JB Weld on mounts

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DuctTapedGoat

Active Member
Dec 20, 2010
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Locktite and JB Weld are really the same kind of product in that they can perform the same thread sealing purpose.

Not only that - they are removed with heat. Any 20 dollar heat gun can remove JB Weld and even HiTemp Locktite.
 

DuctTapedGoat

Active Member
Dec 20, 2010
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I like Locktite - when you use it right. Put a drop or two on the bolt threads, let it set overnight and THEN - use your bolt.

I have had success using JB Weld in freezing a freewheeling sprocket, but honestly, where I'd like to use it is in places where there's so much heat it won't hold up.
 

FileStyle

New Member
May 27, 2008
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I use blue loctite on fenders and smaller bolts of the like, I never use it on motor mounts!
if by chance you have used loctite in the motor mount and you break a bolt/stud flush in the hole, it takes alot more to remove the broken part from the motor, where as if you used a good bolt and no locktite and everything is aligned properly you dont need it.
 

NormO

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Jun 15, 2011
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I find there is no substitute for higher grade bolts fine thread, and decent lock nuts. Only ever had to use loctite sleeve retainer to fix a seal on an Echo CLS 5800 Spacing saw. Never use it anywhere else.
 

MarkSumpter

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Nov 27, 2010
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My personal experience is that there is a time and place for the use of thread locking sealants such as Loctite and commercial grade 2 part epoxies that depend on specific conditions including material and conditions under which it is being used.

With that said I have also found that most people are uneducated on the specific applications and uses of most sealers and grab one willy nilly and end up causing themselves lots of poblems. Sometimes the misuse of products can cause serious damage to the assembly or even injury (or worse) to the user from the adhesives failure.

Some things you should know about thread locking adhesives and metal specific epoxies.

Not all thread locking adhesives are the same. Loctite is made in the USA under very demanding quality control and testing conditions there for you get more uniform results using their products over some of the cheaper brands available through discount sources.

Loctite as well as all other thread locking sealants are age and storage sensitive in that if you have a tube that has been laying in your tool box for over a year you will find that it concentrates from age and has a higher degree of thread locking. If the thread locker has frozen while in storage it should not be used as some of its ingredients can have separated and become ineffective. Likewise if it has been exposed to high temperatures for a long time it can cause a concentration of the ingredients resulting in higher degrees of locking. Most of the time I simply buy a new tube of Loctite for a specific job unless I am sure that what I have on hand is fairly new and not been stored in extremes of temperature.

Using the right formula for the right job and using it properly is essential to proper thread locking and removal of parts after assembly. There are 3 formulas of Loctite brand thread adhesive available to the general consumer:

(from Loctite website)
  • Loctite® Threadlocker Green 290™
    Nut and Bolt Locker

    Loctite® Threadlocker Green 290™ is designed for the locking and sealing of threaded fasteners. Due to it's low viscosity and capillary action, the product wicks between engaged threads and eliminates the need to disassemble prior to application. Loctite® Threadlocker Green 290™ cures when confined in the absence of air between close fitting metal surfaces. It prevents loosening from shock and vibration and leakage from shock and vibration and protects threads from rust and corrosion. The product can also be used to fill porosity in welds, casting and powder metal parts. Localized heating and hand tools are needed for disassembly.
  • Loctite® Threadlocker Blue 242®
    Nut and Bolt Locker

    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.
  • Loctite® Threadlocker Red 271™
    Nut and Bolt Locker

    Loctite® Threadlocker Red 271™ is designed for the permanent locking and sealing of threaded fasteners. 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. It is only removable once cured by heating up parts to 500°F (260°C).

A couple of other things to keep in mind when using thread sealants is that they lose their effectiveness to a varying degree when used on parts that are contaminated with grease, oil or gas. Both surface areas should be thoroughly cleaned with a solvent before being sealed. And the finish adhesion of parts is directly related to the surface area being sealed. That is if you coat a set of surface threads over its entire mating surface the adhesion will be greater.

Personally I have found no use for the Red formula of Loktite on these engines and only use a single drop of the Green formula at the base of cleaned cylinder / head studs in the crankcase and allow it to wick into the threads. And only if I have a problem with front and rear mount studs loosening will I use a single thin line (allowed to dry before installation) around the center of the threads with the Blue formula.

Concerning 2 part epoxies.

There are 3 formulas that come to mind:


First off these are each good products when used in the right application. They are not thread sealants or thread restoration compounds and while they say solvent / fuel resistant they are not impervious to degradation when exposed to those compounds.

I will not put my (or my friends and customers) safety or investment in jeopardy by using these products to repair threads, or attach parts. There are far better solutions like welding (either tig or alumi weld) and then redrilling or tapping as needed. I do use JB Weld as a sealer when installing a tapered or threaded pulse port below the jug base or intake not for strength but more to insure there are no air leaks. You can also use these products to repair small cracks and breaks in ferrous and non ferrous metals as long as you remember that it can be affected by heat and fuel and not in a stress critical area.

OK so this is the end of my rant and I hope it is helpful to those new to motorized bicycle riding and small engines, it comes from over 30 years in the small engine industry and seeing people do stupid things and get themselves or others hurt or simply bringing me a machine with 2 inches of JB smeared on it and wanting me to fix it as good as new but "don't worry about the JB Weld fix it works great"... Then I laugh and tell them to find another shop...

*edit* Many years ago I had a commercial customer that had an out of balance diamond blade on a Stihl Concrete saw loosening head bolts and instead of replacing the blade he took every screw out that he could get to and sealed them with the Red formula, I never was able to get that darn saw apart to rebuild it too many bolts either stripped the heads or broke off...
 
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DuctTapedGoat

Active Member
Dec 20, 2010
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Yay Mark - that's awesome.

It's nice to see someone who knows there's a time and place when concerning the application of threadlockers and epoxies.

+1, kudos.
 

2door

Moderator
Staff member
Sep 15, 2008
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Thanks Mark. Now all we have to do is get those die-hards to read and head your rant.
Regarding the two part epoxy issue; I'm a devoted fan of Devcon products when it comes to metalized epoxy products. They aren't cheap, but they work.
Tom
 

MarkSumpter

New Member
Nov 27, 2010
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Ohio
Thanks Mark. Now all we have to do is get those die-hards to read and head your rant.
Regarding the two part epoxy issue; I'm a devoted fan of Devcon products when it comes to metalized epoxy products. They aren't cheap, but they work.
Tom
Thanks Tom I know of Devcon products but have never used them myself. Still even they (I am sure) have limitations that must be understood. And as for getting other to read and follow my suggestions... Aint a gonna happen I bet... LOL...
 

flybytaco

Metal Molding Madman
Oct 17, 2009
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seekonk MASS
gordon jennings uses devcon to fill and regrind ports. I agree that loctite has its place, I would use it on nuts but not the actual studs into the aluminum cases as mentioned before by Filestyle if the bolt breaks flush it will be much harder to remove. A lil off topic but I've been inside the motor of my Ducati and every single tapped hole in the cases has a stainless heli coil from the factory. Thats smart thinking for sure next time i do a personal build i'm gonna helicoil my stud holes for the motor mounts.
 

kevinkrg6

New Member
Jun 3, 2011
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ohio
I had to fill my rear mount with JB weld to make it fit, because it did not mount at the correct angle (70 degrees, which my bike is not....).

It will likely give me trouble down the road, but I am about to do a final mount for my engine.

I think I will just secure the bottom mount as good as possible (considering I rethreaded for 5/16 (AMERICAN!) studs), so that little pressure will be on the back.

I didn't know what else to do. The mount has to be flush, ya know?