Loctite: By The Numbers
More Than Just Thread-Lockers
Various Loctite products Greg keeps handy on his bench. Each one does a specific job so knowing their features
helps you to select the correct product. The Henkel website explains them all clearly.
Loctite is an adhesive often used in the gunsmith trade. It can secure threads to various degrees of permanence, so it can be critical to select the formula that works best for your application. A sight adjustment going awry during a match is one thing. But an essential pin holding a trigger in place failing during a defensive shooting could be life-threatening. Assuring you’re using the right “locking” product could honestly be the difference between life and death.
Most often, Loctite or a similar product is used to set a screw in position after an adjustment or installation is made. In part like a sight or trigger mechanism it prevents a screw or pin from moving during vibration and stress caused by shooting and running the action.
Even lowly grip screws prone to backing out can benefit from one of the low-adhesion thread lockers, like #222 “Purple” Loctite. It will hold the screw in place easily in this situation, yet will release with a bit of torque from a screwdriver.
Some of the basic Loctite thread-lockers you’d commonly find on a gunsmith’s bench.
Photo: Henkel Adhesives
Color Meanings
I like to break it down into colors, since different Loctite products are color-coded. For instance, as we said, “Purple” (#222) is low strength and can also be used on metals like aluminum or brass. It’s handy for eyeglass screws, sights, wristwatches and any light-duty screw less than 1/4″ in diameter.
Loctite #242 or “Blue” comes in many forms (stick and tape too) but gunsmiths will likely use the liquid form. Its “medium” strength means it’s great for stock bolts, sights, side-plate screws or anywhere you want something to stay put. It can be removed fairly easily by the tool that tightened it to begin with.
Loctite #277 or “Red” is higher strength. Think trigger over-travel screws, action parts needing to be secured in place once set or a cylinder screw. Some like to use it on 1911 grip bushings to keep them from turning out when the grip screws are removed.
Loctite #243 is a bit “brawnier” than standard blue #242 and is also more oil resistant.
This one is marked in German because it was bought online from Europe, but the number is always the same.
Tips
To ensure Loctite really works I first degrease the parts to be set. A squirt of break cleaner to clean the parts, then I use a small torch or a butane BBQ lighter to sweat off any cleaner. The Loctite should be used sparingly, just a dab is enough. They even offer a gel stick applicator which won’t spill. Now screw the parts together with light tension, the adhesive will work without over tightening.
In the event you want to remove a screw I use the same method for most screws, with or without Loctite. Using the proper sized “gunsmith” screwdriver, Allen key or Torx bit, try to lightly turn the screw. If I feel resistance, I add a little muscle. But if it still won’t move I apply heat to the screw.
You can use either a small handheld butane torch or a soldering iron placed on the screw head. The heat will soften the Loctite, allowing it to break free without damaging the head. The key here is feeling the screw slowly break free and not buggering the fastener.
When in doubt, a drop of Loctite will never hurt and might just keep a gun running. If you’re a gunsmith, this also translates into a happy customer!
For more info:
www.henkel-adhesives.com
