Red Loctite for base screws?

Mar 1, 2017
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Middle Tennessee
#1
My base became loose during a recent range session. I installed it with medium strength blue threadlocker and torqued to 20 in/lbs. These are 6-48 screws. I'm going to order new screws and want to put high strength red Loctite on them when I reinstall. Has anyone used the red before?
 

JRodMT

New Hide Member
Feb 21, 2018
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#2
No I always use blue and never an issue but I always retorque after the 1st 100 rounds. If it continues to be an issue, I’d bed the base. I also go 25 lb/in on all 6-48 screws. Is the base steel or aluminum?
 

bjay

Private
Oct 19, 2009
2,940
83
48
Aloha state HI
#3
I had the same issue with magnum cartridge..i red lock tite that 8/40 screws and carefully and slowly did 30 inch torque..when i went and re barrel also recoated barrel action.i asked my smith to threat my action like a integrated rail.do not remove nor loosen rail..i dnt see any reason those base should be on and off to begin with
 
Mar 1, 2017
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Middle Tennessee
#8
I cleaned everything with rubbing alcohol prior to assembly (I will use acetone this time). I'm going to go with the red loctite and torque to 25 in/lbs. It's only a .308 and I'm honestly surprised that the blue failed.
 
Apr 13, 2012
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Cheyenne, WY
#10
You can use red loctite, but you'll need to heat the screws if you ever want to remove them. I've heard of people heating the screws with a soldering iron to isolate the heated area to just the screw. I use blue and have never had an issue, like others have said, make sure all threads are very clean.
 

GH41

Sergeant
Mar 18, 2014
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#11
The people that say they breakdown red with a soldering iron are full of shit! They are the same guys that claim you can use a Dremel tool fix anything!
 
Feb 25, 2017
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#13
Those folks using Loctite need to be aware that when wet, Loctite acts as a lubricant so when screws are tightened to 35 inch pounds, the real torque might be in the neighborhood of 45-50 inch pounds. Danger Will Robinson!
 

Mordamer

Professional Know It All
May 11, 2010
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Hooker, OK
#14
Those folks using Loctite need to be aware that when wet, Loctite acts as a lubricant so when screws are tightened to 35 inch pounds, the real torque might be in the neighborhood of 45-50 inch pounds. Danger Will Robinson!
This comment is complete nonsense. Using a lubricant on threads does not make the torque number magically increase from what is measured with a wrench. A lubricant simply reduces the amount of torque it takes to get a desired clamping force with a fastener because it drastically reduces the thread friction force. Loctite will go on with a much lower torque than it will come off because it hardens as an epoxy in the threads. Maybe this is what you are talking about.
 
Likes: Xander3Zero
Feb 25, 2017
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#15
This comment is complete nonsense. Using a lubricant on threads does not make the torque number magically increase from what is measured with a wrench. A lubricant simply reduces the amount of torque it takes to get a desired clamping force with a fastener because it drastically reduces the thread friction force. Loctite will go on with a much lower torque than it will come off because it hardens as an epoxy in the threads. Maybe this is what you are talking about.
Not as nonsensical as you think. Watch the video by Vortex, I would think they have some idea on this subject.
http://www.vortexoptics.com/video/how_to_tighten_riflescope_rings

From the Warne website:
"Warne does not recommend the use of threadlocker on our rings. When a threadlocking compound is applied to screw threads, it can act as a lubricant. When you torque lubricated threads vs. torquing dry threads, when using the same amount of torque, more pressure will be put on the scope tube due to the lubricated screw being easier to tighten."

I will walk my statement back a bit as the OP was asking about using threadlocker on his base and I was referring to scope rings and stand by my claim.
 

Xander3Zero

Sergeant of the Hide
Aug 10, 2017
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Rhode Island
#16
Let's be clear on this.

If you torque two screws, one dry and one lubricated with anti-sieze or even some loctite, to the same torque value, they will obviously both have the same torque value. The difference is that the lubricated screw will be seeing more tensile load (or clamping force in a bolt/nut) due to the reduced friction of the threads.

For example, here is the equation for calculating the applied torque based on the bolt tension, nominal bolt diameter, and coefficient of friction:

T = F * D * c

Where "T" is the applied torque, "F" is the bolt tension, "D" is the nominal diameter, and "c" is the coefficient of friction. Let's rearrange this equation to calculated the bolt tension from the applied torque:

F = T / (D * c)

Let's consider a rail that uses #8-40 screws, with a nominal diameter of 0.164", and assume a recommended torque spec of 15 in-lbs. The coefficient of friction for dry threads is typically around 0.20 and the for lubricated threads it is around 0.15. These are approximate values, and due to machining tolerances and the lubricant used, they can change a bit.

F_dry = (15/12) / [(0.164/12) * 0.2] ------> F_dry = ~457 lbf

F_lubed = (15/12) / [(0.164/12) * 0.15] ------> F_lubed = ~610 lbf

Both screws receive the same input torque, and the clamping force is increased relative to the ratio of the lubed friction coefficient to the dry friction coefficient.

As far as whether you should use loctite on scope rail bases or scope rings... I do, because I do not want them to come loose during recoil vibrations. In most of these cases, the recommended torque value is most likely conservative to prevent any damage in the case of over-torque. For an un-experienced torque wrench user, it is probably pretty likely that they could over-torque a #6 or #8 fastener by roughly 10-30%, so I am sure that the scope rail and ring makers take this into account. Also I am betting that they err on the side of caution when specifying torque values for scope rings because of the risk potential of damaging an expensive optic. I am sure they would rather have you torque the ring caps to a lesser value and risk your scope coming loose during recoil (which is unlikely if you torque properly and evenly), than give you a torque value with no margin for error that could cause you to damage a scope tube.

Basically, just torque your bases and ring screws slowly and evenly, and you definitely shouldn't have any issues with any of the quality makers' parts. I would recommend using some blue loctite on scope base, ring clamp, and ring cap screws. I've never had any of these screw come loose on me, and I've never had any trouble loosening the screws for removal later. Also never had any issues with leaving any marks on scope tubes from over-tightened ring caps; all my scopes have come off the rings looking absolutely brand new with no ring marks.
 

bjay

Private
Oct 19, 2009
2,940
83
48
Aloha state HI
#17
The last thing we want is chasing our tail during competition or hunting..just bcoz 1-2 screws loose...this happen to me while hunting scope (aluminum) base came loose so either dismount scope and tighten base and re install scope and go on but regardless its not not going to be dead on zero and situation like that completely ruined the rest of the day..using aluminum base on big magnum IMO is something you keep on watching.. aluminum is almost too soft for big recoil and sometimes cant stop screws from coming loose..i have no problem using red lock tite on base and turn action to INTEGRATED rail..base is not there to be on and off like rings or rings cap..if you're going to permanent (red lock tite) base i would bedd it on the process. I didnt when i replaced the aluminum base to steel from defiance.but defiance base is like V block with cut out middle of the base..
 
Mar 7, 2017
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#19
I personally only use blue with such small fasteners. IF you make sure everything is good and clean you shouldn't have any problem. If you end up using red I would recommend using a heat gun to free them prior to trying to loosen them. even with blue lock-tight i have begun to twist the torx bit before they loosened up.
 
May 15, 2011
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#20
I have one rifle on which the base screws came loose three times. First time no loctite so added blue. Next time used red and added new screws, loosened again. Something obviously wrong with the receiver holes! Last time epoxied base on with JB and ok so far. To the non-loctite guys what would you suggest when screws come loose? Sure a gunsmith can tap to a larger size, requiring a new base but not worth it on a beater.
 

Xander3Zero

Sergeant of the Hide
Aug 10, 2017
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Rhode Island
#21
I have one rifle on which the base screws came loose three times. First time no loctite so added blue. Next time used red and added new screws, loosened again. Something obviously wrong with the receiver holes! Last time epoxied base on with JB and ok so far. To the non-loctite guys what would you suggest when screws come loose? Sure a gunsmith can tap to a larger size, requiring a new base but not worth it on a beater.
What rifle, what scope base? Were the scope base screws included with the base, or did you buy separately? I would think if you can properly torque the screws and they feel like they thread in similar to any other machine threads you've ever experienced, then its not an issue with the receiver holes. If the receiver holes were shit, I think it would be pretty clear just by hand tightening the screws to them.
 
May 15, 2011
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#22
Xander I don't think the exact models matter that much, except to say this has never happened on the numerous other rifles I have. No indication of an issue when torquing the cleaned screws in cleaned holes (yes I'm slightly anal). Point is occasionally shit happens in many regards, and sometimes non-standard measures are called for to correct them. Meaning blanket statement such as NEVER to use something (like red loctite) are just recommendations for the general case. And eventhough I have not had a similar problem on my 300WM hunting rifle I did red loctite the base screws, wanting to minimize the possibility of Murphy's law getting me on that shot at an elk.
 

Snuby642

Sergeant of the Hide
Feb 11, 2017
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#25
I've screwed a lot over the years.
Several odd screw and thread pitch sizes have been mentioned.
We use NC and NF and some might use metric.
Not trying to be a smart ass but think you should check and make sure you didn't get hold of a wrong screw.
A thread pitch Guage and mike will tell real fast on the screw, a plug tap should go into the rifle without effort.
Do not force the bottom tap.
https://www.engineersedge.com/screw_threads_chart.htm
 

Xander3Zero

Sergeant of the Hide
Aug 10, 2017
368
94
28
Rhode Island
#26
Charlie, I guess in my opinion, there is nothing about the application of scope base mounting that would warrant red loctite in any scenario.

IF the threaded holes in your receiver seem okay, and you have a quality scope base (prefer with recoil lug), and quality machine screws, you should be fine using no loctite at all and just torquing properly, although I would recommend blue loctite because it is just extra security with no downside.

IF the screws are coming loose even with blue loctite, then I would say that changing to red loctite will likely not solve the issue. In this case, there must be some other variable causing the screws to come loose, and I don't think red loctite is the solution. If you find yourself in this position, I guess you could consider expoying the base permanently or some other means that has been mentioned here.

I work as a mechanical engineer in support of navy applications, and rarely ever see an bolted connection that uses red loctite. I see a great deal of load-bearing threaded connections that see high vibration environments, and we generally specify "Threadlocker, Blue" with the appropriate torque spec. I'm also pretty familiar with cars and do most of my own car work, and have never had to use red loctite on any application there either, again pretty vibration prone. Just my 2 cents, but sorry I can't offer much help if the blue loctite isn't working out.
 

EXTREMEPREJUDICE

Online Training Member
Oct 21, 2008
1,676
45
48
SE MICHIGAN
#27
The people that say they breakdown red with a soldering iron are full of shit! They are the same guys that claim you can use a Dremel tool fix anything!
LOL, "Dremel tool" and "Damage tool" are generally interchangeable. I only use red on things I don't ever expect to take apart. I imagine that's why when base screws come with thread-locker applied dry.................it's always blue! If you take the few minutes to properly bed the base you won't have to worry about which Loctite.
 
Mar 1, 2017
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Middle Tennessee
#28
I've been too busy to get this issue resolved but I finally found time last night. These are actually 8-40 screws. I ordered new ones that were long so I could trim them since the Badger screws were short. The head on the new ones was too big for the counterbore on the base. I opened them up on a mill. I suspect the small head on the original screws and the lack of full thread engagement on the receiver diminished the holding capability. I still used the red Loctite 272 to make sure this isn't an issue again. Pic attached gives you an idea of how much bigger the new heads are. 20180316_214853.jpg
 

Waorani

Back to the Island
Feb 14, 2017
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Auburn, AL
#31
8-40 hex/torx head screws are available that only require enlargening the through hole w/o having to open up the counterbore for the head. And with the screw heads filling the counterbore, all your hole locations are going to have to match perfectly in the base/receiver.
 
Jul 28, 2017
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#32
The people that say they breakdown red with a soldering iron are full of shit! They are the same guys that claim you can use a Dremel tool fix anything!
Red only need to get to around 550F to soften, a small soldering iron can do that easy. Have done it many, many times. An electric one works fine, but a small butane iron gets hot a lot faster than a plug in one, so if ever find yourself having to remove a bunch of rails that are all red loctited one, that is the ticket.
 
Feb 13, 2017
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#33
IF you don't want to be concerned with anaerobic adhesives and their temperature release thresholds, consider using
Vibratite-VC3 which is similar to Nylok style compressible thread applied adhesives. It is adjustable, removable, etc. yaddah yaddah. Check it out.

IMG_8348 copy.JPG
 
Likes: Jay McLean

GH41

Sergeant
Mar 18, 2014
400
8
18
#34
Bullshit! Obviously you have never tried your suggested method of breaking down red. You could stick one small soldering iron in your dick hole and another on the screw. Your dick would freeze before the screw breaks loose.
 
Feb 13, 2017
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#35
IF I have to transfer heat to a limited screw head surface to release anaerobic thread adhesives (e.g. blue / red loctite), I try using my soldering gun with several different modified tips based on screw head configuration, to maximize heat transfer to the head of the screw. If a small torch is needed apply Brownells Heat Stop Paste around the screw head to limit any collateral damage from the heat source. Even too much blue Loctite can cause the screw to not be amenable to removal by heat for fear of damaging adjacent electronic elements; this RMR mount required drilling and extractor use.

Screen Shot 2017-04-01 at 4.21.46 PM copy.png Screen Shot 2018-03-17 at 8.57.18 PM.png
 
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Jul 28, 2017
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#36
Bullshit! Obviously you have never tried your suggested method of breaking down red. You could stick one small soldering iron in your dick hole and another on the screw. Your dick would freeze before the screw breaks loose.
Yeah man, 16 years of building rifles (with most of that being sniper rifles for the Marines where we always used red loctite) and I have not tried removing a base with red yet using a soldering iron. You really need to bark up a different tree if you think you are going to convince someone with online bravado.

I assume you are trolling, but I still respond because you are going to lead other astray with your nonsense.

A soldering iron placed on the screw head of a scope mount screw will be more than enough to break free red loctite; anyone that says otherwise is talking out their ass. They have either never tried it or tried using a soldering iron on some much larger screw, like a dummy.
 
Mar 1, 2017
136
13
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Middle Tennessee
#38
8-40 hex/torx head screws are available that only require enlargening the through hole w/o having to open up the counterbore for the head. And with the screw heads filling the counterbore, all your hole locations are going to have to match perfectly in the base/receiver.
I bought the wrong screws and didn't want to wait for the replacements. There was enough clearance for everything to line up and assemble easily. I zeroed the rifle and took it out to 600 yards today, it tracked just fine.
 
Feb 13, 2017
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#40
Just for the heck of it I was trying to decide how to simply demonstrate heat transfer down a 8-32 X 1/2" screw using a soldering gun with one of the flat modified tips I mentioned above. Here the screw is held by magnet with solder wrapped about the threads near the tip. The melting point of this solder is ~ 465 deg F; red loctite is ~ 500 deg F.
It took less than 30 seconds to melt the solder.
video:

https://www.dropbox.com/s/w26o3l8sr92d8bf/IMG_8357.MOV?dl=0

Of course thread length and being installed allows for surrounding metals to act like heat sinks so it can take a little longer based on these other variables, any how it seems to make the point that the method works quite well.

Having such information can also be useful in planning your placement of heat sensitive thread lockers on the threaded parts to be mated. I generally use the adhesives close to the screw head, as it is the shortest length for heat to travel and the adhesive doesn't get displaced / thinned on insertion as the fastener runs thru its length to final position.

Finally, using a magnet is an easy way to hold screws while some adhesives are curing before installation.

IMG_7110 copy.JPG


IMG_8352.JPG IMG_8353.JPG IMG_8354.JPG IMG_8356.JPG Screen Shot 2018-03-18 at 1.44.42 PM.png Screen Shot 2018-03-18 at 1.43.12 PM.png
 
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Snuby642

Sergeant of the Hide
Feb 11, 2017
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#41
Had to read that twice!
Thought you were going to solder them in place.

Have you tried this with rockset?
 
Feb 13, 2017
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#42
^^^Rocksett is a silicate-based adhesive with a temperature release threshold of ~2,000 deg F.....one would change the temper of the metals by the time that much heat was delivered...so heat is never the answer and is why many mfg.s of muzzle brakes / suppressors use it to secure threaded devices as a rapid fire suppressor temperature may exceed 1,000 deg F. Soaking in water, some warm it up a bit, dissolves the silicate then apply the wrench.

I confirmed the best method of release with the mfg. of Rocksett a few years ago.

Screen Shot 2018-03-18 at 3.32.52 PM.png
 
Feb 13, 2017
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#43
8-40 screws are commonly used for scope mounting, available in different size T-heads as well (T-10, T-15). I try never to use a non-Torx head style as the other configurations are not nearly as secure to the torque wrench as Torx or Torx-plus styles. Some even come with blue Nylok already applied to them. I made a chart a few years ago calculating the difference in length of thread engagements based on screw size and TPI. You can see that the 8-40 has almost one more inch of engagement than a similar length 8-36. The more length the force of engagement can be distributed over generally a more secure situation. You may also notice that the 40 TPI is the only one that is common among #4-#8 screw options.

Screen Shot 2018-03-18 at 3.44.18 PM.png IMG_8363.JPG IMG_8362.JPG
 
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Snuby642

Sergeant of the Hide
Feb 11, 2017
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#44
You guys are right!
Drilling into shorter materials would incur using more treads per inch.
In the old days I hand tapped critical small components because the machines would break the taps.
0-80, 2-56, 4-40 etc.
Newer better cnc machines and cad/ catia based programs greatly reduced that.
Problem then was the specs didn't allow for tooling necessities (end play ) we will call it.
Back to earning a living fixing busted stuff.

I did a lot of work in aluminum and we heilicoil all that, so we then used the 8-32 screws.
The 8-40 would be better in a short screw in steel.
I forget some stuff, just sounded like something was wrong in the setup.
 

GH41

Sergeant
Mar 18, 2014
400
8
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#45
Just for the heck of it I was trying to decide how to simply demonstrate heat transfer down a 8-32 X 1/2" screw using a soldering gun with one of the flat modified tips I mentioned above. Here the screw is held by magnet with solder wrapped about the threads near the tip. The melting point of this solder is ~ 465 deg F; red loctite is ~ 500 deg F.
It took less than 30 seconds to melt the solder.
video:

https://www.dropbox.com/s/w26o3l8sr92d8bf/IMG_8357.MOV?dl=0

Of course thread length and being installed allows for surrounding metals to act like heat sinks so it can take a little longer based on these other variables, any how it seems to make the point that the method works quite well.

Having such information can also be useful in planning your placement of heat sensitive thread lockers on the threaded parts to be mated. I generally use the adhesives close to the screw head, as it is the shortest length for heat to travel and the adhesive doesn't get displaced / thinned on insertion as the fastener runs thru its length to final position.

Finally, using a magnet is an easy way to hold screws while some adhesives are curing before installation.

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Sorry. I appreciate your effort to simulate the OP's issue but you exercise isn't relevant. I don't blame you for not using valuable components but let's get closer to a receiver with an aluminum scope base installed with red. Say you take a piece of 1/4 by 2 inch steel bar stock a foot long, drill and tap a hole in it, and fasten a piece of 1/4 by 1 inch aluminum 6 inches long using red. Take it off with your soldering gun. Your example with solder doesn't take the heat sink properties of everything into consideration.
 
Feb 13, 2017
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#46
Not attempting to convince anyone of anything. Empiric experience on real situations shows it works almost every time. When heat doesn't work simple drill extraction is Plan B.; not a problem, takes 5 min rather than one minute of heat.

Aluminum transfers heat quite nicely. The heat has to conduct down the mass of the screw before it moves to the surrounding metals. That's all I have for the crowd. It's always more difficult to prove the negative. Show us how it doesn't work. Signing off on this thread.
 
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Likes: Snuby642
Nov 24, 2011
594
9
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Brighton, IL
#47
Just for the heck of it I was trying to decide how to simply demonstrate heat transfer down a 8-32 X 1/2" screw using a soldering gun with one of the flat modified tips I mentioned above. Here the screw is held by magnet with solder wrapped about the threads near the tip. The melting point of this solder is ~ 465 deg F; red loctite is ~ 500 deg F.
It took less than 30 seconds to melt the solder.
video:

https://www.dropbox.com/s/w26o3l8sr92d8bf/IMG_8357.MOV?dl=0
No fair! You used a magnet. Everyone knows magnets are magic!

Seriously. kudos to you for this demonstration. Science for the win!
 
Jan 8, 2004
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#48
Anytime the subject of small screws coming loose the crowd is always divided between those who claim red locktite is the devil and those like me who've used it on all kinds of scope size screws since it became available with no problems. If you're still queasy about using red I've found the stick version of blue to work much better than the liquid.
 

D_TROS

Flag-Sword-Cross
Aug 19, 2010
1,293
65
48
North Denver, CO
#49
Couple things not mentioned from my experience.

One, use the red Loctite to bed the base as well. takes an extra second to squirt a little extra on top. bolt down torq gtg.

Second, make sure the hole you put in the locktite isn't the one that goes all the way through the action into the lug recess. I accidentally locktited my bolt closed once. not my brightest moment. Took awhile to work it loose and pick it out but just be careful and use as much as needed.

very important thing only mentioned once...make sure it is 100% degreased.

DT
 
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