Comment by Hardcore on October 30, 2011 at 2:53am

It should not be able to attack nylon 9 or nylon 66, it sounds like there is something else mixed in with the nylon (maybe PC, ABS), if the nuts are from a China supplier then that would explain it, the nightmare of my life was bloody Chinese plastic suppliers and their fiddles.

Get a nut and drop it in some nail varnish thinner.

check out this guide

http://catalog.gpi.net/Asset/Chemical-Compatibility-Ver-6.pdf

Comment by I.S. on October 30, 2011 at 3:20am

Just few weeks ago I did a test on a M2 nylon bolt and nut with Loctite 243 (aka Blue Loctite) to check if that was useful.(and yes, I know that nylon is already a locker, but I wanted to know if I could enhance the the thread locking properties)

After a few hours (3-4h?) the bolts I tried to unbolt it and both seems ok, but I noticed no locking properties which surprised me.

I will try to make a second more scientific experiment next time.

Comment by Hardcore on October 31, 2011 at 2:54am

That is because despite what you may hear , nylon is usually self lubricating:- that means a form of lubricant is expelled from inside the material as part of a continual chemical process.

 

 

Comment by I.S. on October 31, 2011 at 3:32am

@Hardcore

So nylon bolts and nuts are self locking AND self lubricant?
That sound surprising.

Comment by Hardcore on October 31, 2011 at 7:23pm

yep.....

They are mainly self locking because when under a  minor torque they stretch , thereby pulling the nut threads into the bolt threads more strongly, the key is that you do not over tighten them so that the "stretch" is made permanent and they fatigue and then fail. A lubricant only really works if the surfaces can move over one another freely, even if you loosen off a nylon nut & bolt they will still self lock to a certain extent if the threads are molded correctly.

I spent a significant amount of time looking at Nylon, PC &PE when we produced a cheap mechanical plug-in timer that had to run reliably 24/7/365/5

Comment by I.S. on November 1, 2011 at 3:11am

@Hardcore: Thanks for the explanation.

Comment by Ben Schwehn on November 14, 2011 at 3:11pm

Just want to add my experience:

I used locktite (or rather a similar product called Hypo Fix It) on my jdrones frame and it really had a terrible effect not only on the nylon screws (caused them to break and fall off) but more significantly also on the plastic parts of the frame (clanding fins, dome and motor mounts), causing those parts to crack and fail much more easily. I did really not expect this, after all using glue on plastic parts is usually fine.

Moderator Comment by Sgt Ric on November 14, 2011 at 3:52pm

It seems to me that besides the plastic eating theory several people have mentioned, Locktite expands as it dries, with disastrous results for plastic frames, etc.

Again, a good product for metal on metal, but the moral seems to be, keep away from plastics.

 

An expensive lesson in my case.

Turned an R/C Graupner Bell helicopter into a display model.

Comment by Martin Poller on November 14, 2011 at 4:36pm

Thanks all for your individual experiences, I don't feel as much of an idiot now for using it on the nylon bolts, I'm wondering now if I should strip my quad back down and replace all the nylon connectors in the frame or just leave them now as the damage is done. They don't seem to have deteriorated any, but there again it could be quite spectacular if the frame came apart in mid flight!!

 

Comment by Hardcore on November 14, 2011 at 10:39pm

I think that before we say that a particular chemical degrades another one, we have to be sure that the chemicals/materials we are testing are actually what they claim to be.

You would be very surprised at what gets passed off as 'plastic' when you buy parts online, and you would be horrified to learn than some of it may actually be recycled medical waste, such are the horrors to be found in the market that is fasteners, ESP. when they are sourced in  Asia.

 

A quick check of the Loctite site and the relevant data-sheets make it vey clear exactly what a given product is compatible with and when it should be used. The moral is RTFM, or in this case RTFDS.

 

 

Comment

• ‹ Previous
• 1
• 2
• 3
• Next ›
• Page