Loctite Inspection?

[mdcondro]

Is there a way or a device to inspect for anaerobic loctite application on a screw threads after installation?

The assemblies I'm involved in building require loctite on every screw, followed by thorough cleaning which removes any traces of excess loctite. The method I have set up to assure that loctite has been applied is making the assembly operators record loctite cure start time on each part's mandatory history log. This is merely a "warm-fuzzy" rather than a mistake-proof method.

 

[MikeHalloran]

The referenced APM page touts preapplied patches per MIL-DTL-18240F _and_ strips _and_ pellets, all of which I'm guessing APM subs out.

I personally prefer the fourth alternative, microencapsulated liquid threadlocker, because patches, strips, and pellets all require so much initial torque that hand assembly is impossible.



Mike Halloran
Pembroke Pines, FL, USA

 

[btrueblood]

Syd, yes I would be in hot water. Lucky my current job has no HR dept.

I agree with Mike and Cory, the pre-applied Loctite is lovely stuff. But there are knock-off products for sale that look like, but don't quite work like, the name-brand stuff.

Nylon patches are a one-time use, IMO - the second time used, the patch has taken a "preset" and no longer locks as tightly as the first time.

Of course, the OP could always use option #5 and lock-wire all fasteners...<running for cover>

 

[KENAT]

CoryPad, what I'm actually saying is that we investigated pre applied thread adhesives and could never get them to be financially appealing. Order quantities were too high or the price for smaller quantities too high. There may have been technical issues too, I can't remember now it was a while ago.

As to the Nylon Patches, we used them on bomb tails that got dissassembled several times, flown around in very aggressive environment etc. with no problems. If to the MIL std they are rated for 5 time use as I recall and in practice are OK for more than that in most applications.

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at

http://eng-tips.com/market.cfm?

 

[unclesyd]

You might want to look at this type fastener that eliminates the nylon patch.
ITW used to be good at providing samples for testing and prototypes.

http://itwmc.com/content/default.aspx?cID=82