Loctite- permanent or removeable

[mikehoover]

I am about to order some Loctite from Aircraft Spruce and am wondering whether to get the permanent or removeable type. I'd rather only have to purchase one since it is expensive. Installing the flap rod end bearings is what has gotten me to deal with this. Comments? Thanks!

[dan]

This is just my opinion, but I didn't use any thread locker on either end of the flap pushrods. The end that threads into the flap goes into a nutplate, so that's a locking mechanism on its own -- I did use an internal tooth lock washer there nonetheless. So that end ain't goin' anywhere. And on the top end, at least on the RV-7, there's an AN4-xA bolt going through an AN365 nylok nut -- that end's not going anywhere either.

As for the male rod ends that thread into the pushrod itself, as long as you have enough threads engaged on both ends, even if the locking nuts got loose, the rod couldn't come loose...it would rotate in one direction or the other, but bottom out before it came off the other end. And if you tighten the locking nuts, it's not goin' anywhere. And obviously you do inspect this prior to every flight.

You could use loctite on the threads there, but I would definitely use the "less permanent" type. That's just my opinion. Early on I did make an adjustment or two on the flaps.

Again, just my OPINION.

[alpinelakespilot2000]

Mike--Loctite brand is expensive, but if you go down to your local autoparts store they will have generic brands with different types (permanent, tool-removable, self-wicking etc.) that correspond to the Loctite brand's types and they are MUCH cheaper.

Dan may be right regarding not really needing the loctite, but the RV9 plans do specifically instruct us to use loctite on the rod end that goes into the flap (and platenut).

[jcoloccia]

Originally Posted by dan

I would definitely use the "less permanent" type.

LOL...yeah, I made that mistake some years ago. I have a bit more experience with this now, and I can tell you the permanent stuff is designed to be removable only with heat (think heat gun or torch). In the case of bolts/screws, you'll almost certainly strip the head or twist it off before breaking it free without first heating it to about 400 degrees.

[Jekyll]

I dabbed loctite on the the screws that hold a D-sub backshell together for a connector in an inaccessable location. The next night I found the backshell had crumbled under to it's own weight! Luckily, the harness was still on the bench and not installed yet. Was I ever surprised! A striking chemical mismatch indeed. I should really read more directions, it probably warns about plastics.

Jekyll

[redbeardmark]

I used a little swipe of grey silicone sealant. It provides just enough grab to keep the nuts from loosening, but remains fairly soft. Not saying that it is a replacement for all Loctite applications, just this one.

[SteinAir]

The "Blue" or medium locktite is the type to use if you want to remove things later, but still hold them in place. This stuff shouldn't be used around any plastics, many years ago some builders found out the hard way on their canopies....it'll do a number on plexi.

Anyway, like others have said, the "generic" versions of the Locktite brand are just fine...we use Dynatex.

Cheers,
Stein.

[jarhead]

In the Loctite brand, avoid red or green. These are the permanent varieties. Green requires impact tools and welding torch heat...