Epoxy Cement Guide – Applications and Concrete Repair with Epoxy

• Bonding and repair of steel plating, tiles, and more.
• Provides reinforcement repairs
• Prevents corrosion
• Offers water-resistant properties
• Helps to smooth out surfaces

The difference comes in composition, epoxy cement contains more of a powder-like filler while the epoxy mortar is a sand-like filler.

You also get an epoxy putty, which also contains a filler, but provides a thicker application and is used as a space-filling putty-like adhesive. It is not the same as epoxy or mortar cement.

Guide to epoxy cement repairs

Epoxy cement floor repairs for a sidewalk

When the sidewalk has a crack that is quite wide and not just a thin line, it must first be enlarged by using a cold chisel and a hammer. This process involves undercutting, where the crack should be made wider at the bottom than at the top. Once this is done, take a wire brush to remove any residue and hose the area down before moving on to the next step.

You can then apply an acrylic resin adhesive and leave this to dry. Next, apply a pre-mixed concrete patch onto the undercut space. Make sure to smooth out the mixture by using a trowel. While the cement is still wet, cover it up until it dries out and then leave a plastic sheet over the area for at least five days.

Epoxy cement floor repairs for your driveway

Follow the same steps as for the sidewalk, but since this surface experiences more weight, you should repair it with a little more strength. In this case, a gravel composition is best and can be done by combining sand, cement, and gravel.

Undercut the damaged area and apply cement repair adhesive. Follow the same steps as for the sidewalk repairs and leave covered for at least 5 days before driving on it. Add epoxy for a stronger and more durable Epoxy cement floor.

Concrete crack repair epoxy

Epoxy cement floor repairs for hairline cracks. Begin the process by combining water and cement to form a paste. Moisten the crack with water about 4 hours in advance, then apply the paste. The area should be dry before applying the cement paste, then using a pointed trowel cover the crack with the paste. You can also use a concrete crack repair epoxy, which is a Two-Part Epoxy Adhesive Paste.

Use a little weight in the application to ensure the paste goes into the crack. Next, even out the surface and leave to dry for around 2 hours. Then cover with a plastic sheet for five days, every day lift the sheet and sprinkle a little water over the area. Once the five days are done, you can remove the sheeting.

Image: bhakpong – stock.adobe.com

Epoxy cement versus Urethane Cement

The two main types to choose from include urethane cement and epoxy cement. In many cases, the decision is easy, you can use both. Both these types of floor coatings each have their own benefits, let us have a look at these separately.

Urethane Cement

This type of floor coating makes use of liquids or polymer urethane combined with normal cement. This mixture then becomes solid. The bond formed between the cement and liquids forms a smooth coating and is also heat and water-resistant.

The urethane cement floor is seamless and, therefore, prevents any chemicals or bacteria from penetrating any seams or cracks. This makes it unaffected by chemicals, which is ideal in an industrial environment.

Epoxy Cement

Using Concrete repair epoxy is another great way for coating concrete floors. The epoxy consists of two ingredients, the resin, and hardener. The epoxy system can easily be instantly and safely applied, making the floor more durable and water-resistant. Your worn-out concrete floor is transformed and will look even better than before.

An added benefit is that epoxy can come in different colors, you can easily include logos or different areas. Epoxy is useful in places such as:

• Epoxy Garage Floor
• Epoxy Concrete Floor
• Hospitals
• Warehouses
• Industrial environments

Can you use both?

Since urethane creates a poor bond with the cement, it would benefit the coating process if epoxy is added. The method of coating will involve first applying an epoxy base coat and then a urethane topcoat. Once this is done, the newly coated floor will last much longer than the original concrete floor. It will offer amazing durability and scratch resistance amongst its other benefits.

Image: bhakpong – stock.adobe.com

The best floor coating is, therefore, the combination of urethane and epoxy. This type of flooring provides protection against heat, moisture, and chemicals, and offers great strength or durability.

Another factor of water-based polyurethane floor finishes is that they are also rather expensive to use especially since many coats need to be applied onto the floor or wooden surface.

However, it is best to ask a professional about your specific needs when it comes to floor coatings, as this mixture may not be the best way to go for all projects. Thankfully, the urethane and epoxy combinations can be customized.

• Always start by injecting the epoxy at its lowest pressure setting, and slowly increase this as you progress
• Fill wide cracks slowly, and take some time while injecting the epoxy. This is to make sure that the epoxy is filling the crack completely
• The bigger the crack, the more injection pressure is needed
• Always be aware of epoxy backflow. This could be caused by debris blocking up the flow, or the crack not being continuous
• When you remove the top seal of the epoxy, you can use a scraper or chisel to do this
• Make sure that the epoxy is fully set and sealed before removing the ports. This can take up to 48 hours
• Sometimes the top seal may have a small leak present. This can be fixed up with a crayon
• When working with narrow cracks, you can start by adding a bit of caulk on the side of the crack. This helps to minimize epoxy waste, and it makes the filling and adhesion more efficient
• Epoxy injection isn’t suitable for all cracks – especially very wide ones. Always make sure that the crack is suitable for epoxy repair before you get the crack repair kit.

Tips and Tricks for Concrete Epoxy Repair

Using concrete crack repair epoxy can be a simple process, but it also requires the right knowledge and skills. Before starting to fix your concrete crack, follow these tips and tricks for an easier process.

Surface Preparation is Essential

In order to provide the best long-term strength and success for the epoxy crack filler, surface preparation is vital. Make sure that the concrete surface is properly cleaned, with no residue, dust, or dirt being left behind. This can be done with gentle or aggressive measures, as long as the structure of the concrete is not affected.

If you take a very abrasive method for cleaning, it might leave a layer of dust over the crack. This can be efficiently cleaned off by blasting a pressure sprayer. A shotblast can be the best method for preparing protective coatings. This helps to clean the surface, open the pores, and slightly roughen the surface. It is essential that any surface contaminants, release agents, oils, or curing compounds are completely removed. An abrasive removal can achieve this.

Pressure washing is often a good method to use. Make sure that the pressure cleaner has at leat 5000 PSI.

Since the Loctite Professional Liquid Superglue has only one disadvantage, but several advantages, it is the clear winner for us in our superglue test.

Work Safely

When working with concrete, epoxy, and abrasive cleaning methods, you will need to make sure that you take proper safety precautions. There can be dangerous chemicals involved when using epoxy concrete filler, so you need to make sure to wear the appropriate protective gear. This includes gloves, goggles, and possibly a face mask. Try to also wear long sleeves and long pants. If possible, it is best to work in a space that has maximum air ventilation.

Cleaning Up

After work, you will need to clean up the epoxy from your tools and workspace. A good product for this would be MEK or acetone. For very small amounts of mess, you could even use water with dishwashing soap to clean up – this works well on tools. Liquid detergent/concentrated soap is cheaper and safer to use than solvents, and this is always a better choice for cleaning your skin as well.

Hammering Concrete

Before fixing the concrete crack by filling it with epoxy, you first need to establish whether this is the right method to take. You can find this out by using a sounding hammer to assess the concrete that needs repairs.

Using Heat

The curing time of the epoxy is affected by the temperature. The rate of reaction can change at intervals of 2 for every change of 18 degrees Fahrenheit. You can add a gentle heat supply to the area if the epoxy is curing too slowly.

This can be done by using a heat gun, pre-heating the epoxy before use, baseboard heaters, or using warming blankets. Whatever method you choose, try not to exceed 300 degrees Fahrenheit when heating the area. Epoxy also releases its own heat when it cures, so thicker areas will actually cure faster. It’s also important to note that very hot summer temperatures may also limit the lifespan of the epoxy. This can be helped by cooling down the individual parts before use to extend their life.

Thinning the Epoxy

A way to thin out epoxy that is too thick would be to preheat the components before you mix them together. You can store the epoxy in heated rooms, or even add a lightbulb to the injection pump to keep the epoxy warmer in the reservoir. Just remember that the curing time of the epoxy once mixed will also be affected by temperature changes.

Shrinking Polymers

When the two epoxy parts are mixed together, most of the polymers will end up shrinking when they cure. The newly formed polymers are smaller than the unreacted components. This means that shrinkage should always be considered before applying the epoxy to the crack. Of course, you also need to understand how thick you can make the application before putting the concrete under internal distress. Some methods for helping this include multiple lift installations, using low modulus or exotherm resins, or using aggregate filled epoxy systems.

Moving Polymers

Not only do the epoxy polymers shrink when they cure, but they can also expand. Concrete repair polymers generally have a greater rate of expansion than concrete. The specifics of this will vary depending on the manufacturer or product used, but they will always expand and contract more than the concrete does. This is an important consideration when working with a large crack.

Understand the Width of the Crack

You need to properly understand the width and depth of the crack before doing an injection repair. This can be done by using a plastic crack card or a portable crack scope. This is necessary for understanding the amount of epoxy required. Smaller repair jobs are generally more wasteful, as the amount of materials needed for flushing the gun can be more than the amount used to fill the crack. Always consider this before starting the job.

Keeping the Epoxy

Once you have finished the application process, you may have leftover epoxy. Of course, only unmixed portions can be considered leftovers because they won’t cure. This can still be stored for a long time, and used again when needed. Place any excess epoxy components into airtight containers, and keep them stored away until you might need them again. Water-sensitive substances may not be able to keep for as long though. This can include things like polyurethane.

Getting the Right Appearance

Getting the structure of the concrete fixed is not the only consideration. You may also have a very specific concrete aesthetic that you will need to maintain. How can you get the original smooth surface of the concrete back after you have applied the sealant? A technique called sacking can be used. This is when you wet the surface of the concrete and then hit it with a sack containing a fine amount of the same color concrete. You can also paint over a fine cement-based slurry with a brush.

Cold Weather Conditions

Sometimes concrete cracks will contain frozen water, which is really irritating. Another thing about working in cold weather conditions is that the epoxy will take much longer to cure. This means that the injection must be done very slowly, and the seal must be left on longer to cure. A coating should have the right dew point – something that is very important when working in cold weather conditions. If invisible dew is trapped underneath the epoxy, it can lead to a major problem.

Epoxy usually goes dormant below 35 to 40 degrees Fahrenheit, and it will continue to cure when the temperature increases. For this reason, you do not need to worry about applying epoxy before the temperature drops at night. However, if you do need to increase the curing rate, you can use a source of heat to speed this up.