Sticky substance on outside of lens barrel

**Sam_I_am** · 04-20-2020, 02:11 PM

I was wondering if anyone has run across this before. I would assume the lens is not worth repairing but wondered what caused it. I thought maybe something was spilled on it but the camera bag, camera, and other accessories are free from the stickiness. The outside of the barrel is covered with something very sticky that I cannot remove. I tried soap and water, then tested a spot with IA, then did the same with fingernail polish remover.(at this point I figured I could not make it worse). The other thing that is troubling is what appears to be a felt seal being pulled out from inside the lens due to the sticky substance. Really sad because the optics are crystal clear.

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stevebrot · 04-20-2020, 03:53 PM

Something bad has happened to that lens. The yuck on the lower barrel is degraded guide seal for the zoom. Whether the sticky comes from the degraded seal or from solvent attack of the paint is hard to say. Does it clean off with naptha (lighter fluid)?

Steve

**Sam_I_am** · 04-20-2020, 04:32 PM

Have not tried that. Just a sec..

---------- Post added 04-20-20 at 04:45 PM ----------

OK, while I was cleaning it with lighter fluid it felt like it was removing the sticky. I was really excited because my towel was not turning black, Then when the lighter fluid evaporated, it was sticky again.

**AstroDave** · 04-20-2020, 06:38 PM

Originally posted by stevebrot

Does it clean off with naptha (lighter fluid)?

Originally posted by Sam_I_am

OK, while I was cleaning it with lighter fluid it felt like it was removing the sticky. I was really excited because my towel was not turning black, Then when the lighter fluid evaporated, it was sticky again.

I'm not sure it's much different from these solvents, but maybe have a go with some Goof Off: https://www.homedepot.com/p/Goof-Off-6-oz-Professional-Strength-Multi-Surfac...G661/206726072

Make sure you get the stuff in the little can with the flip-up lid

This stuff is amazing, but it does tend to wreak havoc on some plastics!

Last edited by AstroDave; 04-20-2020 at 09:10 PM.

photoptimist · 04-20-2020, 07:33 PM

Sometimes clear packing tape can be used to lift sticky materials off of surfaces. It all depends on the relative adhesive strength of the lens-to-goop, goop-to-tape-adhesive, and tape-adhesive-to-tape-backing strengths. Try sticking a bit of tape on the sticky area and then lifting the tape slowly.

**ramseybuckeye** · 04-20-2020, 07:51 PM

If it is a Sigma lens it is probably the zen barrel coating that was used for a while. I have a lens like that, mine is a 50/2.8 macro that really performs well. I tried several things like alcohol and more. I forget what I used that seemed to work and I put the lens away. the next time I picked the lens up the barrel and focus ring was petty much welded together. I ended up cutting the ring off, the lens is still usable, but an ugly lens now. I don't know what these lenses were like new and why the the coating, but they apparently strangely deteriorate with time

Astro-Baby · 04-20-2020, 11:29 PM

It coukd just be the seal thats the problem. Some foams and synthetic rubbers decompose. The Olympus E10 had a rubber grip that would go this way and the only fix was removing the grip. It would contaminate surfaces near to it very readily and was like hot tar to remove.....it got on everything.

If you could strip the lens and get the barrel apart you may find a wash down with very hot soapy water will remove it.

It may be the actual paint. I had a telescope part years ago where the paint started to decay and it went like wet paint, always sticky and oozing black goo. The super hot water, soap and a stiff brush cleaned off the paint easily enough but it then had to be reenammelled.

**jlstrawman** · 04-21-2020, 08:05 AM

It might be something similar to this:

How to clean sticky radios | The SWLing Post

Not a Number · 04-21-2020, 08:57 AM

Be aware that lighter fluid can act like a mild polish so when you are rubbing down matte or semi-matte surfaces they may become gloss or semi-gloss.

Urethane foams from the 80's tend to turn either to powder or a nasty sticky goo. I've never found anything that effectively dissolved it other than soap and water and a lot of "elbow grease". I'd try the suggested pulling off with sticky tape, the stickier the better or scraping as much off as possible with a nylon pot scraper or wood tongue depressor.

You might try MEK but be careful and where it goes or gets on as it may react with some plastics and rubber.

**AstroDave** · 04-21-2020, 11:17 AM - **1 Like**

Originally posted by Not a Number

You might try MEK but be careful and where it goes or gets on as it may react with some plastics and rubber.

Yes, Indeed! Be VERY careful with this stuff. I had a supervisor (a summer job in a paint chemistry lab) who got some paint on his tie (probably nylon or orlon - something synthetic). He put the tie in a can of MEK, put it on the paint shaker, and when he opened the can, the tie was GONE! Dissolved by the MEK!

mkgd1 · 04-21-2020, 11:42 AM

You might try WD40, it's less aggressive and less toxic than MEK but does remove sticky residue from many surfaces.

**MossyRocks** · 04-21-2020, 12:50 PM

Originally posted by ramseybuckeye

If it is a Sigma lens it is probably the zen barrel coating that was used for a while. I have a lens like that, mine is a 50/2.8 macro that really performs well.

I have the Sigma 300mm f/4 APO Macro with the awful Zen coating. It was a little sitcky when I got it so I wiped it down a couple times a day over the course of a week with some 90% isopropyl alcohol and the problem has gone away. That was probably close to 2 years ago now so it appears to have worked there, but it wasn't really bad when I got the lens.

**Alex645** · 04-21-2020, 01:48 PM

Originally posted by Sam_I_am

I was wondering if anyone has run across this before. I would assume the lens is not worth repairing but wondered what caused it.

I see this all too frequently, especially here in Hawaii because of....mosquitoes. It is usually caused by someone that has applied DEET bug repellent onto their hands or I've seen folks just put a huge cloud of bug spray and the droplets fall everywhere. There is a bad a reaction on most polymers with DEET that causes destruction of the contact surface at the molecular level.

I've also seen this happen to homes or apartment buildings that were tented for termites. Although a gas is usually used and the pesticide is supposed to be safe for anything other than wet food products, I've seen it attack various polymers.

With a lot of elbow grease and Goo Gone, I've been able to reduce 95% of the stickiness, but never completely. Sometimes after using the Goo Gone and then wiping it clean, Armor All can help restore the damaged plastic.

And for those of us dealing with mosquitoes and photography, I can recommend Picaridin as an alternative to DEET. It isn't quite as bug proof, but it won't damage polymers like DEET. Good luck Sam.

**Sam_I_am** · 04-21-2020, 02:20 PM - **1 Like**

Well guys...
First, it's a Quantaray.
WD40....did not work

Skipped the MEK because the fingernail polish remover is acetone base and it did not work, just turned the rag black as did the alcohol.

Two or three different tapes did not lift the sticky.

No goof off handy.

I tried scrubbing the surface with an old toothbrush. First with Dawn, then with 409, and finally with a little purple power. All had the same results, which was taking the surface paint off.

Side note - the rubber grip material and plastic end caps ARE NOT STICKY, just the barrel paint.

So I am leaning towards the same problem Astro-Baby had with his telescope part, and that it is the finish.

---------- Post added 04-21-20 at 02:30 PM ----------

Oops, missed your comment Alex645 while I was posting. Interesting thing about the DEET.

With the DEET damage, did ALL of the surfaces get sticky? Only the painted surfaces appear to be affected on this lens.

**Alex645** · 04-21-2020, 07:57 PM

Originally posted by Sam_I_am

Side note - the rubber grip material and plastic end caps ARE NOT STICKY, just the barrel paint.

With the DEET damage, did ALL of the surfaces get sticky? Only the painted surfaces appear to be affected on this lens.

No, with DEET I've only seen it affect certain plastic, resins, or rubber-like materials...not paint...so now I doubt DEET is the cause.

But the fix? I would tape closed where the metal barrel enters the focus or zoom collar and tape over the rear lens mount.
Then I would get some steel wool, wet sand paper of various grit, and a paint solvent. Wear gloves and see if you can strip the paint off the barrel. Use any solvent sparingly so as to not allow it to drip internally. Paint strippers are always messy, but with patience, you'd hopefully remove the sticky paint.

I have also read where sticky paint on metal can be fixed by a couple coats of primer. I wouldn't do that, however, unless it was a last resort.

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04-20-2020, 03:53 PM	#2
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Something bad has happened to that lens. The yuck on the lower barrel is degraded guide seal for the zoom. Whether the sticky comes from the degraded seal or from solvent attack of the paint is hard to say. Does it clean off with naptha (lighter fluid)? Steve

04-20-2020, 04:32 PM	#3
Sam_I_am Site Supporter Join Date: Mar 2020 Location: Toledo, OR Posts: 851 Original Poster	Have not tried that. Just a sec.. ---------- Post added 04-20-20 at 04:45 PM ---------- OK, while I was cleaning it with lighter fluid it felt like it was removing the sticky. I was really excited because my towel was not turning black, Then when the lighter fluid evaporated, it was sticky again.

04-20-2020, 06:38 PM	#4
AstroDave Loyal Site Supporter Join Date: May 2007 Location: Flagstaff, Arizona Posts: 1,648	Originally posted by stevebrot Does it clean off with naptha (lighter fluid)? Originally posted by Sam_I_am OK, while I was cleaning it with lighter fluid it felt like it was removing the sticky. I was really excited because my towel was not turning black, Then when the lighter fluid evaporated, it was sticky again. I'm not sure it's much different from these solvents, but maybe have a go with some Goof Off: https://www.homedepot.com/p/Goof-Off-6-oz-Professional-Strength-Multi-Surfac...G661/206726072 Make sure you get the stuff in the little can with the flip-up lid This stuff is amazing, but it does tend to wreak havoc on some plastics! Last edited by AstroDave; 04-20-2020 at 09:10 PM.

04-20-2020, 07:33 PM	#5
photoptimist Pentaxian Join Date: Jul 2016 Photos: Albums Posts: 5,128	Sometimes clear packing tape can be used to lift sticky materials off of surfaces. It all depends on the relative adhesive strength of the lens-to-goop, goop-to-tape-adhesive, and tape-adhesive-to-tape-backing strengths. Try sticking a bit of tape on the sticky area and then lifting the tape slowly.

04-20-2020, 07:51 PM	#6
ramseybuckeye Site Supporter Join Date: Apr 2009 Location: Hampstead, NC Photos: Gallery Posts: 17,295	If it is a Sigma lens it is probably the zen barrel coating that was used for a while. I have a lens like that, mine is a 50/2.8 macro that really performs well. I tried several things like alcohol and more. I forget what I used that seemed to work and I put the lens away. the next time I picked the lens up the barrel and focus ring was petty much welded together. I ended up cutting the ring off, the lens is still usable, but an ugly lens now. I don't know what these lenses were like new and why the the coating, but they apparently strangely deteriorate with time

04-20-2020, 11:29 PM	#7
Astro-Baby Veteran Member Join Date: Nov 2018 Location: Reigate, Surrey Posts: 764	It coukd just be the seal thats the problem. Some foams and synthetic rubbers decompose. The Olympus E10 had a rubber grip that would go this way and the only fix was removing the grip. It would contaminate surfaces near to it very readily and was like hot tar to remove.....it got on everything. If you could strip the lens and get the barrel apart you may find a wash down with very hot soapy water will remove it. It may be the actual paint. I had a telescope part years ago where the paint started to decay and it went like wet paint, always sticky and oozing black goo. The super hot water, soap and a stiff brush cleaned off the paint easily enough but it then had to be reenammelled.

04-21-2020, 08:05 AM	#8
jlstrawman Site Supporter Join Date: Feb 2010 Location: Midwest US Photos: Gallery Posts: 1,058	It might be something similar to this: How to clean sticky radios \| The SWLing Post

04-21-2020, 08:57 AM	#9
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	Be aware that lighter fluid can act like a mild polish so when you are rubbing down matte or semi-matte surfaces they may become gloss or semi-gloss. Urethane foams from the 80's tend to turn either to powder or a nasty sticky goo. I've never found anything that effectively dissolved it other than soap and water and a lot of "elbow grease". I'd try the suggested pulling off with sticky tape, the stickier the better or scraping as much off as possible with a nylon pot scraper or wood tongue depressor. You might try MEK but be careful and where it goes or gets on as it may react with some plastics and rubber.

04-21-2020, 11:17 AM - 1 Like	#10
AstroDave Loyal Site Supporter Join Date: May 2007 Location: Flagstaff, Arizona Posts: 1,648	Originally posted by Not a Number You might try MEK but be careful and where it goes or gets on as it may react with some plastics and rubber. Yes, Indeed! Be VERY careful with this stuff. I had a supervisor (a summer job in a paint chemistry lab) who got some paint on his tie (probably nylon or orlon - something synthetic). He put the tie in a can of MEK, put it on the paint shaker, and when he opened the can, the tie was GONE! Dissolved by the MEK!

04-21-2020, 11:42 AM	#11
mkgd1 Pentaxian Join Date: Dec 2019 Location: Mohave county Arizona Photos: Albums Posts: 1,076	You might try WD40, it's less aggressive and less toxic than MEK but does remove sticky residue from many surfaces.

04-21-2020, 12:50 PM	#12
MossyRocks Loyal Site Supporter Join Date: Nov 2017 Location: Minnesota Photos: Gallery \| Albums Posts: 2,982	Originally posted by ramseybuckeye If it is a Sigma lens it is probably the zen barrel coating that was used for a while. I have a lens like that, mine is a 50/2.8 macro that really performs well. I have the Sigma 300mm f/4 APO Macro with the awful Zen coating. It was a little sitcky when I got it so I wiped it down a couple times a day over the course of a week with some 90% isopropyl alcohol and the problem has gone away. That was probably close to 2 years ago now so it appears to have worked there, but it wasn't really bad when I got the lens.

04-21-2020, 01:48 PM	#13
Alex645 Site Supporter Join Date: May 2015 Location: Kaneohe, HI Photos: Albums Posts: 3,527	Originally posted by Sam_I_am I was wondering if anyone has run across this before. I would assume the lens is not worth repairing but wondered what caused it. I see this all too frequently, especially here in Hawaii because of....mosquitoes. It is usually caused by someone that has applied DEET bug repellent onto their hands or I've seen folks just put a huge cloud of bug spray and the droplets fall everywhere. There is a bad a reaction on most polymers with DEET that causes destruction of the contact surface at the molecular level. I've also seen this happen to homes or apartment buildings that were tented for termites. Although a gas is usually used and the pesticide is supposed to be safe for anything other than wet food products, I've seen it attack various polymers. With a lot of elbow grease and Goo Gone, I've been able to reduce 95% of the stickiness, but never completely. Sometimes after using the Goo Gone and then wiping it clean, Armor All can help restore the damaged plastic. And for those of us dealing with mosquitoes and photography, I can recommend Picaridin as an alternative to DEET. It isn't quite as bug proof, but it won't damage polymers like DEET. Good luck Sam.

04-21-2020, 02:20 PM - 1 Like	#14
Sam_I_am Site Supporter Join Date: Mar 2020 Location: Toledo, OR Posts: 851 Original Poster	Well guys... First, it's a Quantaray. WD40....did not work Skipped the MEK because the fingernail polish remover is acetone base and it did not work, just turned the rag black as did the alcohol. Two or three different tapes did not lift the sticky. No goof off handy. I tried scrubbing the surface with an old toothbrush. First with Dawn, then with 409, and finally with a little purple power. All had the same results, which was taking the surface paint off. Side note - the rubber grip material and plastic end caps ARE NOT STICKY, just the barrel paint. So I am leaning towards the same problem Astro-Baby had with his telescope part, and that it is the finish. ---------- Post added 04-21-20 at 02:30 PM ---------- Oops, missed your comment Alex645 while I was posting. Interesting thing about the DEET. With the DEET damage, did ALL of the surfaces get sticky? Only the painted surfaces appear to be affected on this lens.

04-21-2020, 07:57 PM	#15
Alex645 Site Supporter Join Date: May 2015 Location: Kaneohe, HI Photos: Albums Posts: 3,527	Originally posted by Sam_I_am Side note - the rubber grip material and plastic end caps ARE NOT STICKY, just the barrel paint. With the DEET damage, did ALL of the surfaces get sticky? Only the painted surfaces appear to be affected on this lens. No, with DEET I've only seen it affect certain plastic, resins, or rubber-like materials...not paint...so now I doubt DEET is the cause. But the fix? I would tape closed where the metal barrel enters the focus or zoom collar and tape over the rear lens mount. Then I would get some steel wool, wet sand paper of various grit, and a paint solvent. Wear gloves and see if you can strip the paint off the barrel. Use any solvent sparingly so as to not allow it to drip internally. Paint strippers are always messy, but with patience, you'd hopefully remove the sticky paint. I have also read where sticky paint on metal can be fixed by a couple coats of primer. I wouldn't do that, however, unless it was a last resort.