Introduction: why is your choice of adhesive important?
There are several types of mosaic glue — PVA, silicone adhesive, tile mortar, and epoxy — each with its own field of application. This guide focuses on silicone adhesive: what it is, when it makes sense to use it, how to apply it correctly, and when you are better off choosing an alternative.
What is Olba Products?
Olba Products is a Dutch brand that has been developing high-quality adhesives for hobby and professional use for over 35 years. Their range includes industrial glues, sealants, and silicone adhesives, and is regularly used by hobbyists and DIYers working with a variety of materials.
In the mosaic sector, Olba Products silicone adhesives are widely used, particularly because they dry transparent and are suitable for both indoor and outdoor applications. In addition to adhesives, Olba Products also offers accessories such as dosing syringes and precision hobby knives that are useful for accurate detail work.
Which Olba Products silicone adhesives are available?
Olba Products offers two sizes of silicone adhesive suitable for mosaic work:
An 80ml tube, practical for smaller projects and precision work. The screw-off cap ensures a good shelf life after opening.
- Small-scale projects
- Glass-on-glass applications
- Precision work with a dosing syringe
- Detail work
A 200ml pressurized cartridge that works on gas pressure — no separate caulking gun required. Suitable for larger projects or frequent use. Stays usable for a long time after opening.
- Larger projects
- No caulking gun required
- 3D mosaic and outdoor work
- Long shelf life after opening
Shared Properties
Both variants are suitable for use on ceramics, glass, stone, wood, metal, and styrofoam (isomo).
What is silicone adhesive?
Silicone adhesive is a flexible, rubber-like adhesive based on silicone — the same substance used in caulks and sealants. In the mosaic world, a specific variant is used: a transparent, thick paste that cures slowly and remains flexible after drying.
Key Features
- Dries completely clear — no visible glue residue with glass or translucent tiles
- Thick, slow consistency — tiles do not slide out of place during positioning
- Flexible after drying — withstands minor movements and temperature variations
- Moisture resistant — holds up well against rain and changing weather conditions
- Slow curing time — provides more working time, but requires patience before grouting
The biggest difference compared to regular PVA glue is its water resistance and completely transparent drying. The main disadvantage is that silicone adhesive cures more slowly and is harder to remove once applied.
When to use silicone adhesive?
Silicone adhesive is not the most obvious choice for every mosaic project. It truly shines in a few specific situations:
Glass-on-Glass
When creating glass mosaics on a glass backing, transparent drying is essential. Ordinary PVA glue leaves a white haze that becomes visible through the glass. Silicone adhesive dries crystal clear, keeping the final result visually flawless.
3D Mosaic and Irregular Shapes
On spheres, flower pots, sculptures, or other three-dimensional shapes, you need an adhesive that keeps the tiles firmly in place. The slow, thick consistency of silicone adhesive is highly suitable for this.
Outdoor Mosaics
Artworks placed outdoors have to deal with rain, frost, and temperature changes. Silicone adhesive is waterproof and maintains its bond under varying conditions. PVA glue is not suitable for this purpose.
Vertical Surfaces
When doing mosaics on walls or vertical panels, there is a high risk of tiles sliding down before the adhesive cures. The thick consistency helps prevent this without requiring you to secure the tiles with tape.
When is silicone adhesive less suitable?
It is helpful to understand its limitations as well:
- Large, flat surfaces — for expansive tiled floors or walls, cement-based tile mortar is more efficient and economical
- Time-sensitive work — the drying time is 12 to 24 hours; those wanting to progress quickly often opt for fast-drying PVA
- Porous or rough surfaces — on coarse concrete or stone, tile mortar distributes much better
- Plastics such as Teflon, polyethylene, and polypropylene — silicone adhesive does not adhere well to these
- Tiles with a foil backing (e.g., mirrors) — always use a pH-neutral adhesive for these
- Simple 2D indoor projects — PVA glue is easier to use and much easier to clean up
Comparison: which glue for which project?
The table below provides an overview of the most commonly used adhesive types in mosaic art:
| Adhesive Type | Dries Transparent? | Suitable Outdoors? | Ideal For | Disadvantages |
|---|---|---|---|---|
| PVA Glue | Yes (slightly hazy) | No | 2D, indoor, beginners | Not water-resistant |
| Silicone Adhesive | Yes, completely clear | Yes | Glass-on-glass, 3D, outdoor, vertical | Slower curing, harder to clean |
| Tile Mortar / Thinset | No (white/grey) | Yes | Large surfaces, rough backings | Thick, less suitable for fine detail |
| Epoxy | Depends on type | Yes | Strong bond, non-porous materials | Expensive, two-component, short working time |
No single adhesive is the best choice for every situation. Always choose based on your specific project: the material, location, size, and your own level of experience.
How to use silicone adhesive step by step?
Below you will find a practical guide, specifically tailored for the Olba Products Silicone Adhesive Automatic 200ml. The steps for the 80ml tube are largely identical, minus the actions specific to the cartridge.
- Prepare the surfaceEnsure the surface is clean, dry, and free of grease. Remove any dust, rust, or old adhesive residue. A contaminated surface is the primary cause of poor adhesion.
- Break the seal
Unscrew the white nozzle and remove the cap to break the factory seal. - Activate the cartridge
Press the black lever down. The cartridge runs on gas pressure — no caulking gun is needed. The adhesive is now ready to use. - Apply the adhesiveApply a thin, even layer to the back of the tile or directly onto the surface. Use a dosing syringe for precise detail work. Applying too much glue does not create a stronger bond — it just squeezes out and is difficult to remove.
- Place and press downPress the tile down firmly but carefully. You have plenty of time to reposition it thanks to the slow drying time. On vertical surfaces, the thick consistency will hold the tile in place.
- Close the cartridge properly
After use, turn the white nozzle back a quarter turn to prevent adhesive from leaking. Close the tube with the red cap and ensure it is secured tightly. - Allow to cure completelyWait at least 12 to 24 hours before you begin grouting. The adhesive must be fully cured; otherwise, the grout can trap moisture and weaken the bond.
- Remove adhesive residueAllow any excess glue to cure fully first. Scrape the residue away with a utility knife or use a glue eraser. Do not attempt to wipe away wet silicone adhesive — doing so will only smear it.
Common Mistakes Made by Beginners
- Applying too much glue — a thick layer does not offer a stronger bond, but it does cause excess residue to squeeze out and lengthens drying time.
- Grouting too early — if the adhesive is not fully cured, tiles can shift and the grout will not dry properly.
- Greasy or dusty surfaces — even a tiny layer of grease or dust will break the adhesion. Always clean the surface first.
- Wrong glue for the material — always use a pH-neutral adhesive for tiles that have a foil backing.
- Using silicone adhesive for large, flat projects — for a 1m² mosaic panel, tile mortar is faster, cheaper, and easier to work with.
Conclusion
Silicone adhesive is an excellent choice when working with glass-on-glass, 3D shapes, outdoor projects, or vertical surfaces. Its transparent drying and water resistance are its main advantages. Olba Products offers two practical sizes for this purpose: an 80ml tube for small-scale and precision work, and a 200ml cartridge for frequent or larger use.
For simple indoor 2D projects, PVA glue is faster and easier. For large surfaces, tile mortar is more efficient. Understand the limitations of your materials, prepare your surface well, and give the adhesive plenty of time to cure.
Frequently Asked Questions
Below you will find answers to the most frequently asked questions about Olba Products silicone adhesives.
- The 200ml Automatic is a choice for ergonomics and efficiency. The gas pressure system eliminates the need for physical force, which is helpful during long projects or for users with hand issues. Additionally, its shelf life after opening is excellent, meaning the price per effectively used milliliter is often lower.
- The adhesive is designed to dry completely crystal clear. This is crucial for glass-on-glass mosaics, where a white or yellow glue line would disrupt the aesthetics of the transparent glass. In very thick layers, slight refraction may occur, but clarity is maintained.
- Yes. The adhesive is waterproof and retains its elasticity between temperatures of approximately −40°C to +150°C. This flexibility ensures that the bond does not snap when materials expand or contract due to temperature fluctuations.
- In the 200ml Automatic cartridge, the adhesive stays good for months due to minimal exposure to air. The 80ml tube features a metallized lining, giving it a shelf life of over 1.5 years, provided the cap is tightly screwed on and the tube is stored in a cool, dry place.
- Yes, its acid-free formulation prevents the reflective silver layer on the back of the mirror from being damaged. This is a significant advantage over standard sanitary sealants, which often cause black spots to appear on mirrors.
- Under normal conditions (23°C, 50% relative humidity), the skin formation time is roughly 7 to 15 minutes. This is the period during which the adhesive remains tacky enough to bond and reposition materials.
- Wet adhesive residue can be gently wiped away with a cloth or removed with a glue eraser. Once the adhesive has cured on hard surfaces like tiles, it is best removed by carefully scraping it off with a sharp utility knife or scraper.
- Yes, the adhesive is odorless and contains no harmful fumes, making it suitable for creative projects with children from around 7 years of age. Adult supervision is still recommended to prevent accidental ingestion or contact with eyes.
- Slip resistance means that the adhesive has a high initial viscosity. Because of this, heavy mosaic tiles or decorations stay right where you place them without sliding down, even on vertical walls or curved surfaces. This eliminates the need to manually support each piece while it dries.
- The adhesive bonds well to many hard plastics such as PVC, plexiglass, Perspex, and Lexan. Adhesion to "greasy" plastics such as polyethylene (PE), polypropylene (PP), and Teflon (PTFE) is limited — this is true for almost all types of adhesive.
- Yes, the silicone-polymer structure is stable against ultraviolet radiation. This means the adhesive will not yellow, become brittle, or lose its bonding strength, even if the object sits constantly in full sunlight.
- With the Automatic 200ml, clogging rarely happens if the cap is used properly. If a small plug of cured adhesive does form in the nozzle, it can be removed with tweezers or a thin piece of wire. The internal pressure of the cartridge helps push the plug out once the blockage is loosened.
- This depends on the thickness of the adhesive layer and the size of the joints. On average, 200ml of adhesive can bond about 0.25 to 0.4 square meters of mosaic at a standard layer thickness. Using dosing syringes makes the consumption significantly more economical.
- No, Olba Products silicone adhesive is solvent-free. This explains why the adhesive is completely odorless and can be safely used on materials that are sensitive to chemical degradation.
- The recommended storage temperature is between 5°C and 25°C. Although the adhesive can withstand extreme temperatures once cured, long-term storage in a very hot environment can affect the chemical stability of the unused adhesive and shorten its shelf life.
