How Do You Adhere Ceramic To Ceramic?

Ceramics are inorganic, non-metallic materials that are usually hard, brittle, and resistant to heat or corrosion. Ceramics are made from natural clay, shale, sand or a combination of these materials. Adhesion is the tendency of different materials to cling or stick to one another. Adhering ceramics involves bonding ceramic materials together using an adhesive. This article will cover common uses for adhered ceramics, how to properly prepare the ceramic surfaces, types of adhesives that can be used, application techniques, curing and drying times, and maintenance of the bond.

Common Uses for Adhered Ceramics

Some of the most common uses for adhering ceramics together include:

Tile floors and walls – Ceramic tiles are often adhered to each other and the substrate using adhesives to create stunning and durable floors and walls. The grout between the tiles is also a form of adhesive.

Sculpture and art pieces – Many ceramic sculptures and artworks involve combining individually thrown or molded ceramic components using adhesive. This allows more intricate and complex shapes to be achieved.

Appliances and cookware – Ceramic components are bonded to metal bases in many appliances and cookware items. This allows the durability and heat resistance properties of ceramics to be combined with the strength and thermal conduction of metals.(Source)

Surface Preparation

Proper surface preparation is crucial for achieving a strong, long-lasting bond between ceramic materials. The goal is to thoroughly clean the bonding surfaces and increase their surface area to improve mechanical retention.

Cleaning should be done first to remove any debris, oil, or contaminants. Surfaces can be cleaned with isopropyl alcohol, acetone, or other solvents. Air abrasion or steam cleaning may also be used.

After cleaning, the surface must be roughened to improve adhesion. This is typically done by grinding, sandblasting, or etching with hydrofluoric acid. Mechanical roughening creates micro-retentive features and undercuts that the adhesive can grip onto. Etching with hydrofluoric acid removes glassy phases and selectively dissolves certain crystals to also increase surface area.

The use of primers can further enhance bonding. Primers contain functional monomers like MDP that chemically interact with the ceramic surface. This creates a reactive layer that improves wetting and chemical bonding to the adhesive resin.

Proper surface preparation removes contaminants, increases surface area, and facilitates micro-mechanical retention and chemical bonding between the ceramic and adhesive resin. This multimodal approach leads to the strongest, most durable adhesion.

Adhesive Options

There are several types of adhesives that can be used to bond ceramic to ceramic, each with their own advantages and disadvantages:

Epoxy:

Epoxy adhesives like Loctite Super Glue Liquid Precision provide extremely strong and durable bonds between ceramics. Epoxies cure transparent and can fill small gaps between ceramics. However, epoxy takes longer to cure than some other adhesives.

Silicone:

Silicone adhesives are flexible and waterproof, making them a good choice for bonding ceramics that may shift or expand. However, silicone does not bond as strongly as epoxy and may not be suitable for load-bearing applications.

Acrylics:

Acrylic adhesives like E6000 bond well with ceramics and cure quickly. However, acrylics are not as strong or water resistant as other options. Acrylics work best for indoor, non-load-bearing ceramic repairs.

Mortar:

Mortar adhesives containing cement or epoxy provide the strongest bonds for structural ceramic applications. However, these adhesives are permanent and difficult to remove once cured.

Applying the Adhesive

The key to a strong ceramic bond is proper adhesive application. Be sure to apply the adhesive evenly across the entire surface using a notched trowel. The notches will help spread the adhesive and ensure proper thickness. Generally, a 1/4” x 1/4” square-notched trowel is recommended for most ceramic tiles.

Follow the adhesive manufacturer’s instructions for the amount to apply per square foot. Applying too little adhesive can lead to a poor bond, while using too much can create a mess and lead to excess squeeze-out between tiles.

It’s also important to carefully follow the adhesive’s specified open time or pot life. This is the window where the adhesive is still usable after being applied. Open time can vary widely between adhesive types, anywhere from 10 minutes to over an hour. Going past the open time will result in a weak bond. Keep a close eye on the clock once the adhesive is applied.

Bonding the Ceramic

When applying adhesive to bond two ceramic pieces, it is important to apply even pressure across the bonding area. This ensures maximum surface contact and a strong bond. Using clamps or weights to apply steady pressure is recommended. According to Loctite, their super glue liquid requires clamping pressure for 30-60 seconds. Allowing the adhesive to cure under pressure prevents movement or shifting of the ceramic pieces while the glue sets.

The clamping time will vary based on the adhesive used. Quick-setting epoxies may only require clamping for 5-10 minutes, while slower-curing adhesives need extended clamping time of up to 24 hours. It’s important to follow the manufacturer’s instructions for clamping or curing time to achieve maximum strength. Releasing clamps or weights before the adhesive has fully cured can compromise the bond.

Grout and Sealants

After the ceramic tiles have been adhered, it’s important to use grout between the tiles to fill in any gaps and create a uniform surface. Standard sanded grout is commonly used for joints wider than 1/8 inch, while unsanded grout is used for narrower joints. Make sure to follow the grout manufacturer’s instructions on mixing and applying the grout. Using a grout float or squeegee, work the grout into the joints with a diagonal motion pressing firmly to fully pack the joints. Let the grout sit for about 15 minutes before wiping the excess grout off the tile surface with a damp sponge. Allow the grout to cure fully before applying any sealants.

Sealing the grouted ceramic tiles and joints is highly recommended as a final step. Sealants create a protective barrier that prevents stains from seeping into the porous grout. Solvent-based silicone sealants work well for sealing ceramic tile [1]. Apply the sealant to the grouted areas with a paintbrush or sponge, let it penetrate for 5-10 minutes, then wipe off any excess. Allow the sealant to cure fully before using the newly tiled surface. Reapply the sealant every 1-2 years for ongoing protection.

Curing and Drying Time

After applying the adhesive, it’s important to follow the recommended cure times before subjecting the ceramic pieces to any stresses. This allows the adhesive to fully harden and create a strong, rigid bond between the ceramics. According to Cotronics, a manufacturer of specialty adhesives, typical room temperature cure times range from 4-16 hours followed by a post-cure at 250°F for 2 hours. ¹

During the curing period, it’s advisable to clamp the ceramic pieces together to ensure maximum surface contact while the adhesive sets. Applying even clamping pressure allows the adhesive to form the strongest bond across the entire joint. Be sure to use non-marring clamp pads to avoid damaging the ceramic surfaces.

Allowing the full recommended cure times is crucial before subjecting the adhered ceramics to any stresses or high temperatures. Insufficient curing can cause joint failure. Check the technical specifications of the selected adhesive for exact cure schedules and post-cure requirements.

Maintenance

Proper maintenance is essential for keeping adhered ceramics looking their best. Be very gentle when cleaning to avoid disrupting the adhesive bond. Use a soft cloth or sponge dampened with warm water to wipe away dust and dirt. Avoid abrasive cleaners or scrubbing that could scratch the surface. According to the Canadian Conservation Institute, neutral pH cleaners are safest for cleaning ceramics.

Reapply sealant periodically per the manufacturer’s recommendations to protect the grout lines and help prevent stains. Take care not to get sealant on the ceramic tile surface itself, as this could create a cloudy appearance. Allow proper drying time after resealing before using the adhered ceramics. With routine gentle cleaning and proper resealing, adhered ceramics can maintain their beauty for many years.

Conclusion

In summary, adhering ceramic to ceramic requires careful surface preparation, choosing the right adhesive, and following proper application techniques. The most common adhesives used are epoxy, cyanoacrylate “super glue”, and acrylic-based adhesives. Epoxy provides the strongest, most durable bond but takes longer to cure. Cyanoacrylate glue offers quick adhesion and dries transparent, but has lower heat resistance. Acrylic adhesives offer moderately strong adhesion with more flexibility after curing.

When bonding ceramic, it’s critical to roughen the surfaces first via sanding or etching for the adhesive to mechanically interlock. Apply the adhesive evenly in a thin layer, press the ceramics together firmly, and allow adequate time for curing based on the product directions. With proper adhesion procedures, the joint should be durable and withstand daily use and cleaning.

For most small-scale ceramic adhesion projects, cyanoacrylate glue or two-part epoxy provide reliable bonding. For high-heat applications, epoxy is the best choice. Always check the manufacturer’s instructions for the optimal adhesive selection and application method. With careful surface prep and adhesive application, even novice DIY-ers can securely adhere ceramics for beautiful finished projects.