Use of anaerobic glues

[Geoff_H]

Has anyone had experience using Loctite style locking of aircraft bolts?  What type of locking did the Loctite style glues replace? Nylon, metal crimp, wire, split pin?

 

 

[Downunder]

Checkout the Rotax engine manuals. Various loctite grades used.

 

https://www.flyrotax.com/services/technical-documentation.html

 

 

[M61A1]

The aircraft I work on use loctite in a lot of places. I think the only alternative would be to lockwire the fitting.

 

Some parts in high vibration areas us a lock washer and loctite along with a helicoil that has a built in locking medium. I don't like those ones much, as a hamfisted tradie can drag the helicoil out with the bolt.

 

Some hydraulic fittings also use loctite on the B nut.

 

The stuff is very effective. The ones on the hyd fittings for example, will fight you the whole way when you are undoing them and then clean up really easily.

 

 

[facthunter]

Holden used a "one use" nut in the front end where a coating containing a loctite like substance  encapsulated in small beads was used. When tightened, the bead s fractured and released the locking compound in just the right amount and the lock is achieved. Human application could not be relied on to achieve a consistent result on the production line. Clever Eh?Nev

 

 

[spacesailor]

Isuzu Jackaroo were all made using a Loctite glue, no lock washers anywhere.

 

I use it on my propbolts,  as they are torqued every run, New prop working in & compressing the wood.

 

spacesailor 

 

 

[Bruce Tuncks]

I once asked an airforce maintenance guy if the airforce used loctite. He replied that the airforce was held together with the stuff.

 

But is it legal I wonder... how can you tell if it went off? So my suggestion is to check it next day with a gentle spanner. 

 

 

[onetrack]

If liquid anaerobic polymer (which is what Loctite is), is deprived of air, in contact with metal, it sets to a plastic state. Loctite can cope with gaps up to about 0.050" (1.27mm) and it will still set, if it's between metal surfaces.

 

The best part about Loctite is, it's available in a wide range of strengths and designed uses (get a Loctite application/product chart off your distributor, if you can).

 

I've seen the high strength Loctite used on retaining nuts on driveshaft yokes on heavy equipment - and 1 inch drive rattle guns couldn't get the nuts undone, we had to use heat on the nut.

 

https://www.henkel-adhesives.com/au/en/products/industrial-adhesives/anaerobic-adhesives.html

 

 

[Yenn]

Most aircraft have Loctite as a requirement in their maintenance. The strongest grades will allow you to shear off the bolt, unless you use heat. Others can be applied after torquing up and will wick into and hold the thread. I have heard of someone using Loctite, wicking grade (296 I think) to seal a riveted fuel tank, instead of Proseal.

 

 

[Thruster88]

In my farming career I have used Loctite products to repair many things, as they say on the tube (Loctite 660 my personal favourite)  "This product restores a press fit to worn components" good to save a lot of $ in farming but not acceptable for aviation.   

 

 

[Geoff_H]

I have used it extensively in industrial applications.  It works great, but I want to use it in my project.  I am just wondering about the consequences of using in an aircraft.  Would anyone use it as a locking device for wheel retaining nuts?

 

 

[Thruster88]

I have used it extensively in industrial applications.  It works great, but I want to use it in my project.  I am just wondering about the consequences of using in an aircraft.  Would anyone use it as a locking device for wheel retaining nuts?

 

With an Experimental you have alot more freedom. If i thought it would improve the safety my project I would use it but the manufacturer requirements should be followed.  

 

 

[M61A1]

I have used it extensively in industrial applications.  It works great, but I want to use it in my project.  I am just wondering about the consequences of using in an aircraft.  Would anyone use it as a locking device for wheel retaining nuts?

 

I wouldn’t use it for locking wheel retaining nuts, if you are talking about a single centre nut attaching the wheel to the axle because if the bearings seize up or grab for any reason the rotation of the wheel may undo the nut, but I would use it to attach a wheel to a hub with studs if I thought they might vibrate loose.