 100 degrees farenheit before it'll break loose (with effort). Blue usually will work free unwillingly w/o heat. No chemicals should be used.

**pacerr** · 08-28-2009, 02:02 PM

It would be helpful to know WHICH lens is involved, but if you believe heat's the answer try a hairdryer with due precautions.

H2

duncsuss · 08-28-2009, 02:13 PM

Originally posted by pacerr

It would be helpful to know WHICH lens is involved, but if you believe heat's the answer try a hairdryer with due precautions.

H2

It's the Pentax-A 35-105mm 1:3.5.

I guess my questions should have been:

- is heat the answer?
---- if so, how best to apply, and what precautions would you recommend?
---- if not, what would the answer be?

Thanks

duncsuss · 08-28-2009, 02:16 PM

Originally posted by rormeister

We're a Loctite distributor. If it's Red you'll need to get it upwards of 100 degrees farenheit before it'll break loose (with effort). Blue usually will work free unwillingly w/o heat. No chemicals should be used.

Thanks -- I have no idea if it really is Loctite, let alone what colour it might be. All I know is I've been unable to shift it ... the front bezel was tight but on the 3rd or 4th attempt came free. I've tried this second bezel maybe a dozen times now, nada.

little laker · 08-28-2009, 03:04 PM

Duncan,
Often your moms old tricks work best. The amount of heat you would require would almost certainly damage something, however tapping the lens in the right place might just free it up. Like mom did to free up Jar Lids.

Without seeing what your dealing with I can only give general instructions, so you may have to modify them to work in your situation... but Since I wouldn't want to tap on the glass it's self, or on any threads I'd try looking for a short piece of pipe, or a socket (as in socket tool set) it fits neatly into without the threads or glass touching anything.
Find one for the top as well, however you don't want them touching in the middle

Gran out the old hammer, Brass works best. Then give the top socket a couple of good solid taps.

**alfa75ts** · 08-28-2009, 03:06 PM

Normal lens glue (most commonly green but sometimes red or blue) can be softened with acetone. Dip a cotton bud in acetone and apply to glued area, allow to seep in, remove cotton bud and wait approx 2 minutes.

Caveat: use on plastic lenses at your own risk!

Edit: This information comes from a Vivitar repair manual.

seacapt · 08-28-2009, 08:03 PM

I could be wrong but I have been told tha there is a light seal ring just behind the front element in an A 35-105 that is somewhat complcated to remove. That is a very nice lens and might be worth your while to have it professionally cleaned.

duncsuss · 08-29-2009, 08:54 AM

Originally posted by seacapt

I could be wrong but I have been told tha there is a light seal ring just behind the front element in an A 35-105 that is somewhat complcated to remove. That is a very nice lens and might be worth your while to have it professionally cleaned.

Ah, thanks for the heads-up ... perhaps it's a good thing that I haven't been able to unscrew it then!

Any recommendations for how to find a reputable cleaner?

seacapt · 08-29-2009, 10:34 AM

If you don't have a good camera doctor locally there are quite a few reputable repair facillities on line.
Eric Hendrickson is highly regarded here on this forum and has been working with Pentax product for decades. You might shoot him an e-mail and tell him what you got. He will give you a no BS answer and an estimate for repair. He has done work for me in the past and I've been pleased.
His adress: Pentaxrepairs@aol.com

duncsuss · 08-29-2009, 11:03 AM

thanks -- I've sent email to Eric

08-28-2009, 01:54 PM	#1
duncsuss Senior Member Join Date: Aug 2008 Location: Massachusetts Posts: 239	any tips on un-loctiting lens retaining rings? I've got a lens with a small amount of fungus on the rear surface of the second element from the front. With a lens spanner wrench I got the front bezel off and the front element out. Now I'm faced with a second retaining bezel/ring that is not cooperating at all -- I think the assembly workers must have used Loctite on it. I read that heat can break the bond -- but can't think of a safe way to apply heat to it. Anyone have experience in this operation? Would it work if I touch a soldering iron to the bezel and work my way around the ring? (Or would the Loctite at the start of the circle lock again as soon as I move the iron tip away from it?) Thanks for any and all help -- Duncan

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08-28-2009, 02:02 PM	#2
rormeister Veteran Member Join Date: Dec 2007 Location: USA Photos: Gallery Posts: 626	We're a Loctite distributor. If it's Red you'll need to get it upwards of 100 degrees farenheit before it'll break loose (with effort). Blue usually will work free unwillingly w/o heat. No chemicals should be used.

08-28-2009, 02:02 PM	#3
pacerr Loyal Site Supporter Join Date: Jan 2008 Location: Paris, TN Photos: Gallery \| Albums Posts: 3,349	It would be helpful to know WHICH lens is involved, but if you believe heat's the answer try a hairdryer with due precautions. H2

08-28-2009, 02:13 PM	#4
duncsuss Senior Member Join Date: Aug 2008 Location: Massachusetts Posts: 239 Original Poster	Originally posted by pacerr It would be helpful to know WHICH lens is involved, but if you believe heat's the answer try a hairdryer with due precautions. H2 It's the Pentax-A 35-105mm 1:3.5. I guess my questions should have been: - is heat the answer? ---- if so, how best to apply, and what precautions would you recommend? ---- if not, what would the answer be? Thanks

08-28-2009, 02:16 PM	#5
duncsuss Senior Member Join Date: Aug 2008 Location: Massachusetts Posts: 239 Original Poster	Originally posted by rormeister We're a Loctite distributor. If it's Red you'll need to get it upwards of 100 degrees farenheit before it'll break loose (with effort). Blue usually will work free unwillingly w/o heat. No chemicals should be used. Thanks -- I have no idea if it really is Loctite, let alone what colour it might be. All I know is I've been unable to shift it ... the front bezel was tight but on the 3rd or 4th attempt came free. I've tried this second bezel maybe a dozen times now, nada.

08-28-2009, 03:04 PM	#6
little laker Veteran Member Join Date: Sep 2006 Photos: Gallery Posts: 5,697	Duncan, Often your moms old tricks work best. The amount of heat you would require would almost certainly damage something, however tapping the lens in the right place might just free it up. Like mom did to free up Jar Lids. Without seeing what your dealing with I can only give general instructions, so you may have to modify them to work in your situation... but Since I wouldn't want to tap on the glass it's self, or on any threads I'd try looking for a short piece of pipe, or a socket (as in socket tool set) it fits neatly into without the threads or glass touching anything. Find one for the top as well, however you don't want them touching in the middle Gran out the old hammer, Brass works best. Then give the top socket a couple of good solid taps.

08-28-2009, 03:06 PM	#7
alfa75ts Loyal Site Supporter Join Date: Jun 2009 Location: Melbourne Australia Photos: Albums Posts: 1,356	Normal lens glue (most commonly green but sometimes red or blue) can be softened with acetone. Dip a cotton bud in acetone and apply to glued area, allow to seep in, remove cotton bud and wait approx 2 minutes. Caveat: use on plastic lenses at your own risk! Edit: This information comes from a Vivitar repair manual.

08-28-2009, 08:03 PM	#8
seacapt Veteran Member Join Date: Nov 2008 Location: North Carolina , USA Photos: Gallery Posts: 2,271	I could be wrong but I have been told tha there is a light seal ring just behind the front element in an A 35-105 that is somewhat complcated to remove. That is a very nice lens and might be worth your while to have it professionally cleaned.

08-29-2009, 08:54 AM	#9
duncsuss Senior Member Join Date: Aug 2008 Location: Massachusetts Posts: 239 Original Poster	Originally posted by seacapt I could be wrong but I have been told tha there is a light seal ring just behind the front element in an A 35-105 that is somewhat complcated to remove. That is a very nice lens and might be worth your while to have it professionally cleaned. Ah, thanks for the heads-up ... perhaps it's a good thing that I haven't been able to unscrew it then! Any recommendations for how to find a reputable cleaner?

08-29-2009, 10:34 AM	#10
seacapt Veteran Member Join Date: Nov 2008 Location: North Carolina , USA Photos: Gallery Posts: 2,271	If you don't have a good camera doctor locally there are quite a few reputable repair facillities on line. Eric Hendrickson is highly regarded here on this forum and has been working with Pentax product for decades. You might shoot him an e-mail and tell him what you got. He will give you a no BS answer and an estimate for repair. He has done work for me in the past and I've been pleased. His adress: Pentaxrepairs@aol.com

08-29-2009, 11:03 AM	#11
duncsuss Senior Member Join Date: Aug 2008 Location: Massachusetts Posts: 239 Original Poster	thanks -- I've sent email to Eric

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