LORD Adhesives FAQs
Can I use LORD adhesives when it is below freezing?
Best practices are to use adhesive at room temperature. Typical room temperature cure conditions for adhesives is 65°F-85°F (18°C-29°C). LORD adhesives can be difficult to dispense if the adhesive is stored in a cool area.
Apply LORD adhesives above freezing temperatures. Adhesives in general, cure slower at a cooler temperature, however the end adhesive properties will be like being cured at room temperature. A general rule of thumb is that for every 18°F (or 10°C) drop in temperature the open/cure time will double. An adhesive which normally cures within 24 hours with a 15-minute open time will take approximately 48 hours to cure and have a 30-minute open time when dispensed at 57°F (13°C).
Heat will also affect the cure cycle having the opposite effect than cooler temperatures. For every 18°F (or 10°C) increase in temperature, the open/cure time will be cut in half. Heat will offer some slight advantage in getting higher bond strength.
In general, cure temperatures should not exceed 150°F (65°C) for acrylics, 250°F (121°C) for urethane adhesives and 350°F (176°C) for epoxies.
Does the adhesive have a shelf life or expiration date?
All LORD adhesives have a shelf life which is the amount of time a properly stored and applied product will last and perform per the published properties of the material. Please refer to the Use by Date on the container or refer to the technical data sheet for the shelf life of each adhesive.
Human and Animal Contact
Are there any applications where adhesives should NOT be used?
LORD adhesives are not recommended for assemblies that have direct human or animal contact.
How can I order additional accessories such as mixers for cartridges, dispensing guns, plungers, etc?
LORD authorized distributors can assist with dispensing equipment such as plungers, applicators, and mixers. Contact 877-ASK-LORD or visit www.lord.com for further assistance.
Checklist for Troubleshooting Structural Adhesives
What do I do if my adhesive does not cure?
LORD Structural Adhesives follow specific cure cycles that depend on environmental conditions and application guidelines. Check the following conditions if the adhesive appears soft with no change in color after 24 hours:
- Check the "Use by Date" on the label to ensure the adhesive is within shelf life.
- Check the storage temperature. Exposure to extreme temperatures can degrade the adhesive over time.
- Check that the mix ratio is correct by levelling the plungers and dispensing a small amount of material prior to placing the mix tip on cartridge. Purge the mixer of at least 2-4 inches of material prior to beginning the bonding process.
Bonding Bare Metal
What adhesives do I used to bond bare metals? Will there be galvanic corrosion?
What adhesives do I used to bond bare metals? Will there be galvanic corrosion? When bonding bare metals together, use the acrylic adhesives LORD Maxlok, 800, 400 and 200 series acrylic adhesives. These adhesives are formulated to bond metal and will act as a barrier between them to protect against galvanic corrosion. Only areas of the metal surfaces bonded with the adhesive will be protected from galvanic corrosion.
Compared to traditional fastening methods such as rivets, welds and tapes, LORD Structural Adhesives eliminate the costs associated with metal preparation and finishing operations. LORD adhesives provide greater strength across the bondline of the assembly, environmental protection, and an aesthetically pleasing appearance. Visit www.lord.com for test comparison information.
The adhesive I dispensed yesterday is still tacky on the surface. Is it cured?
LORD acrylic adhesives can exhibit a tacky surface. LORD acrylic adhesives cure from the bottom to the top where the air can compete with the cure process causing surface tack. This is normal for acrylic adhesives and the tacky surface can be removed with alcohol or other organic solvent after full cure. Surface tack is only on the surface, bonded joints are fully cured.
Can I powder coat parts after bonding with LORD adhesives?
LORD, Maxlok, 800 and 400 series acrylic adhesives have excellent heat resistance characteristics up to 400°F (204°C), thus reducing the concern of possible degradation of the cured adhesive during the high heat associated with the powder coating process. (LORD heat resistance data available, 400°F [204°C] up to 90 minutes.)
LORD acrylic adhesives will not degrade at the higher temperatures associated with powder coating, however the hot tear strengths will be very low causing the assembly to possibly sag and slide apart especially if the assemblies are heavy. The lower strength values make it essential that the assembly is properly fixtured or placed to avoid slippage of the bonded pieces.
Spot welds or other type of mechanical fixturing are frequently used in the industry to aid in holding the assembly in place. The area to be bonded can also be masked off prior to powder coating with bonding done after the process.
The integrity of the bond will remain unchanged after powder coating, and greater strength is often seen after exposure to heat once the assembly(s) has been returned to ambient temperature.
Contact 877-ASK-LORD or visit www.lord.com for additional strength charts and graphs.
How to Avoid Bondline Read-Through
How can I avoid bond line read through or surface rippling on thin, glossy or shiny materials?
Read-through is a condition where you can see the footprint of the adhesive through the material. This is caused by shrinkage that results in a pull on the bonded materials. Read-through can occur on surfaces that are high gloss, high polish or have a mirrored finish. Thin gauge metals less than 0.030 inches are more susceptible to read-through.
LORD 810/20GB Low Read-Through (LRT) acrylic adhesive is a flexible adhesive system specifically designed for bonding metals, such as aluminum, galvanized steel and CRS, and engineered plastics, such as PC-ABS and ASA. LORD 810/20GB adhesive delivers fast cure speed and strong bonding with minimal bondline read-through (BLRT).
Bonding to Glass
What adhesive can I use to bond to glass?
LORD adhesives can bond to bare glass with LORD AP-134 Adhesion Enhancer/Surface Modifier. Prime nonporous, smooth, non-metallic substrates such as glass, porcelain, and marble with LORD AP-134. Bond the primed materials to the other substrate using a LORD Acrylic, Urethane or Epoxy adhesive.
Bonding to Chromate Conversion
Can I bond metal which has been treated with chromate conversion coating?
Chromate conversion used to coat metals for corrosion resistance has been found to interfere with the adhesion of some adhesive systems. LORD 200 series acrylic adhesives perform satisfactorily on aluminum with chromate conversion. Testing is recommended.
Cross-Bonding Dissimilar Materials
How do I cross-bond dissimilar materials?
When bonding larger assemblies involving dissimilar materials, such as aluminum or steel to polycarbonate or acrylic, differences may exist in the expansion coefficients of metal and plastic. Adhesives and design need to accommodate the varying rate of thermal expansion.
LORD urethane adhesives can provide flexibility and prevent stress fractures and/or bond failure of the plastic materials. Best practices are to prime the bare metals, scuff the plastic, and bond with a LORD urethane structural adhesive if your testing shows the need for more flexibility.
LORD acrylic adhesives are rigid when cured, provide exceptional structural strength and are particularly formulated for assemblies with a bare metal substrate.
Bonding to Neoprene and Natural Rubbers
Do you have an adhesive to bond neoprene rubber-to-metal?
Bonding to neoprene and natural rubbers can be difficult. Prime elastomers with LORD 7701 Adhesion Enhancer/Surface Modifier. Metal surfaces should be sand blasted or ground to a white finish. LORD epoxy adhesives such as LORD 305, 310, or 320/322 are good choices.
Painting Structural Adhesives
Can I paint over adhesives?
LORD Structural Adhesives are safe to paint after removing squeeze out and full cure. Refer to the technical data sheet for full cure time. After full cure, solvent wipe to remove surface tack and dust prior to painting. Testing is recommended.
Storing LORD Acrylic Adhesives
How do I store LORD acrylic adhesives?
Store LORD acrylic adhesives at temperatures under 80°F (27°C). For maximum shelf life, LORD acrylic adhesives can be refrigerated at temperatures of 40°F-50°F (4°C-10°C). Do not freeze. Do not store on top of shelves or mezzanines. Protect from exposure to direct sunlight. If stored at these cooler temperatures, return the product to room temperature before using. To ensure maximum shelf life, stage only enough adhesive needed for the day’s production.
Storing LORD Urethane Adhesives
How do I store LORD urethane adhesives?
LORD urethane adhesives are moisture sensitive. Cartridges should be left in their Mylar bag with the desiccant until ready for use. Protect partial cartridges from moisture exposure by leaving the nozzle in place to act as a seal after each use. Store LORD Urethane Adhesives between 65°F-85°F (18°C-30°C). Single-component LORD urethane adhesives should be stored between 60°F-80°F (16°C-27°C). The single-component materials will react when exposed to moisture and air. For maximum shelf life after opening bulk containers, replace the lid or cap as quickly as possible and purge with nitrogen.
Storing LORD Epoxy Adhesives
How do I store LORD epoxy adhesives?
Store LORD epoxy adhesives in the original containers between 40°F-80°F (4°C-27°C). If stored at cooler temperatures, return the product to room temperature before using. Full physical properties of epoxy adhesives only develop if the product is dispensed at 65°F (18°C) or above. Epoxy adhesives may be heated to ease dispensing from a cartridge (maximum 150°F (66°C)) as the addition of heat will shorten the work time of the product.
Storing Adhesion Enhancers/Surface Modiﬁers
How do I store LORD adhesion enhancers and surface modifiers?
Store LORD Adhesion Enhancers/Surface Modifiers should in their original containers. When transferring to another container, only transfer the amount needed for the application. Do not return unused material to the original container as this will cause contamination. LORD 7701 cannot be stored in metal containers or be used with metal acid brushes as this will cause the material to precipitate white particles. Keep all LORD adhesion enhancers/surface modifiers, except LORD 459T or 459X, in a cool, dark and dry area. LORD AP-134 can gel if exposed to moisture and should be capped with nitrogen.