Thread locker info

[armorer951]

Found this interactive thread-locker selection tool at the Henkel website. Good info regarding the selection of the correct product for the job and some additional, specific data about their threadlocker products......including a new product called "Quick Tape 249" that is applied to the thread or joint surfaces as "tape" rather than the traditional liquid.


http://catalogs.na.henkel-adhesives....gt=11&lang=enu

[steveno]

if you think that you might have to loosen a screw at some point in time use blue Loctite or even clear fingernail polish. if you are REALLY sure you won't have to loosen something but want it to stay tight use red (or maybe green Loctite) Loctite. I will admit that there are very few reasons to use the red Loctite and even fewer reasons to use green Loctite on a gun.

[WR Moore]

I finally got the link to load. Before people start throwing thread locker advice about, I'd STRONGLY suggest getting the application charts for the particular brand and follow it. The one property I don't see listed in the chart is the fill capability ( compensates for fit quality). This can have a major impact on product selection. I also don't see the 271 that I've used for decades to help lock 1911 swaged sights in place. Permatex 27140 seems to be an adequate substitute.

I know Loc-Tite has several compounds with the same colors, but different numerical tags/names and very different properties. I've run into this with at least one other brand. No big deal (usually) if you're expecting more holding properties than you get. It can be a major issue if it goes the other way around.

[chief38]

IMHO TOO MANY misuse Locktite Products or use the wrong version of it. I also find that very few people actually prep the work properly prior to use.

IMO Red (permanent) should only be used in a situation that will never ever require the possibility of disassembly for repair. Even though they state that it is removable with heat - that is sometimes not truthful, practical or applicable. When trying to use heat to remove, if the parts you are heating are heat sinked to a large shaft or piece of metal, many times the heat is drawn out faster than the Locktite is being loosened and the removal process is unsuccessful. Secondly, there are times that Locktited parts are too close to materials that are easily damaged from heat or times you just can't get in to apply the correct amount of heat. ONLY use the Red when you never ever will have to disassemble (at least IMHO). Blue (removable with hand tools and using no heat) has never failed me and never opened up unintentionally! As with ANY brand or type of Thread Locker or parts locker, the area should be thoroughly cleaned out with Alcohol, Acetone, or alike. Make sure they are also perfectly dry prior to application and use only enough to get the job done - DON'T slather the parts or threads with the stuff! Locltote will migrate and bond things you don't want bonded if too much is applied!

For 99.9% of most applications Blue is all you will ever need (IMO). I do use the Red when I am making Tools and Fixtures in my Workshop that I NEVER want or have to separate, but Blue is my Go-to. Again, prepare work properly and don't over apply.

NOTE #1: Some manufacturing Company's use pre-coated thread lockers on screws and even though it is red in color, it probably is not Locktite - just another mild strength locker that is able to be pre applied with longevity but is NOT nearly close to the strength of Locktite. This is not known to some - but now you know.

NOTE #2: As most here already know...... I almost never use any Locktite on Firearms as I have never seen any reason to if the gun is properly assembled with properly torqued screws. Thread Lockers are NOT a substitute for incorrectly tightened screws! While I have seen some screws on firearms assembled with a thread locker of some sort, I do not believe it to be Locktite and is not all that strong - at least that has been my experience. I do not believe the red colored thread fastener on S&W Yoke Screws is Locktite - just a mild keeper.

[OKFC05]

Dawson Precision uses Green to wick under sights after you have them sighted in. I tried it and it works. No mess, no failures.

[1MoreFord]

Let's get some things straight. The Red non-removable will Definitely remove with heat. I cooked a number of compensators off my 1911 barrels when attached with Red Loctite. I even did the same with the high temp Green Loctite. Finally wound up locking the comps in place with epoxy thanks to info from J. Michael Plaxco.

[DWalt]

I remember hearing this but never tried it. If you really want to lock two threaded parts together forever, putting a drop of tincture of Iodine on the threads will do that. Does anyone know about that?

[chief38]

I do agree that Red ("permanent") Locktite can be loosened with heat, but SOMETIMES heating a part or something to almost 500ºF is not safe, practical or do-able because of its location.

Just recently I needed to remove a large heavy pulley from a 1.5" motor shaft. The two Allen Head 5/16-18 set screws were countersunk and the only way I could try and heat them up is by inserting an Allen Key and heating the key itself - transferring the heat to the set screws. The 1.5" motor shaft acted as a heat sink and dissipated the heat from my Bernzomatic torch faster than it was heating up. Had I applied direct heat from the torch instead of using a sacrificial Allen Key, damage would have occurred to surrounding parts. Finally I decided to sacrifice the least expensive component which was the Pulley. I used a Double Cut Carbide Burr in my Die Grinder to remove the set screw that would not budge (only 1 out of the 2 came out with heat). After removal, I saw that whoever (at the Factory) applied the Red Locktite, put on way too much and it had migrated all over the Motor Shaft, onto the 1/4 X 1/4 Key and all over the inside diameter of the Pulley - making the task almost impossible.

Had this pulley been in a location that I was able to apply direct heat to the set screws then more than likely the second one would have loosened as well, but that was not the case here. After getting a new pulley (free of charge from the Factory) I installed it with Blue Locktite and did so sparingly at that making sure only the threads were coated. Now if ever I've got to remove it I should have no problems and I have complete confidence in the Blue strength Locktite because the assembled parts were thoroughly cleaned with Acetone and Alcohol prior to assembly. In all the years I've used Blue Locktote I have never had it open up by itself.

Yes I do occasionally use the Red version when making tools & fixtures that I never ever want to take apart. This has been my experience and is my opinion - YMMV.

[2152hq]

Originally Posted by DWalt

I remember hearing this but never tried it. If you really want to lock two threaded parts together forever, putting a drop of tincture of Iodine on the threads will do that. Does anyone know about that?

That's an old trick, at least in gunsmithing. The Iodine causes the surfaces to rust inside there and lock the parts together.
It does work!

You'll find references to using it in mounting scopes and sights in most 'old' gunsmithing books.,,at least pre WW2 info and earlier.
The less permanent fix was a drop of good old, good for everything Boiled Linseed Oil. It mearly gummed up somewhat and made the screw less likely to back out.
Shellac and the other common finish of the period, oil based Varnish are usually also mentioned for use as a screw lock substance.

Some things haven't really changed much

[BE Mike]

I've only used blue Loctite on gun screws over many decades. I never felt the need for anything else because it always has done the job. I use alcohol to clean the screws and screw holes before applying.

[WR Moore]

I had set screws (wouldn't move) with blue thread locker in aluminum stuff on a shaft. I tried the old trick of using a candle, held below the screw. Worked like a charm. The theory is that besides the limited heat, wax molecules from the candle flame penetrate the joint and act as a lube. Don't particularly care about the theory, just that it worked.

Because of the aluminum flex coupling, didn't want to use a torch. Would have destroyed the flex stuff, might have damaged the aluminum.