[Richie]

This question mainly comes from a slow day at work.
Last weekend  I started getting my bike ready for spring (Which seems to only be here by the calendar in the northeast US) and started having flashbacks of conversations I'd had with an old room mate.
He was a Harley guy and never used any kind of thread locker stuff (Or a torque wrench for that matter).
He always just made a point of keeping up with maintenance and generally checking that nothing is loose....er...I think.
I on the other hand, like the stuff.
You?

[zimmemr]

This question mainly comes from a slow day at work.
Last weekend  I started getting my bike ready for spring (Which seems to only be here by the calendar in the northeast US) and started having flashbacks of conversations I'd had with an old room mate.
He was a Harley guy and never used any kind of thread locker stuff (Or a torque wrench for that matter).
He always just made a point of keeping up with maintenance and generally checking that nothing is loose....er...I think.
I on the other hand, like the stuff.
You?

The shop manual will tell you where and what grade of thread locker to use. If the factory suggests using it, consider that handy information.

Same thing with the torque wrench. For sure you can get away without using one, most guys that make their living turning wrenches have figured that out. But the good ones know when to use it.

[axman88]

I use Loctite when there's reason to believe that an old school lock washer won't do the job.  There's very little of it on my RE, but I generally add a lockwasher whenever I disassemble any bolt, even under a Nylock nut.  Nylocks get lazy after a few assembly cycles, and my tendency to use Anti-sieze probably isn't helping the plastic.

The Blue is nice, because it's strong enough to stay put, but weak enough to remove the fastener without damage.  Red sometimes requires torching loose.  I've sheered quite a few screws that were secured with Red Loctite.  They use Red here in my employer's assembly area.  There's always much cursing when the plant manager wants things reworked for whatever reason.

I have the idea in my head that Red and possibly Blue Loctite may stress crack certain types of plastic, but I could be wrong about this.  I avoid using petroleum based products, like lubricating oil, around plastic.

[Guaire]

Vibra-TITE has worked for me. It's removable and I can clean it out of threads easily.

[Karl Fenn]

Well sometimes where loctite is specifically specified it does in fact pay to use it, but if to just protect threads from corrosion you can use clear nail varnish, it stops and water getting into the threads and stops corrosion you can undo without any special tools, also works holding small screws, of course loctite is not goop, but rather a scientific formular for certain type of engineering applications, if the manual stipulates its use you should use. But no need to use it everywhere very bad idea.

[zimmemr]

I use Loctite when there's reason to believe that an old school lock washer won't do the job.  There's very little of it on my RE, but I generally add a lockwasher whenever I disassemble any bolt, even under a Nylock nut.  Nylocks get lazy after a few assembly cycles, and my tendency to use Anti-sieze probably isn't helping the plastic.

The Blue is nice, because it's strong enough to stay put, but weak enough to remove the fastener without damage.  Red sometimes requires torching loose.  I've sheered quite a few screws that were secured with Red Loctite.  They use Red here in my employer's assembly area.  There's always much cursing when the plant manager wants things reworked for whatever reason.

I have the idea in my head that Red and possibly Blue Loctite may stress crack certain types of plastic, but I could be wrong about this.  I avoid using petroleum based products, like lubricating oil, around plastic.

Axman: you obviously know what you're talking about so this is just to add a little something to the discussion and in no way critical of anything you posted. Besides it's cold as hell here today and I've got nothing to do while I'm waiting for the paint to dry on a honey-do project.

Before retirement I worked for Connecticut Light and Power as a garage foreman working mostly on bucket trucks, diggers and derricks. One of things we discovered there was that in some cases lock washers would actually cause bolts to loosen under certain conditions. The theory was that the lock washer reduced surface contact area and when combined with fretting would reduce it's spring tension allowing the fastener to loosen. In many instances we found that replacing the lock washers with a hardened flat washer worked better. Provided the fastener was properly torqued and a thread locker used as required.

I also tend to use anti-seize on many fasteners, but doing so obviously reduces the friction between the threads and makes it easy to over torque the fastener. So it's important to remember to reduce the applied torque by 10% anytime anti-seize is used, I'm sure you knew that but some readers may not.

As to Loctite stressing plastic, I've never considered it, but it makes sense that as the Loctite hardens and expands slightly it could create issues. And I agree using petroleum based products around any plastic never seemed like a good idea.

Lastly, I don't know why I remember this but I've read that the lifecycle of a plastic locknut is 15 cycles, provided it hasn't been over heated.

[axman88]

Axman: you obviously know what you're talking about so this is just to add a little something to the discussion and in no way critical of anything you posted.

One of things we discovered there was that in some cases lock washers would actually cause bolts to loosen under certain conditions. The theory was that the lock washer reduced surface contact area and when combined with fretting would reduce it's spring tension allowing the fastener to loosen.

I also tend to use anti-seize on many fasteners, but doing so obviously reduces the friction between the threads and makes it easy to over torque the fastener.

As to Loctite stressing plastic, I've never considered it, but it makes sense that as the Loctite hardens and expands slightly it could create issues. And I agree using petroleum based products around any plastic never seemed like a good idea.

Thanks for saying that, but it's probably more accurate to say that I "think" I know stuff, but find out all the time that I don't.   I find that I learn a lot, by making dubious statements (not intentionally) and being corrected.

That item about the lock washers make sense.  One thing is for sure, my RE C5 is a reliable tester of fastener security.  More than one has gone MIA, the worst offender so far, being the nut preventing the rear brake drum from spinning.  It spun, the brake locked up, there was much cursing.

The anti-sieze has become SOP with me.  I grew up in Cleveland, OH, and Chicago is almost as bad a rust breeding environment.  I hate the suspense of trying to remove rusty bolts on the old beaters I have driven all my life.  Will it loosen?  Will it shear?  Will my socket crack or my 1/2" extension break?  The acetylene torch and Kroil gun are my constant companions.  I remember hearing somebody say, many many years ago, ... " I never grease wheel studs, the rust helps hold the lug nuts on!".  I didn't buy that nonsense, even as a 15 year old.  This stuff is my pal:  https://www.amazon.com/Permatex-80078-Anti-Seize-Lubricant-Bottle/dp/B000FW7VGE/

 Stress cracking in plastic isn't exactly mechanical stress, and it isn't entirely chemical attack.  It's a combination of both factors, and every time I've seen it in action it has totally blind sided me.  Remove the stress and the chemical won't attack, remove the chemical and the stress is manageable, but together, big trouble.  Here's a write up describing the phenomenon in some detail.  https://www.plasticstoday.com/materials-analyst-part-22stress-cracking-how-avoid-silent-killer-part-1

I had time to do more research.  I was correct about Red Loctite 271 and Blue Loctite 242.  Both carry the mfg's warning "Not for use on plastic parts, particularly thermoplastic materials where stress cracking of
the plastic could result".   https://dm.henkel-dam.com/is/content/henkel/TDS-209741-US-Loctite-Threadlocker-Red-271-Carded-Tube-0.20-fl-oz-2018-04-09pdf
https://dm.henkel-dam.com/is/content/henkel/TDS-209728-US-Loctite-Threadlocker-Blue-242-Carded-Tube-0.20-fl-oz-2018-04-09pdf

I suppose it's probably the Methyl methacrylate causing the problem?  I see that the stuff also contain Saccharin, no idea why, and some other ingredients that we need to be warned about.  https://ypsswhdoal-a0d0758e9.dispatcher.hana.ondemand.com/SAP_GATEWAY/odata/SAP/YPSSWH_DOO_SRV/SafetyDataSheetSet(Appid='YPSSW_SDSUA_EXT',Matnr='209741',Laiso='EN',Rvlid='US',Dmskey='')/$value

The fact that regular Loctite is incompatible with plastic is probably why they invented Loctite 425, which is expressly compatible.
https://www.all-spec.com/Product/135461-30769

[REpozer]

It’s my experience with RE , that you need to occasionally hit all fasteners with spanners/ wrenches and Loctite all parts/ spares that you can’t afford to loose .

[zimmemr]

Thanks for saying that, but it's probably more accurate to say that I "think" I know stuff, but find out all the time that I don't.   I find that I learn a lot, by making dubious statements (not intentionally) and being corrected.

That item about the lock washers make sense.  One thing is for sure, my RE C5 is a reliable tester of fastener security.  More than one has gone MIA, the worst offender so far, being the nut preventing the rear brake drum from spinning.  It spun, the brake locked up, there was much cursing.

The anti-sieze has become SOP with me.  I grew up in Cleveland, OH, and Chicago is almost as bad a rust breeding environment.  I hate the suspense of trying to remove rusty bolts on the old beaters I have driven all my life.  Will it loosen?  Will it shear?  Will my socket crack or my 1/2" extension break?  The acetylene torch and Kroil gun are my constant companions.  I remember hearing somebody say, many many years ago, ... " I never grease wheel studs, the rust helps hold the lug nuts on!".  I didn't buy that nonsense, even as a 15 year old.  This stuff is my pal:  https://www.amazon.com/Permatex-80078-Anti-Seize-Lubricant-Bottle/dp/B000FW7VGE/

 Stress cracking in plastic isn't exactly mechanical stress, and it isn't entirely chemical attack.  It's a combination of both factors, and every time I've seen it in action it has totally blind sided me.  Remove the stress and the chemical won't attack, remove the chemical and the stress is manageable, but together, big trouble.  Here's a write up describing the phenomenon in some detail.  https://www.plasticstoday.com/materials-analyst-part-22stress-cracking-how-avoid-silent-killer-part-1

I had time to do more research.  I was correct about Red Loctite 271 and Blue Loctite 242.  Both carry the mfg's warning "Not for use on plastic parts, particularly thermoplastic materials where stress cracking of
the plastic could result".   https://dm.henkel-dam.com/is/content/henkel/TDS-209741-US-Loctite-Threadlocker-Red-271-Carded-Tube-0.20-fl-oz-2018-04-09pdf
https://dm.henkel-dam.com/is/content/henkel/TDS-209728-US-Loctite-Threadlocker-Blue-242-Carded-Tube-0.20-fl-oz-2018-04-09pdf

I suppose it's probably the Methyl methacrylate causing the problem?  I see that the stuff also contain Saccharin, no idea why, and some other ingredients that we need to be warned about.  https://ypsswhdoal-a0d0758e9.dispatcher.hana.ondemand.com/SAP_GATEWAY/odata/SAP/YPSSWH_DOO_SRV/SafetyDataSheetSet(Appid='YPSSW_SDSUA_EXT',Matnr='209741',Laiso='EN',Rvlid='US',Dmskey='')/$value

The fact that regular Loctite is incompatible with plastic is probably why they invented Loctite 425, which is expressly compatible.
https://www.all-spec.com/Product/135461-30769

As usual there's good info here. I forget that this side of the page has a lot of Classic riders, I tend to think in terms or Himalayans or Interceptors which aren't as vibratory. You're also the first guy I've seen here to mention Kroil, in the truck/heavy equipment business we swear by the stuff. It saved more heartaches than Dear Abby in our shop.

As far as anti-seize on the lug nuts, I had a DOT inspector read me the riot act for using it on one of our line trucks. He claimed I'd over torqued the wheels using it. I explained that I'd reduced the torque from 450 to 400 ft lbs when I installed them but the SOB still made me pull all the nuts, clean the studs and nuts and retorque everything. After that I made sure to do a better job cleaning off the excess before I sent the trucks back on the road. 

[AzCal Retred]

Years back we had taken in a used touring bike with a curved but flat windscreen on the fairing. The greasy desert grasshoppers had left a Windex-resistant baked on spot, so my partner in crime reached for the Krylon De-Greaser. A quick spritz and the grasshopper guts were no more, just sparkling clarity. In a few seconds a foggy, opaque spot appears. My buddy figures it's just residue drying and out comes the Windex again. Much rubbing & wiping ensues. The spot is visibly getting larger, we're thinking "Damn, we've got sand on the rags". The center of the opaque spot is getting fissured. Over the next few minutes we watched the entire windscreen turn to plastic diamonds and fall out, like in some low-budget sci-fi movie. A trip to the plexiglass folks, some jigsaw & sander work, a couple hours spent carefully drilling said plexiglass with a steel bit, and voila, a like new windscreen. Lucky it was flat. 

[Guaire]

To Loctite or not to Loctite.
  That was the question. What's going on here?

[GlennF]

You can always drill all the nots and bolts and put in split pins

[zimmemr]

You can always drill all the nots and bolts and put in split pins

Safety wire! Make it look like the race bike it is.

[AzCal Retred]

Guaire @ #10:  Unanticipated chemical interactions with plastics, that was the tie in. Test on a separate piece if unsure of the outcome.

[axman88]

To Loctite or not to Loctite.
  That was the question. What's going on here?

Actually the title of the thread is "Loctite and other such goop".

Threads always seem to drift, but pointing out that the common Loctite products shouldn't be used on plastic, and why, seems pretty relevant.  Anti-sieze, being essentially the polar opposite of Loctite, arguably qualifies as "other such".

I try to bring threads back on topic by posting more info that is ON topic, and not just complaining about the chatter.