Q: Are any Loctite products USDA approved? 

A: The USDA no longer approves adhesives or sealants, so many of our previous approvals have been dropped.

Q: Do Loctite products have Underwriters Laboratories (UL) approval?

A: At this time the following Loctite products have UL approval:

50E,  3640,  515,  83,  3641,  10E,  5083,  3642,  565,  84
3184,  567,  5084,  3144,  587,  90C,  3160,  92, 5293 
3162,  592,  394,  3164,  271, 567,  3172,  5950,  397,  3173
510, 3181     

Q: Are any Loctite pipe sealing products approved by A.G.A. (Australian Gas Association)?

A: 567, 577, 510, 515, 569 and Loctite 55 meet A.G.A. requirement for pipe joint sealing compounds.

Q: Do Loctite products meet military specifications?

A: Yes. There are several military specifications that cover the performance of Loctite products. Consult our Technical Services Department.

Q: I have a Loctite European product. Does Loctite U.S. have an identical equivalent?

A: A list of Loctite Worldwide Products is available through our Technical Services Department.

Q: Whom should I contact if a Loctite product is is involved in a medical emergency (i.e ingestion of, severe reaction to, inhalation of, etc.)?

A: Consult Section 4 of the Material Safety Data Sheet. In case of a medical emergency, please contact the Rocky Mountain Poison Control Center at 303-592-1711. They will accept collect calls.

Q: Are Loctite products toxic?

A: Generally, most Loctite products have minimal toxicity. They are nonpoisonous and generally are classified as mild skin sensitizers. Occasionally, people with sensitive skin will show slight irritation after long term exposure to Loctite products. Our primers and activators contain solvents, which can affect employee's health and should be well ventilated. If you have additional questions about health and safety issues please contact our Technical Department

Q: What will happen if I mix Loctite product X with Loctite product Y?

A: We do not suggest mixing Loctite products. A wide range of products are available to control strength, cure speed, and viscosity. For large applications, we can modify our products to a customer's needs. If a customer is considering mixing different products, he/she should contact his/her sales specialist for advice on whether another Loctite product would fit the requirements.

Q: Are Loctite products compatible with oxygen?

A: Loctite does not have any products compatible with oxygen or strong oxidizers such as chlorine gas.

Q: What solvents can I use to remove liquid Loctite materials?

A: Most organic solvents are effective in removing anaerobic and cyanoacrylate adhesives. Chlorinated solvents are most commonly used. Dry MEK and acetone are used on applications using instant adhesives.

Q: How can I remove a fastener that is "permanently" locked in?

A: The application of heat is needed to remove a fastener that can't be removed with a hand tool. Temperatures of 325F and above is needed to break down a standard anaerobic, 500F for high temperature Anaerobics. A heat gun or propane torch is commonly used to do this process, and careful disassembly should occur while parts are still hot. Once apart, and cooled, use methylene chloride (Chisel #79040) to remove cured excess material. Always wipe down the fasteners with clean up solvent to remove the wax film that Chisel leaves on the surface.

Q: Will my bonded parts stay together 5, 10, 20 years from now?

A: Testing long term durability is a difficult matter and there are many methods of accelerating bond life testing. Some of these are exposure to elevated temperature, heat fatigue, and humidity exposure. The only way to be absolutely sure that the parts will stay together for a ten-year period is to age parts over that extended period of time. The best way to estimate bond aging would be to compare new products to known quantities and determine ratios of performance in elevated aging tests. The longer and more critical the bond life, the more important the testing is.

Q: What can I do about the vapors and odors given off by a Loctite cyanoacrylate?

A: The vapors of Cyanoacrylates are irritating and workers should not be exposed to them for long periods of time. In many cases the use of our "Low Odor" "Low Bloom" products can be used to control the irritating odor.

Q: I'm using a cyanoacrylate adhesive and I've got a white haze around my bond area. Is it harmful? How can I remove it and prevent it from occurring again?

A: This phenomenon is known as "blooming" or "frosting". This occurs with Cyanoacrylates during their cure cycle. Blooming usually occurs in the summertime when humidity is at its peak. It can also occur when a customer uses an excessive amount of accelerator, which causes a violent curing reaction with our products. In some cases, the end user doesn't allow the product to fully cure before he/she places the assembly in an enclosed area. This prevents the vapors from fully dissipating.

Solutions:

• Use a low odor low bloom product. They are formulated to help lessen blooming and hazing. 
• Apply cross ventilation from fans to circulate the air so the vapors don't settle on the bonded assembly. 
• Lower the humidity. The use of a dehumidifier is a good method for keeping the humidity at a constant rate. Suggested humidity is 40-50% 
• Apply less adhesive and/or less activator.

Removal:

• Clean up procedures depend on the substrates bonded. In most cases, the use of XNMS Clean Up Solvent, or acetone can be used to remove "blooming" or "frosting".

Q: How long does it take for an anaerobic adhesive to dry?

A: Anaerobic adhesives do not contain solvents, which must dry. For an anaerobic adhesive to cure, it must be in contact with active metal ions and contact with oxygen eliminated. Outside of a bonded joint, anaerobic materials will not completely cure. Inside the joint, cure rates can be controlled by changing product and primer. Heat can be used to accelerate cure rate.

Q: What are materials that are considered "active" and "inactive"?

A: The list is as follows:

ACTIVE                                                        INACTIVE
Iron                                                              Plated Parts
Plain Steel                                                 Anodized Aluminum
Nickel                                                         Titanium
Copper                                                       Stainless Steel
Manganese                                               Galvanized Steel
Kovar                                                          Zinc
Commercial Aluminum                          Pure Aluminum
(with copper content e.g. 6061)            Cadmium
Brass                                                         Magnesium
Monel                                                         Magnetite Steel
Bronze                                                        Iconel
                                                                    Silver
                                                                    Gold
                                                                    Natural or Chemical Black Oxide

Q: Why does Loctite only fill half of their anaerobic 50-ml and 250 ml bottles?

A: Actually, there is exactly 50 ml and 250-ml adhesive in each package. We fill bottles halfway because air is needed in the package to prevent our Anaerobics from solidifying. Our 50-ml and 250 ml bottles also allow our Anaerobics to breathe by allowing air to permeate through the bottles.

Q: What do colors mean?

A: Many times Loctite anaerobic materials are called " the red or the blue stuff". With threadlockers, colors designate strength. Generally red means high strength and blue means moderate strength, and purple is low strength. Other colors do indicate strengths in relative areas.

Q: Should I use a primer for curing Loctite Anaerobics?

A: Almost all Loctite products will cure on metal surfaces without a primer. Therefore, primers are recommended for use on non-metallic surfaces with Anaerobics to achieve a practical cure speed.

Q: For threadlocking, most strength data is on 3/8"-16 fasteners. My fasteners are larger/smaller. How strong will the product be on my fasteners?

A: This data is available through Technical Information Services on strength variations for fasteners of different sizes. There are many other factors affecting strength, such as tightening torque, finish on the fastener, thread engagement length, and the type of thread which will affect product performance, and therefore it is difficult to publish data on many common fasteners and impossible to prepare data on all fasteners.

Q: Will Loctite products attack thermoplastics?

A: Loctite anaerobic products can attack some thermoplastics. Generally, they will not attack thermoset plastics. To avoid stress cracking or attacking of thermoplastics, a superbonder or cyanoacrylate can usually prevent this problem. Cure is so fast that it generally will exhibit no serious stress cracking. Refer to the Loctite Plastic Bonding Guide for suggestions on the best Loctite material to bond different plastic substrates.

Q: How long do I have to wait before I put my bonded parts into service?

A: In many cases, parts can be put into service as soon as they reach the end of the assembly line. Loctite Threadlocking products show evidence of cure within 15-20 minutes and can resist vibration within an hour. Loctite speedbonders generally have a 20% cure within a few minutes, and 80% cure within 2 hours. Instant adhesives are often put into service within seconds.

Q: Can I cure the filet (adhesive outside the joint)?

A: Yes. Loctite anaerobic adhesives do not cure in contact with air and therefore, exposure to high temperatures (300 F or higher) must be used to properly cure fillets.

Q: What are Loctite products compatible with?

A: Loctite anaerobic products are resistant to a wide range of fluids, gasses, and environments. Data can be obtained from Loctite's "Fluid Compatibility Chart" (LT-836B).

Q: What kind of surface preparation do we need for the use of Loctite products?

A: For Loctite threadlocking and many sealing compounds, as received surfaces with thin films of oil are acceptable. Only the removal of heavy grease or contamination is necessary to achieve adequate adhesive performance. For Loctite structural adhesives and instant adhesives, testing must be run to determine acceptable surface treatment. Generally, the end user should try to use the least complicated surface treatment required. An outline for testing surface treatment is available in Loctite Technical Data Sheets.

Q: My parts have to be plated. Is it better to plate the parts before or after assembly with a Loctite product?

A: Plating on the surface of parts will affect the strength and cure rate of Loctite products. Generally, products will cure more slowly and have lower strength on plated parts. In most cases, however, this is more than adequate. Assembly of plated parts often eliminates any requirements for degreasing or removal of contamination, since parts come from plating operation with very clean surfaces. Thus in most cases, parts are plated before assembly.
In the few instances where plating is attempted after assembly, Loctite products will generally stand up well to the temperatures and fluids found in the plating operation. Some products do not stand up well to plating operations, and therefore, testing should be conducted before attempting this in production.

Q: Do primers affect the strength of Loctite products?

A: Locquic primers are not "primers" in the sense that they increase strength like paint primers. Changes in a cure speed and percent cure will result from the use of primers and, therefore, primers may increase or decrease the strength of products slightly. Specific data can be found in Technical Data Sheets, and testing is recommended on the parts to be assembled.

Q: How long will primers stay on the surfaces of my parts?

A: The "on part life" of each primer varies. Primer N has an on part life of one month and Primer T has an on part life of one week. Other Locquic primers and activators have shorter on part life ranging from 30 minutes to two hours. Refer to the Technical Data Sheet for specific on part information.

Q: Should I prime both surfaces?

A: In most cases, this is not necessary. Generally, one surface can be primed and adhesive applied either to the primed or unprimed surface. Situations requiring priming of both surfaces generally arise when very rapid cure times are desired or when bond line gaps of .015 or more exist.

Q: Will refrigeration improve the shelf life of Loctite products?

A: The shelf life of Loctite Instant Adhesives will be improved by refrigeration prior to being opened. Refrigeration will have minimal effect on the shelf life of our anaerobic adhesives. Refer to the package labeling for proper storage conditions.

Q: What is the shelf life of Loctite products?

A: Most Loctite products are guaranteed to perform within specification for a period of one year from date of shipment. For specific information on the shelf life of the product, please contact our Customer Service Department.

Q: How much adhesive do I need?

A: Only enough to fill the bondline. Use of excess material will be wasteful and can lead to migration, causing clean up problems. Automatic application equipment can control the use of the product on-line. Technical Information Services can supply "usage" estimates for various applications.

Q: How many drops per tube, bottle, liter, pound, etc.?

A: This is dependent upon the viscosity of the liquid. An Application Engineer Publication (AEP #10) has been done to aid in questions regarding adhesive usage information. Contact Technical Information Services to learn more about adhesive usage.

Q: How can I speed the cure rate of a silicone?

A: Loctite silicone sealers cure upon contact with moisture in the air. The cure progresses inward from the surface. Sections up to 1/8' thick become a rubbery solid in about 24 hours. Curing time increases with the thickness of the sealant section. The addition of moisture in the form of humidity will speed the cure rate. The application of heat alone may drive off moisture and prolong the cure time.

Q: Can I paint over cured Loctite silicones?

A: For best results, any painting should be completed before applying a silicone. Although most silicones will bond to most painted surfaces, paint will not adhere to silicone rubber.

Q: Are Loctite products corrosive?

A: Generally, Loctite products can be considered to be non-corrosive. Our Superflex Silicones (acetoxy cure) have been known to cause minor corrosion on electronic components. The use of our Ultra Series (methoxy based or oxime based) silicones are considered to be low or non corrosive.

Q: Can Loctite products be applied underwater?

A: Yes. Use Fix Master underwater repair epoxy. Refer to the Adhesive Sourcebook for more information. (page 81)

Q: Can Loctite products be heat cured?

A: Yes. The use of heat will accelerate the cure of most Loctite products and may increase the strength of structural adhesives. Combinations of heat and primer can also be used to develop optimum cure speed. Instant adhesives should not be heat cured.

Q: Does Loctite have a product to bond polyethylene, polypropylene, Viton or Teflon?

A: In most cases, surfaces such as Teflon, polyethylene and polypropylene are not easily bonded and require a surface treatment to achieve any desirable bond strengths. To obtain further information on bonding plastics, refer to the Plastics Bonding Guide.

Q: What is Loctite's highest strength product?

A: This depends on the type of strength desired. Loctite has adhesives with tensile strengths of 8,000 psi or higher. Other adhesives with lower tensile strength may have superior impact and peel strength. Contact Technical Information Services to suggest the correct product based on your strength requirements.

Q: How can I choose between Speedbonders and Instant Adhesives?

A: Each of these products are capable of bonding many different materials with considerable speed. The Loctite salesperson and Technical Information Services staff can help you choose by qualifying specific strength areas and environmental conditions. In many cases, the final choice will be based on convenience, bond line, bond durability and adhesive cost.

Q: Does Loctite have flexible products?

A: Loctite has a wide variety of flexible adhesive products including, silicones, urethanes, hot melts, epoxies, and light cure materials. To best help choose a flexible product, the requirements for the assembled parts should be defined to determine the nature of flexibility required.

Q: Can Loctite change strength, viscosity or other properties to fit our application?

A: Yes. Standard Loctite products are available in many ranges of strength and viscosity and these fulfill most requirements. Occasionally, we find that major applications may require a modified viscosity or strength range. If necessary, Loctite products can be modified to create a "special" product for such applications.

Q: Does Loctite make conductive adhesives?

A: Yes. Loctite has information on both thermally and electrically conductive materials. Refer to the Electronics section of the Adhesive Sourcebook for appropriate part numbers.

Q: How can I stop Loctite products from running out of the joint?

A: The most important aspect of this problem is using the proper viscosity and application technique. Minimal amounts in the proper place will minimize or eliminate migration. Thixotropic adhesives will also eliminate migration.

Q: Are Loctite products resistant to radiation exposure?

A: Customer and in-house testing indicates that radiation exposure within certain limits will not significantly affect the strength and bond life of Loctite anaerobic products.

Q: What happens to Loctite products at cryogenic temperatures?

A: Exposure to cryogenic temperatures will cause most materials, including Loctite products to become very brittle. Therefore, we can expect assemblies to be less shock resistant at lower temperatures. In the case of threadlocking, the assembly will still be more shock resistant than an assembly without a Loctite product. In other applications, the products can be made to perform at cryogenic temperatures, but designs must be such that exposure to the low temperature does not cause parts to shift and destroy the bond. Technical Service personnel should be consulted for guidance in these matters.