Contact cement (also called contact adhesive) is a type of neoprene rubber adhesive that forms an instant bond between two surfaces which is nearly permanent.
It is typically used for bonding non-porous materials such as leather, vinyl, glass, metal, rubber, plastic, veneer, plywood, and Formica – where other regular glues do not generally work well.
Once the cement has been applied to both surfaces, it must be allowed to dry before the two surfaces are pressed together. The bond formed by contact cement is extremely strong, making it ideal for applications where a permanent bond is required.
However, it is also difficult to remove once it has cured, so care must be taken to align the two surfaces correctly before the cement is applied.
If you plan to use contact cement anywhere in your home, it’s essential to know more about it and how to use it safely. So, in this article, I will cover the following topics:
- Different types of contact cement
- How do you use it correctly, and what safety tips to keep in mind
- How do you paint over or remove contact cement, and much more…
Are All Contact Cement the Same?
Contact cement is divided into two categories which include water-based and solvent-based.
Solvent-based contact adhesives perform much better than water-based ones because they can stick to even metal, glass, and other smooth surfaces where the latter does not.
That said, keep in mind that both do not stick well to masonry. And solvent-based contact cement can release harmful volatile organic compounds that can also be flammable. So, always use it in a well-ventilated area and avoid using it near open flames.
On the other hand, water-based contact cement is non-toxic and environmentally friendly. So, if you are worried about the health hazards of solvent-based contact cement, then go for one of these.
How to Use Contact Cement – Can it be Painted Over?
Numerous brands are available when it comes to buying contact cement. Some of the most popular ones include Lepage, Weldwood, and DuraPro.
No matter the brand, using it is relatively straightforward. But there are specific steps you need to remember to ensure a successful bond. Here are the general instructions to follow:
Step 1. Prepare the surface you want to bond. This involves cleaning off any dirt, grease, or other foreign substances that could prevent the cement from adhering properly.
Step 2. Apply the cement to both surfaces. You can use a disposable brush, a J roller, or a short-handled scraper for the application of contact cement on both surfaces.
Step 3. Allow the contact cement to air dry and tack up before assembling the two surfaces. This usually takes around 15-20 minutes, but check the manufacturer’s instructions to be sure about the specific contact cement you are using.
Step 4. Press the two surfaces together while applying pressure to ensure a strong bond forms. Applying pressure is essential, without which pressure bubbles can build up between the surfaces.
Step 5. Allow the bond to cure. This usually takes around 24 hours, but again, check the manufacturer’s instructions to be sure.
Once the contact cement has dried completely, you can technically paint over it with any type of paint.
But I think you shouldn’t, really, because the paint can quickly peel off the surface if not done correctly. And also, since the process can be time-consuming, it’s not worth the effort of investing in something only to see it fail soon after.
In my opinion, if you need to paint, you should remove the adhesive, as the cleaned surface will take the paint much better when there is nothing to interfere with the paint.
So, How Do You Remove Contact Cement?
The best way is with a solvent-based adhesive remover. There is a range of different products on the market, but I recommend using one specifically designed for contact cement as it will make the job a lot easier.
- To remove the adhesive, simply apply the remover to the surface and leave it for around 15 minutes.
- Once the time is up, you should be able to scrape off the adhesive quite easily with a putty knife or similar tool.
- If you struggle to remove the adhesive, you can leave the remover on for a little longer or use a heat gun to soften it before scraping it off.
- Once you’ve removed as much adhesive as possible, clean the surface with a solvent-based cleaner to remove any residue.
TIP: If removal isn’t possible, it’s still possible to paint over the surface covered in contact adhesive. Just clean the surface and roughen it slightly using fine-grit sandpaper so the paint can adhere better.
Why Should You Use Contact Cement Over Other Adhesives?
Still wondering why you should use contact cement in the first place when there are so many other options (like Elmer’s glue, Gorilla glue, Super glue, etc.) out there available on the market.
Well, the main reasons are that contact cement is extremely strong and bonds quickly over surfaces where other traditional glues deny working.
Particularly for gluing larger surface areas (like laminating countertops in the kitchen/bathroom, affixing flooring tiles, or bonding heavy materials like wood veneer to cabinets), contact cement works just excellently.
Other regular glues wouldn’t work well on laminates and other non-porous materials because they go on wet. Plus, they will need to get dried after the parts are assembled.
The drying process with these regular glues (on non-porous surfaces) can take longer because it takes longer for moisture to escape or dry out once the parts are joined. The glued parts, therefore, will need clamps to keep them together until the glue dries out completely.
On the other hand, contact cement is already dry on contact. As soon as the solvent evaporates on the surface, the cement works quickly to form a flexible and firmer bond with no residual moisture inside.
You can technically join the two surfaces together without waiting for them to dry and without using any clamping devices. All you need is to:
- Apply the contact cement to both the parts that need to be glued.
- Air-dry the cement for 15 to 20 minutes before assembling the surface or two parts.
But be aware – since this waiting time is way shorter than what you need with other adhesives, you will need to act fast and join the two surfaces together as soon as the cement is air-dried.
The only drawback I can find of contact cement is that it’s relatively more expensive than other types of adhesives.
Also, contact cement is not designed for exterior use and will not hold up to the weather. For outdoor projects, it’s best to use epoxy or resin glues as they are made for weatherproofing. They can be used on surfaces where UV and waterproof protection is required.
What’s the Difference Between Contact Cement and Rubber Cement?
Many times people confuse contact cement with rubber cement.
Although both are grouped as drying adhesive products used in projects such as crafting and handicrafts, they are pretty different in application and results.
Unlike contact cement, rubber cement is an adhesive made from elastic polymers (typically latex). It is mixed with solvents such as acetone, hexane, heptane, or toluene to keep the adhesive in a fluid state that can be used easily.
Once applied, solvents quickly evaporate, and rubber solidifies fast, forming a firm and flexible bond. But in terms of durability, hardness, and strength – contact cement provides a more durable permanent hold.
Contact cement is also not as sticky and offers a relatively higher tensile strength, which simply means it’s capable of holding the glued materials much better.
In contrast, rubber cement tends to provide a temporary hold that is not much durable.
What is contact cement made of?
Contact cement is an adhesive whose most crucial part is its “solids” suspended in the solvent. The higher the solid content in the adhesive, the better it is.
The primary solid in contact cement is polychloroprene, also known as neoprene rubber. Other polymers (rubber-based) can be used in formulating the cement.
When using the adhesive for your project (like adhering veneer to the substrate), it’s important to stir and redistribute the solids to provide better-ridged bonding.
What is the strongest contact cement?
Numerous brands of contact cement are available in the market, and all offer different solids-to-solvent ratios. But as a rule of thumb, the strongest contact cement is the one that has the highest solids-to-solvent ratio.
For example, one product may have a 60:40 ratio while another one might have an 80:20 ratio. So, its good to check the solids-to-solvent ratio of the contact cement you plan to use. Some of the most popular brand names include:
- Devcon contact cement
- Barge all-purpose contact cement
- Lepage heavy-duty contact cement
If the above ones are unavailable, you can check a few others, including Masters, Pliobond, and Yamayo contact cement. They are readily available in a liquid solvent and/or glue tube at stores like Home Depot and Amazon.
The bottom line
Contact cement is an excellent go-to adhesive for projects that require a long-lasting, permanent hold. That said, contact adhesives can be tricky to work with and paint over.
But once you get the hang of them, it’s one of the best adhesives for larger projects that need gluing on non-porous surfaces very fast. Be sure to follow the manufacturer’s instructions carefully to avoid any mishaps.
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Jack Luis is a semi-retired painter who loved painting his clients’ ideas on their walls.
He had worked as a painter for over a decade serving customers in areas such as Charleston, Mount Pleasant, Beaufort, and Georgetown, SC (South Carolina). Today in his free time, he likes to read and write about the newer techniques implemented in his profession. You may read more about him here or get in touch with him here.