Problem with Super Glue and Fiber Optics

[RR_Mel]

I was doing a mod to a Athearn HO Observation car when I discovered that one of the 2mm fiber optical runs from LED to lens was clouded and much dimmer than it’s brother.  When I went to remove the fiber it crumbled.

 

That's the first time I've run into anything except Amazing Goop screwing up fiber optics.  Goop melts the fiber.  I've been using super glue for fiber optics to LEDs for 20 years and never had a problem until now.  It only dinged one out of three fibers, all three fibers were off the same roll using the same tube of super glue two years ago????

 

To the best of my knowledge nothing else came in contact with that section of fiber. 

 

Anyone have a similar problem?

 

 

 

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[tstage]

Mel,

I thought fiber optic fibers were silica-based?  How would adhesives affect inert material?  I have very little experience with fiber optics but I would suspect misalignment of one of the fibers as the reason for the poor output.

Tom

[Edit: Okay, after re-reading your post, Mel, your issue is at the junction where the LED and fibers meet.   That would make sense.  Could you use one of the low-fume CAs that doesn't react to polymers?]

[cabman]

Why don't you use canopy glue or Aleen's white glue which won't attack the fiber optic, dries clear, and can be removed with little effort?

[RR_Mel]

Tom

 

The LED to fiber junction looked OK to the eye but the fiber it’s self wasn’t clear like the other two.  The thing that really surprised me was when it broke in pieces when I went to remove it.

 

I replaced all three fibers in the car and the other two looked fine and didn’t crumble when I removed them, they were still flexible.

 

I worked with fiber optics for about 15 years before I retired and I’ve always used the same procedure as I was taught for splicing fiber cables.  This is the first time I’ve experienced this problem.

 

I ask a model railroad friend about the problem and he said something about having some cloudy experience with super glue lately.  He was wondering if maybe they have changed the formula a bit.

 

It just caught me off guard.     

 

 

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[tstage]

Sure sounds like something changed in the material, Mel.  In the past did you use the regular CA, or the low-fume CA?

Tom

[rrebell]

Anything is possible. I asume you used a plastic type as they are more flexable and much cheaper. I could have been heat or over exposure to uv rays which could have happened at the factory but not shown up as a defect at the time, just a guess.

[RR_Mel]

I have two identical observation cars done identical and the other car is OK.  So out of six 1¾” x 2mm fibers only one failed.

 

I store my fiber optical cable in manila envelopes in a closet so I don’t see how they could have been exposed to anything externally.

 

Still can’t figure out why it crumbled.  It broke like glass into about a dozen pieces.  The other five were flexible.  

 

 

I changed the backup lights to stovepipe LEDs and eliminated those fibers in both cars.

 

 

 

 

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[rrinker]

 COuld it be that the joint was less than sealed on this one and left fumes from OTHER CA joints to access the fiber, whereas in the past the joints were rather sealed up so th efumes couldn't get to the fiber? Ir maybe the outer jacket was nicked and fumes attached from th side not the cut face where it glued to the LED.

 I've seen elsewhere that Faller X-pert cement is the thing to use for joining fiber to LEDs since it dries optically clear - I have some but haven't actually done anything of the sort yet to see how well it works.

                      --Randy

 

[RR_Mel]

I guess anything is possible.  Early on I painted the fiber but because very little light comes outside the strands I haven’t done that in several years unless it the light was viewable to the eye.

 

CA isn’t the best adhesive for fiber optics but it’s always worked good enough for my model railroad lighting.

 

Since I found the bad fiber I’ve checked a lot of my fibers and that one is apparently the only with the problem.  It’s been two years since I installed that fiber and who knows what happened during the install process, could have fallen into contact with any number of fluids on my “clean” workbench.  I’ve never been one to keep a clean workbench.  Normally I almost have to look for it.

 

 

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[DigitalGriffin]

tstage

Mel,

I thought fiber optic fibers were silica-based?  

 

 

There's plastic and glass based.  The plastic is cheaper and has a sharper bend radius (less rigid).  But the glass transmits better and less suseptable to internal refraction errors leading to a better bandwidth.

[gmpullman]

I have occasionally had the problem you describe, Mel. I'm sure everyone has their preference for cement. I have used Aleen's but it isn't very strong. Lately I've been using G-S Hypo Cement with good results:

https://gssupplies.com/gs-hypo-cement/

Also, whenever possible, I use a sleeve of heat shrink tubing over the LED/light-pipe bundle for alignment and strength. Black if I have it otherwise clear.

I believe that, for the most part, when we buy some of these parts and components, this stuff is either surplus stock or material that has not met certain specs and is sold off at much reduced prices. Especially true for electronic components. I noticed a lot of the fiber optic strands I bought in bluk assortments were out of round or varied quite a bit in diameter along its length. 

Some good info at this site:

https://thefiberopticstore.com/faqs/

 

Good Luck, Ed

[zstripe]

Mel,

I mentioned this to you before.......I see Ed has already mentioned it. But I also use the G S Hypo Jeweler's cement for quite a few models and yr's. especially window glazing and it works fantastic for a strong bond and does stick to paint. It does have a longer curing time, but drys crystal clear unlike CA adhesives.

Take Care! 

Frank

 

[RR_Mel]

Thanks guys, all very good input.

 

Early on in my 50 year career in Two-Way Radio Communications I worked for a Motorola MSS (Motorola Service Shop) or Motorola, at one time it was common knowledge that the semiconductor plant in Arizona ran as high as 97% reject on some solid state components so you are very correct Ed.  The Motorola Bat Wings went on the ones that passed specs, never heard what happened to the ones that didn’t meet specs.

 

I bought most of my fiber optic cable from China, not necessarily for price but availability.  It wasn’t easy to find some sizes State side.  Most of my fiber is 4 or more years old.  The bad piece could have been bad from the supplier on the front end.

 

As for super glue many years ago I switched from the hobby ACs to Loctite because my LHS closed.  Loctite holds many of the patents on AC so I figured that was my best choice and it’s readily available from any hardware store.

 

After doing some research on AC and discovering that shelf life on an unopened bottle was one year and after it is opened shelf life is one month I switched to Harbor Freight ten packs.  I really liked (and still like) the small tube with the pointy nozzle, much easier to use on small stuff.  I can’t tell any difference between super glues anyway.  At the end of a month I toss the tube I’ve been using and go to a new unopened tube with a fresh nozzle for the next month.

 

 

I’m not bad mouthing any product it’s I just find the small tubes easier to work with for my hobby stuff.  I also use their gel in the small tubes, it comes in handy because it doesn’t run and I get less on my fingers.

 

 

By the way I tried the bacon soda thing with superglue and that makes a fabulous filler.  A buddy has been trying to get me to try it for years.  I needed a small hole filled so I filled the hole with bacon soda and added some super glue, in about a minute I had a super hard filler that was easily workable with my #11 blade and sandpaper.

 

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

[rrebell]

$ stores sell Pacer superglue, same as the good stuff but the front brand is different but the small print says Pacer.

[Metro Red Line]

Three words: Elmer's Clear Glue. Less than $3 per bottle at Michael's.

[dinwitty]

maybe Walthers goo is safe? There is also liquid black tape. I usually don't want a hard connection if I have to remove it for some reason.