Frequently Asked Questions by Adhesive Type
Our adhesive experts at Gluegun.com receive several questions each week on adhesives, applicators, specific applications and much more! We love learning about your unique projects and helping you select the correct tools for the job. In this article we've combined our most frequently asked questions, broken down by adhesive type! The Gluegun.com team hand-selected our featured hot glue sticks, polyurethane PUR hot melt, cyanoacrylate super glue and silicone spray adhesive, cleaners and lubricants.
Hot melts are thermoplastic (can re-melt when heated) adhesives which offer a fast cure and easy dispensing using a hot melt stick gun. They excel at bonding porous materials such as paper, cardboard, wood, as well as some plastics. They cannot be expected to offer performance (adhesion and environmental resistance) compared to other adhesives which offer chemical adhesion to substrates such as epoxies, MMA's, PUR's or silicones.
My hot melt doesn't bond very well, I thought it should be better.
If a traditional hot melt does not perform well enough, specifically in regards to adhesion or long-term weather resistance, try using a PUR hot melt or other structural adhesive since those types of products provide robust chemical adhesion to surfaces.
How do I know which size hot glue stick to use?
This is a very common question about hot glue sticks. To find the answer, first we need to start with the glue gun. Glue guns will only take one size of hot glue stick so you need to be sure to match them correctly. The most common size of hot glue stick is 1/2" for most applications. Craft glue sticks are 5/16" (sometimes called mini hot glue sticks).
With so many choices, how do I know which hot glue stick is best for my application?
There are a lot of different brands and formulations of hot glue sticks and sometimes it can feel overwhelming. Gluegun.com has created a great filtering system so you can narrow down by what you're bonding, application, special features, etc. You can also contact one of our adhesive experts for a personalized recommendation or check out our unique hot glue stick finder as well.
What is the difference between low temperature hot glue sticks and standard temperature (also called high temperature) hot glue sticks?
Low temperature hot glue sticks typically have a melting point between 250-300 degrees F. These sticks require a low temperature or variable temperature glue gun to dispense correctly. High temperature hot glue sticks need to be dispensed between 350-400F and must be run through a high temperature or variable temperature hot glue gun. Trying to run a high temperature hot glue stick through a low temperature hot glue gun (or vice versa) can cause serious damage to your glue gun and make it so the adhesive does not perform properly.
Do hot glue sticks give a permanent bond?
Hot glue sticks can create a bond strong enough for a huge range of applications and substrates but they are not considered "structural adhesives". The closest thing to a structural bond with an adhesive that performs and dispenses like hot melt would be Polyurethane PUR Adhesives.
Featured Glue Stick Adhesives
Cyanoacrylate Super Glue
Cyanoacrylate adhesives, sometimes referred to as super glues, are one-part fast cure, moisture curing products. Use when fast cure is required, or when bonding lightweight assemblies. Capable of very high bond strengths but not the most resistant to environmental conditions such as outdoor exposure. Cyanoacrylates cure within seconds when pressed into a thin film between two surfaces.
Why is my CA curing slowly or seemingly not curing at all?
Usually in winter months, the relative humidity is low enough to cause noticeably slower cure with CA's compared to summer months. A CA is moisture curing. It uses the moisture on the parts being bonded as the catalyst for cure. Utilizing a humidifier in the area will introduce enough moisture into the air to help the product cure faster.
What is super glue viscosity?
The viscosity of a cyanoacrylate super glue refers to the thickness of the adhesive and is usually referenced in centipoise (cps). Thinner super glues are good for getting into tight places and covering substrates, while thicker super glues can help with gap filling. Below is a brief reference for viscosity:
- 1/5 cps: like water
- 50-100 cps: like motor oil
- 2,500 cps: like honey
- 50,000 cps: like ketchup
What is toughened super glue?
Toughened super glue, sometimes called rubber toughened, is formulated to offer impact and shock resistance. Toughened cyanoacrylates typically have a more flexible bond and hold up under high and low temperatures. They are often better for outdoor conditions when exposed to a lot of moisture or humidity.
What are surface insensitive (SI) cyanoacrylate super glues?
Surface insensitive cyanoacrylates are formulated for extremely fast curing, even by super glue standards. They also bond to a wide range of surfaces including wood, plastics, metals and glass. Surface insensitive super glue adhesives are one of our favorite choices for general purpose use because of their set speed, strength and versatility.
Check out the ASI SI Gel Super Glue for a great all-around performer.
What are cyanoacrylate super glue accelerators?
Cyanoacrylate accelerators can be applied on substrates before super glue is applied, or in some cases afterwards, to make the adhesive cure faster. These are particularly useful for substrates that are hard to hold in place, high volume applications or with cyanoacrylates that have slower set times (like toughened super glues). We have a complete line of adhesive accelerators to help speed up your next super glue bonding application.
Featured Cyanoacrylate Adhesives
Spray Adhesives, Cleaners and Lubricants
Spray adhesives are offered in a range of strengths, offering a selection of adhesion levels customized for particular projects. Spray adhesives are ideal for a wide range of applications. They are commonly used fr crafts and art projects, repairing furniture and appliances, and mending leather or fabric, among other purposes.
What industries are spray adhesives currently used in?
Spray adhesives are used in thousands of applications around the world. Common applications for spray adhesives include:
- Automotive and Marine Manufacturing
- Construction and Housing
- Furniture and Upholstery Assembly
- HVAC Applications
- Packaging and Crating
- Screen Printing
- Plastic Molding (silicone sprays for mold release)
When are spray adhesives the best option?
Spray adhesives are used in a wide range of applications and industries. They can be a great option in applications that require bonding a wide surface area. Also, spray adhesives are very easy to dispense, giving them an advantage over two-part adhesives or other glues that require expensive dispensing equipment. Because spray adhesives do not need to be heated, they are also very good for sensitive substrates like fabric, foam, wood, etc.
Do you offer low VOC aerosol spray adhesives?
Yes, Gluegun.com has recently introduced a complete line of low VOC aerosol spray adhesives. Below is a quick rundown of low VOC products we currently carry. All of our low VOC spray adhesives are CA and OTC compliant.
- Camie 500 - General Purpose Spray Adhesive
- Camie 513 Fast Tack Upholstery Adhesive
- Camie High Strength, Fast Tack Spray Adhesive
- Camie 573 - High Performance Spray Adhesive
- Camie 575 Screen Printers Flash Cure Spray Adhesive
Featured Spray Products
Polyurethane PUR Hot Melt Adhesives
PUR's (Polyurethane Reactive) hot melts are moisture cure urethanes that offer fast fixture strength and are applied like a hot melt at temps between 250F and 280F. Use when fast fixture time is required but performance must be better than a traditional hot melt resulting in a permanent bond. Woodworking and product assembly are the prime uses. A significant amount of strength is achieved within 24 hours, but full strength occurs after 7 days.
The parts I bonded with my PUR came apart far too easily when I tested them.
PUR's provide chemical adhesion but since they are moisture cure products, the cure is not immediate. Even though the PUR cools down to room temperature quickly and holds the parts together, the cure cycle is just beginning at that point, and adhesion and bond strength continue to build over time. A significant amount of bond strength is realized after 24 hours, but ultimate strength is achieved many days later (up to one week).
Are PUR hot melts stronger than traditional hot melts?
Polyurethane hot melts usually provide a stronger bond than a traditional hot melt. PUR hot melts form a strong initial bond that continues to strengthen as the adhesive reacts with moisture in the air. Providing a permanent, moisture-cured bond. As the adhesive cures it undergoes a chemical change, making PUR an excellent choice for woodworking, outdoor applications and product assembly.
How should I store my PUR adhesives?
If unopened, the adhesive should be stored in a foil pouch in a cool, dry location. Do not expose the PUR tube to rain or moisture. Before shutting down for the day, extrude a one-inch bead of adhesive to ensure that air has been extracted for the tube. CAUTION: Do not touch the applicator heat cylinder or cartridge when at maximum temperature. Always wear protective gloves.
Featured PUR Adhesives
When it comes to working with adhesives and sealants, there are a few things you should know. While they are generally very easy to use, it is important to choose the correct applicator and adhesive for the job. At Gluegun.com we provide you with an excellent customer support team. Our adhesive experts are here for you, through every step of your application, to make the process easier through both our products, and people! Speak to an industry specialist today 1-855-437-7700
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