Mounting Troy BUIS?

[wintermute]

I bought a Troy fixed rear BUIS and mounted it as per the instructions yesterday - putting it at the rear of my rail, putting blue lock-tite on the threads of the securing bolt and tightening until it wouldn't move. Today I went to the range and the sight started wiggling within 20 rounds. I got home and it was easy to unscrew the bolt. The only two things I can think of that I did wrong:

- I tightened the bolt until snug, I didn't really crank on it for fear of damaging the aluminum.

- I didn't give it a full 24 hours to cure before shooting, it was more like 18 hours.

So how did I screw up? Thanks.

[ucrt]

Maybe it had Loctite on it when you where tightening and that was the resistance you were feeling?
You have to degrease the nut and bolt threads before applying Loctite.
Don't oil after it has been Loctite'd, the oil can creep and break the Loctite joint.
Maybe the recoil, stripped the threads out after a few shots because it was over-tightened?

Were you able to get it back tight again?

[500grains]

Maybe it was a message from Allah to use red Loctite?

http://www.electronicplus.com/images/products/27100.jpg


[Just kidding. :D ]

[orionz06]

Red loctite, really snug, as it it were steel, and made sure to keep it cool and dry for a day or two. I index marked it and checked it the first few times, not it gets looked at as all other index mark items do.

[wintermute]

Maybe it had Loctite on it when you where tightening and that was the resistance you were feeling?
You have to degrease the nut and bolt threads before applying Loctite.
Don't oil after it has been Loctite'd, the oil can creep and break the Loctite joint.
Maybe the recoil, stripped the threads out after a few shots because it was over-tightened?

Were you able to get it back tight again?

Nope. All concerned parts and parts in the vicinity were dry and clean, with no hint of oil (although, what should I use to degrease - mineral spirits?). There was no sign of stripping, either of the threads or damage to the rail. The bolt unscrewed with the same amount of force used to tighten it and I was able to get it tight again.

Looks like red lock-tite is the way to go.

[JSantoro]

Before you do that, double-check one thing:

Prior to going to full-tight, did you apply forward pressure on the device and ensure that there was no space between the back side of the rail slot you put it in and the forward side of the rail lug on the BUIS? I know that it's in the instructions, but it's overlooked more often than one would think.

If not, what tends to happen is that space that may be left gives the sight somewhereto go under enough recoil impulse. A jackhammer works with a lot of little strikes, not one big one, so however many rounds you fired may have been enough little hits for the thing to get shaken loose.

So, on the offhand chance that you didn't make sure it was pushed all forward, re-mount it, apply forward pressure on the sight while you tighten it down. By the symptoms you mentioned, it's the first thing I would look to do from a troubleshooting standpoint.

If you DID apply forward pressure while mounting....disregard the aboe, it may be that you have to use the red.

[wintermute]

I'm not sure if I did Jim. As i tightened, I would keep wiggling the sight base until it "set" in place once it was tight. I'm not sure if that's the same procedure you're describing. I would sure like to stay away from the red loctite.

[Thomas M-4]

Check and make sure there is no oil on the threads just a hint will prevent the loctite from setting correctly. Another tip I have better results applying a heavy band at the first 3-4 threads no more as when you screw it in the threads will evenly disperse the rest down the rest of the length of the thread shank.
I hope it makes sense and helps.

[orionz06]

I removed my red loctited Troy front without issue. I removed the index marks with solvent and used a small torch to heat up the threads and it came out disturbingly easy.

[ucrt]

Nope. All concerned parts and parts in the vicinity were dry and clean, with no hint of oil (although, what should I use to degrease - mineral spirits?). There was no sign of stripping, either of the threads or damage to the rail. The bolt unscrewed with the same amount of force used to tighten it and I was able to get it tight again.

Looks like red lock-tite is the way to go.

===============================
I degrease with 92% alcohol first and then use Carburetor Cleaner. Mineral Spirits takes to long to dry. Might be the problem.
The clamp could have been cock-eyed in a bind and a little shooting shook it loose.

[JSantoro]

I would keep wiggling the sight base until it "set" in place once it was tight. I'm not sure if that's the same procedure you're describing.

Not really, that's more like the start of it.

-Place it where you want it.
-Tighten enough that you could turn the gun upside down and not have the BUIS fall off; should still be able to feel/hear it move back and forth in the rail slot if you wiggle it.
-Push on the thing, toward the muzzle and maintain that hold.
-Tighten fully while maintaining that hold.

Otherwise, the chance of a gap and subsequent room to move under recoil impulse exists. Even loctite won't hold it if the thing has room to move, fully cured or not, red or not.

[ST911]

Clean and degrease the mounting screw.
Apply blue loctite.
Install the sight and clamp, push the sight forward while tightening down.
Put a witness mark on the screw, as well as the sight base and receiver.

There shouldn't be any need to use red loctite.

[mark5pt56]

I've installed a few of these and believe me, you can gorilla grip the piss out off that screw. It won't break and with Blue it won't loosen.
As mentioned, install per instructions and it will be fine.

[wintermute]

Okay, so my plan of attack (with my understanding of it, because I'm an annoying engineer and have to understand every little minutiae) is:

- degrease everything NEAR the sight and rail with denat alcohol (on a second look there was a bit of oil on the bolt)
- blue loctite the threads
- after inserting the bolt, jam the site base forward (am I right in thinking that by doing this, I'm making sure that the entire length of the bolt is up against the rail plateau in front of it, otherwise there might be some slack that could be disguised by a corner of one of the jaws binding to the rail)
- crank on the bolt with a screwdriver like I mean it.
- don't touch the damn thing for a couple of days.

[orionz06]

My answer, as an engineer who appreciates minutia, is yes. The other reason to push the sight forward is the response to recoil. The final movement of the gun will result in the rail mounted items to be pushed forward. Mounting them there will give the best results.


ETA: My new light mount arrived and I relocated my Troy front sight and my red loctite was easily removed with my above mentioned method.

[wintermute]

Thanks everyone.

Now, this is moving into the realm of paranoia, but considering that it's an hour drive to the range and the cost of rounds nowadays, I just want to make sure I have all of my ducks in a row...

- Should I scrub the bolt threads with a wire brush to try to get the coating off?

- Am I correct in assuming that accidental oil seepage won't hurt the blue loctite once it's cured?

[ucrt]

I like to use a fine wire "toothbrush" with a little carb cleaner to knock off what is loose on the screws and then I use tobacco "bristled" pipe cleaners to clean the female threads out. The bristled pipe cleaners have stiff bristles mixed in with the normal soft ones and they are more aggressive than regular pipe cleaners. I spray a little carb cleaner on the pipe cleaner and roll it between my fingers to spin the pipe cleaner in the threaded hole. I just keep using fresh PC's until they come out clean.

I read somewhere (I think on the LocTite site) that Loctite Threadlocker is not "oil resistant". Anywhere around a LocTite'd part, I try to use grease instead of oil because grease doesn't migrate as bad as oil. I guess that is why they make a Threadlocker and a Thread Sealant??

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