Problem With Loc-Tite Blue

[Bobby G]

While I had my fairing split to work on replacing my headlamp bulb and doing some cleaning and general maintenance, I removed my deflectors to clean them real good. I reinstalled them last night using a touch of Loc-Tite Blue on the phillips-head bolts and snugged them up without overtightening. This morning when I replaced the bulb and went to re-assemble the fairing, the deflectors literally fell off their mounts. It appears that the Loc-Tite disintegrated the ABS plastic protrusions that the screws mount into on the inner fairing. It's hard to describe, but the plastic turned to black crumbles. I've never seen anything like it. Has anyone ever experienced this with Loc-Tite Blue? My inner fairing will no longer be able to hold the deflectors, unless I can rig something up. This sucks.

 

The pic shows the right side deflector mounted as of last night.

 

Any suggestions would be appreciated.

[wizard]

I also learned the hard way that most any thread lock and plastic don't mix. I tried it on a bolt that kept backing out in my saddle bag.

[Sylvester]

Never use petroleum or caustic substances on plastic. Totally melts it down. Just as bad as brake fluid.

 

I won't tell you how I know!

 

[Sling]

Check out this site http://plastex.net/ sounds like you are going to have to rebuild the

screw mounts.. Never tried the stuph but I hear it works great

[Wizard765]

plastex is amazing stuff and will rebuild the tab for you including the threads.. Works like a charm.

[kj5ix]

 

Loctite® Threadlocker Blue 242®

 

Nut and Bolt Locker

 

 

• Overview
• Features
• Technical Data
  
• Directions
  

Loctite® Threadlocker Blue 242® is designed for the locking and sealing of threaded fasteners which require normal disassembly with standard hand tools. The product cures when confined in the absence of air between close fitting metal surfaces. It protects threads from rust and corrosion and prevents loosening from shock and vibration. Loctite® Threadlocker Blue 242® is particularly suited for applications on less active substrates such as stainless steel and plated surfaces, where disassembly is required for servicing.

• http://www.loctiteproducts.com/img/products/icons/t_lkr_blue-1.png
  
• http://www.loctiteproducts.com/img/products/icons/t_lkr_blue-2.png
  
• http://www.loctiteproducts.com/img/products/icons/t_lkr_blue-3.png
  

Other Recommended Product Solutions

 

Loctite® Threadlocker Red 271™

Loctite® Epoxy Weld™ Bonding Compound

Loctite® Threadlocker Green 290™

 

 

Recommended For

 

• Use on metal fasteners 1/4" (6 mm) to 3/4" (19 mm) in diameter such as bolts on small engines, swing sets and furniture
  

Not Recommended For

 

• Use in pure oxygen and/or oxygen rich systems and should not be selected as a sealant for chlorine or other strong oxidizing materials
  
• Use on plastic parts, particularly thermoplastic materials where stress cracking of the plastic could result
  

[V7Goose]

I have posted here many times that Loctite must not be used on ABS plastic. In fact, it must be avoided even where the screws just pass through the plastic and into a metal bracket, such as the saddlebag lid mounts. Unfortunately, not everyone has seen those older threads, and some just do not believe it. Last time I posted that, the kind gentleman who I was trying to warn just told me how stupid I was to post the warning. Oh well . . .

 

Best of luck getting that repaired - I do not know how long that stuff will continue to eat into the base plastic and weaken it for any repair.

Goose

[Bobby G]

Wish I'd seen your post on this earlier. Live and learn I guess. I'm still pissed. And for the record, there is no warning on the packaging about this like there is on their web site.

[midnightventure]

I used it once on the screw that held the knob on one of my Delta faucets. It cracked up in pretty short order. I try to avoid getting it close to any plastic anymore.

[Flyinfool]

+1 more, Most threadlockers will destroy most plastics.

 

I would grind off the damaged plastic right away to stop the damage from continuing to spread. Just take some good pics and measurements first so that you know exactly where and how high to rebuild it.

 

If you are concerned with the fasteners backing out of plastic, there are 2 options that I know of.

 

1. Use Loctite #425 which is made for metal or plastic fasteners.

2. Use some RTV on the threads.

 

When referring to Loctite, it is not safe to just say the color, There are only five colors to use on forty or so different grades and strengths of Loctite. Also different brands use different colors for different things.

[Monty]

Another one learns the hard way...

http://www.venturerider.org/forum/showthread.php?t=51404

[ragtop69gs]

Check out this site http://plastex.net/ sounds like you are going to have to rebuild the

screw mounts.. Never tried the stuph but I hear it works great

 

I never used plastex but I have used http://www.plast-aid.com/ which is probably the same type product. I have used it to cast and repair parts, also used it to repair a leaky pvc pipe on my hot tub worked like a charm in both instances. It can be drilled, tapped and painted. It fixed the broken tabs on my lower fairing.

[skydoc_17]

Having worked with thread lockers in the Aero Space Industry for 38 years I learned a long time ago that Loc-Tite and plastic don't mix. There are even thread lockers that are so caustic that they will dissolve aluminum! I have to be real careful when using fasteners and chemical thread lockers on the air planes I work on.

Over the years, I have MANY times used a single wrap of the white Teflon plumbers tape to tighten up a loose fitting screw in a plastic thread. Now don't go crazy and put ten wraps of the tape on the screw, or you will split the plastic female thread, but a single wrap will snug up that screw just fine. PLUS every time you remove the screw, just re wrap the screw and you are good to go. The tape is easy to find, is cheap and there is NO chemical interaction between the screw and the plastic.

I am sorry that you got this info late, but someone else might find it useful.

Earl

[Bobby G]

I never used plastex but I have used http://www.plast-aid.com/ which is probably the same type product. I have used it to cast and repair parts, also used it to repair a leaky pvc pipe on my hot tub worked like a charm in both instances. It can be drilled, tapped and painted. It fixed the broken tabs on my lower fairing.

 

Thanks Jay. I just ordered some Plastex to do the repair on the inner fairing protrusions. Hopefully it will also fix the tabs on the deflectors, or I'll have to replace them.

[IdahoRon]

Here's a trick I have used for locking bolts and screws, when locktite is not desirable.

I keep a small tube of RTV silicon in my tool box for such instances. Just put a little silicon

on the threads. It will lock the threads, fasteners are removable, it withstands vibration well, and it will also seal pipe threads.

[ragtop69gs]

Thanks Jay. I just ordered some Plastex to do the repair on the inner fairing protrusions. Hopefully it will also fix the tabs on the deflectors, or I'll have to replace them.

 

When you do the repairs, it will adhere better if you sand off the paint down to the raw plastic. Sand repaired area to a smooth finish then repaint. Have everything prepped and ready before you mix the plastaid.

 

Good luck.