Choosing the Best Adhesive for the Job

Whether you are a woodworker, electronics worker, robot builder, craftsmen, DIY ist, tinkerer, hacker or anything like that then at some point in your work you will face the need to glue stuff together. It can be repairing a broken vase or maybe making some artistic craft.

Whatever it may be, you will need adhesives for that. If you go looking, you will find a plethora of adhesives of different brands and different names. They will confuse you into choosing the right one for the job. Shop keepers may try to deceive you into buying the expensive useless ones which would ruin your budget.

Choosing the correct adhesive for your application is very important as it will determine the strength of the bond and its durability. You can save money by choosing the correct adhesive as well.

There are a number of things that factor into the choice of adhesive:

1. Material
2. Surface type
3. Surface Area
4. Clamping time

With these factors in mind i will explain the various types of adhesives out there. Of course i can never cover all of the adhesives are there are so many of them but i will cover the important ones in detail and i will go over the less used ones briefly

I have divided the adhesive intro three categories

1. Basic-These are the ones every house hold should have laying around

• Super Glue
• All Purpose Glue

2. Application Oriented-These are somewhat special and specific for their particular application .Any decent DIY ist should have these in his workplace

• Rubber Glue
• Wood Glue
• Silicone
• Hot Glue
• Epoxy Resin (Slow)
• Epoxy Resin (Fast)

3. Specialty-These are the very special ones which you will only require if you know your adhesives. They wont be easy to find and wont be available in some part of the world.

• Plastic Cyanoacrylate Cement
• Gorrilla Glue

Step 1: Super Glue - Basic

Ahhh yes. Super Glue. One of the most widely used glue on the planet. Every glue company makes them and it is called Super glue or Elfi. It is used where surfaces are in contact. Use only as much as is needed because overflow can get on your hands which is really annoying and difficult to remove. If using on wood then you might need to use a good amount due to porous nature of wood. This is a very cheap and basic adhesive and should be in all households. It is useful for repairs, robot making, crafts, wood work etc.

Materials: Wood, Ceramic, Plastic, Rubber, Metal

Clamping Time: 30 Seconds

Full Cure: 5 Minutes

Surface Type: Full Contact

Surface Area: Variable

Example # 1: If you have a broken china handle you can use super glue on that. Or a broken ornament.

Example # 2: You can use it to join plastics like i used it to make plexiglass project boxes

Step 2: All Purpose Glue - Basic

All purpose glue is also very famous. The most widely used is UHU All Purpose glue. It is a clear liquid adhesive that can bond to a wide range of materials. It is mostly used in crafts and paper work. It is also a basic adhesive. Useful to have laying around for small repairs.

Materials: Wood, Paper, Plastic, Rubber, Metal, Cardboard, Fabric

Clamping Time: 10 Minutes

Full Cure: 2 - 3 Hours

Surface Type: Partial Contact

Surface Area: Medium to Large

Example # 1: If you want to glue cardboard on a wooden frame.

Example # 2: If you want to repair a loose rubber sole on your shoe.

Step 3: Rubber Glue - Application Oriented

Rubber glue is specifically designed for rubber based uses. It comes in yellow liquid or sometimes clear liquids. I am not familiar with its brand names but most brands including UHU have them. They work best on rough surfaces. Apply on both surfaces and allow to dry and then stick together.

Materials: Rubber

Dry Time: 5 Minutes

Clamp Time: 1 hour

Full Cure: 5 -6 Hours

Surface Type: Rough Surface Contact

Surface Area: Medium to Large

Example # 1: Reattaching a rubber sole.

Step 4: Wood Glue - Application Oriented

Wood glue is also a famous glue especially in the wood working community. Its white and in paste form. It is specially designed to bond wood. It penetrates the wood pores and bonds them. It dries clear and works well with good surface area

Materials: Wood

Clamping Time: 12 hours

Full Cure: 1 Day

Surface Type: Full Contact

Surface Area: Large

Example # 1: Making a wooden table, you can use wood glue in the joints. Makes it very long lasting

Step 5: Silicone - Application Oriented

Silicone is less of a adhesive and more of a sealant. It is used to seal glass in windows. It can also be used to glue glass to wood or glass to metal. It forms a rubber and is flexible, water proof and durable. Also used for sealing aluminum windows. Used mainly in home improvement or construction. There are many types and some are designed for high temperature uses such as in a car engine for sealing. It can also join plastic but it only good to use where you can put a good amount

Materials: Wood, Metal, Glass, Plastic

Full Cure: 1 Day

Surface Type: Small Filling

Surface Area: Medium to Large

Example # 1: Filling gaps in between window frame and cement wall.

Example # 2: Making glass aquarium

Example # 3: Making large plexiglass boxes

Step 6: Hot Glue - Application Oriented

Hot glue is also common among the crafts and DIY work. It is basically a hot glue gun in which the glue sticks are melted and applied to the material. It is a gel like when molten and it solidifies to a solid when cooled. It is pretty strong and is best when applied in substantial amount

Materials: Wood, Plastic, Rubber, Metal, Fabric, Paper, Cardboard

Clamping Time: 1 Minute

Full Cure: 5 Minute

Surface Type: Partial Contact

Surface Area: Medium to Large

Example # 1: Gluing together a cardboard box

Example # 2: Gluing stuff for crafts like ribbon flowers on a cloth

Step 7: Epoxy Resin (Slow) - Application Oriented

Epoxies are another family of adhesives and rather strong ones. They come in two separate tubes, one is the resin and the other is the hardener. For use we have to mix them in 1 to 1 ratio. There are two classes of epoxies, slow curing and fast curing. They both come in clear and black color. They are used for filling mostly. Filling gaps and crevices. The slow ones take a day to settle and another to cure fully but once cured properly they are hard to break.

Materials: Wood, Plastic, Metal, Composite Material

Clamp Time: 1 Day

Full Cure: 2 Days

Surface Type: Large filling

Surface Area: Medium to Large

Example # 1: Fixing a hammer head to a plastic handle

Example # 2: Repairing a loose wooden chair by pouring resin into the cracks.

Step 8: Epoxy Resin(Fast) - Application Oriented

This is the second class of resins which are fast curing and they set i a matter of minutes. They are useful when time is of the essence. There are different forms. Clear liquid form as well as black gel form. They also come in two parts and can stick to most materials.

Materials: Wood, Plastic, Metal, Composite Materials

Clamping Time: 15 Minutes

Full Cure: 30 Minutes

Surface Type: Rough contact and small filling

Surface Area: Medium to Large

Example # 1: Gluing a plastic power supply enclosure together.

Example # 2: Fixing a metal conduit on a plastic pipe.

Step 9: Speciality Adhesives

There are many speciality adhesives out there. Most adhesive brands have their own speciality glue.

Gorilla glue is a special glue trademark of the Gorilla Glue Company. It is a polyurethane based expanding adhesive that can stick to more or less anything. It is water proof.

Another speciality adhesive is known as plastic cement which is made up of cyanoacrylate. It basically bonds plastic at a molecular level and the bond becomes seamless. It is very useful to have if you are going to work with plastics.

Step 10: General Gluing Instructions

There are some gluing guidelines that can be very helpful i forming perfect strong bonds. If followed improperly or properly could make the difference between a very weak and a very strong bond no matter how strong of a adhesive you use.

1. First you need to clean the surfaces free from grease, dirt and loose particles which can reduce the effectiveness of the glue.
2. Rough the surfaces for the glues where surface type is mentioned to be rough. Use a fine grit sand paper for that and after sanding clean it. Roughing increases the surface area in contact hence increasing bond strength.
3. Clamping time is the time when you need to hold the materials together or if it is not needed to held then it is the time where you shouldn't disturb the materials at all. Disturbing them early would weaken the strength and durability of the bond.
4. Have control over your eagerness which may be harder than it sounds. Don't use the glued things until fully cured.
5. Sometimes there is a repair in which the joint will have to bear a lot of stress. At that point no glue can do what is required. For example i has to repair a generator's kick start plastic wheel. It had to bear all the repeated stresses of the pulls of the wire. In such repairs it is best to use the composite approach. Go to next step for more details.

Step 11: Composite Approach

This is a repair method that i have devised over the years for breakages where the joint will have to take up a lot of repeated stress and the contact surface area is no where near as much as we need.

Some examples from my experience are a plastic chair which broke. A plastic top piece on a ladder broke. And as i mentioned earlier a generator starting wheel broke.

In this approach first we will have to glue together all the pieces and joints with super glue. Next rough up the areas around the joint line. Then we will have to identify areas of most force which will take some engineering sense. Once identified we will drill holes along the joint for a wire or zip tie. Drill holes according what you will be using. Wide for zip ties and narrow for wire. Use zip ties where space is not a problem and you can accommodate the plastic tie and its head. Where you have limited space then use copper wire and that too according to the space. Large diameter or smaller one according to the area and force.

Once you have drilled and tied up every hole, the super glue will become redundant as all of the load will be beared by the wires or ties. To further strengthen and make durable you can apply a filling adhesive on top of the entire joint covering the holes, the wires and the wire twist or zip tie and tie heads. You can use either fast or slow epoxy for that. If you feel the joint will move a bit and flex then don't use epoxy. Only use epoxy where you are certain that the joint will stay put. For example when i repaired my ladder. I knew there would be so much forces that the zip tie will stretch a bit so i cant use epoxy for that. In those cases you can use hot glue and where there is going to even more stretching, you can use silicone.

This approach if executed properly will result in a durable and strong bond capable of handling a lot of force.

Step 12: Out of Ideas?

Well i like to believe that there is no repair or application that cant be put together. Although adhesives may not be the only option and there are plenty other techniques such as screws, tapes, fasteners etc.

But still if you encounter an application where you have struck out and cant figure out how to get it fixed then hit me up and maybe i can help you. I always like a challenge.

Step 13: Concluding Remarks

Well i hope you found this to be helpful. Honestly if i had this guide back when i started, i would have saved a lot of blunders along the way.

Thanks for viewing.