Use of teflon tape for red dot mounting screws

[w4rwf]

Simplistic question. Has anyone tried teflon tape on the screws that mount your red dot optic? I understand blue loctite, purple loctite and vibra tite. Would like to know if it's a solution or not. Searching on the net doesn't really get me any answers which may be an answer unto itself.

Thanks!

[Joe4d]

a solution to what ?

 

[RangerTrace]

 Not sure they make tape that small.......Blue lock tight works great if you shake the bottle!!  It's nothing more than colored water if you don't...

[Sarge]

Is your dot leaking? seriously, blue loctite.

[lefty o]

30 minutes ago, Sarge said:

Is your dot leaking? seriously, blue loctite.

this, or vibratite vc3.

[CHA-LEE]

Teflon tape does the opposite than Lock Tight when it comes to adding friction to threads. Why on earth would you want to make the optic screws easier to loosen up???

[Dr Mitch]

1 hour ago, CHA-LEE said:

Teflon tape does the opposite than Lock Tight when it comes to adding friction to threads. Why on earth would you want to make the optic screws easier to loosen up???

Science isn’t for everyone

[hiker88]

3 hours ago, Sarge said:

Is your dot leaking? seriously, blue loctite.

[w4rwf]

Yeah, do a lot of underwater shooting. Helps if the dot doesn't leak. And Thanks cha-lee, you're the only one that actually answered my question. Just purchased a new pistol and the gun shop put the optic on it. Screws loosened up after several magazines. I took the optic off, cleaned threads and put vigorously shaken thread locker on the screws and torqued to 15 in lbs per fat wrench. Waited till the next day and went back to the range. Optic came loose after 6 magazines again. Bottle of loctite is definitely not new so maybe need to go get another bottle of it. Teflon tape tightens up tolerances between the threads and that was the reason for my question with the thought that maybe tighter tolerances would hold the screws in place better. Added benefit is it keeps my dot from leaking also.

[barry]

In my experience a lot of dot mounts the locator posts are to loose and dot moves around shakes screws loose. Pins should be almost a light press fit.a dab of epoxy with release agent on pins may help.

[IHAVEGAS]

14 minutes ago, barry said:

In my experience a lot of dot mounts the locator posts are to loose and dot moves around shakes screws loose. Pins should be almost a light press fit.a dab of epoxy with release agent on pins may help.

 

Or a layer or three of teflon tape under the sight? Just a thought and perhaps something not workable but it does seem like there has to be something going on similar to what you mention. 

[w4rwf]

Thanks barry! This red dot has no pin holes and the mount(slide) is a smooth plate. It's just the 2 screw holes to hold the dot in place. The pistol is a p220 in .45 acp and the slide from the factory accommodates the sig sauer red dot or dpp. holosun makes one that is a direct fit to the slide also without having to use adapter plates. I went with the holosun. Looks to me to be a screwy way to mount a red dot but i'm supposin that a lot of people have managed to get one to stay in place and are happy with them. I'm gonna try again with a fresh bottle of loctite and if that fails I may contact sig. Guessing it could be a possibility the screw holes are not at spec for some reason. Not a scientist or machinist either.

[Joe4d]

Marine engineer here,, buy the blue paste stick loct tight.. and thats for everything , stop messing with the stupid liquids .. especally in holes.. The liquid can cause a hydraulic lock.. a little paste on the threads way mo betta.
But Id say you have a machining problem, not a thread locker problem.. Sight body is torqued, or not going down square due to the cuts , hole placement, etc.. Not much you can do at this point. A layer of tape between sight and slide, may compress and take out a bit of slop that is allowing some movement... 

[w4rwf]

Thanks Joe4d! I just ordered a set of aftermarket screws to replace the ones from Holosun. After several more hours of scouring the internet it seems there are others who have the same problem. A new set of aftermarket, quality screws and the blue loctite paste seems to have solved their problem. Both should be here next week. Maybe I can finally get this thing sighted in, quit wasting ammo and have some fun with it.

[MikeBurgess]

6 hours ago, w4rwf said:

Thanks barry! This red dot has no pin holes and the mount(slide) is a smooth plate. It's just the 2 screw holes to hold the dot in place. The pistol is a p220 in .45 acp and the slide from the factory accommodates the sig sauer red dot or dpp. holosun makes one that is a direct fit to the slide also without having to use adapter plates. I went with the holosun. Looks to me to be a screwy way to mount a red dot but i'm supposin that a lot of people have managed to get one to stay in place and are happy with them. I'm gonna try again with a fresh bottle of loctite and if that fails I may contact sig. Guessing it could be a possibility the screw holes are not at spec for some reason. Not a scientist or machinist either.

One guy I know puts a thin layer of rtv silicone under the dot to "glue " it to the slide in an attempt to limit any movement.

 

I would do whatever I could to get a solid contact between the front of the optic housing and the front of the optic cut if at all possible to carry the recoil load.

[w4rwf]

I can push the optic all the way forward in the cut and the screw holes seem to align perfectly. I also used a thin piece of cardboard behind the optic while I was putting the screws in and was able to remove the cardboard with about the same effort as it was to slide it in. I think the optic is all the way forward. But a light layer of RTV underneath may well be a great idea. Thanks!

[-JCN-]

31 minutes ago, MikeBurgess said:

One guy I know puts a thin layer of rtv silicone under the dot to "glue " it to the slide in an attempt to limit any movement.

 

I would do whatever I could to get a solid contact between the front of the optic housing and the front of the optic cut if at all possible to carry the recoil load.

I do this with E6000 glue. Rubs off like rubber cement and also softens with mild heat to help release later. 

[w4rwf]

26 minutes ago, -JCN- said:

I do this with E6000 glue. Rubs off like rubber cement and also softens with mild heat to help release later. 

Thanks! Another great idea.

[-JCN-]

19 minutes ago, w4rwf said:

Thanks! Another great idea.

I’d probably use it to space fill the nose and tail of the optic in the cut too. 
 

Don’t use very much underneath on non structural electronics covers that can pull off. Ask me how I know.

[392heminut]

11 hours ago, barry said:

In my experience a lot of dot mounts the locator posts are to loose and dot moves around shakes screws loose. Pins should be almost a light press fit.a dab of epoxy with release agent on pins may help.

Red Loctite works better for this. I've used Red Loctite for years to fill the gaps on stake on front sights for 1911's and never had one shoot loose.

[TheOneTrueAndre]

Why? Blue Loctite is so easy...

[Yeti]

When you get waaaaaay off the well traveled path, ask yourself why.  

 

Just use boring Loctite blue.  Paint mark the mounting screws if you are worried.    

[zzt]

I sounds more like you have a thread problem.  The new screws you bought may not be any better than the ones that came with the dot.  In my experience, most screws that come with, or are bought loose aftermarket are junk.  There are few exceptions.  Go to McMaster Carr and buy a box of 5-40 USA made screws.  Buy another box of a longer length is you are planning on using a thumb rest.

 

IF your frame holes were tapped properly, AND you use the good screws, YOU DO NOT NEED LOCTITE.  Simply screw them in and torque them.  If they ever come loose, your frame holes are crap.  Now you will need blue Loctite.

 

BTW, NEVER reuse 5-40 screws.  Once they have been torqued down once, they will never hold as well again.  Always use fresh screws.

[w4rwf]

Thanks zzt! The new screws are supposed to be of a much higher quality. Will see after they get here and how well the dot stays in place after a proper cure time with the loctite paste.

If in the end they still don't hold I will contact SIG and see if they will make this right. I'm new to SIG products. This is my second SIG. Happy with my first purchase from them, a P365 Nitron for pocket carry and now this P220 .45 and from what I've read SIG has good customer service. Hopefully I won't have to find out.