Builder gel is one of the most talked about products in the nail industry, but it’s also one of the most misunderstood. Products like Builder in a Bottle (also known as BIAB™) are more than usually soft, soak-off builder gels designed to strengthen natural nails, add structure, and allow for small extensions or repairs (this depends on brand and formulation).
While BIAB™, shot to fame in 2015 when The Gel Bottle introduced their bottled format, brands such as Bio Sculpture and Calgel had already been offering similar soakable gels long before, applied from a pot with a brush . The bottled version simply made builder gel more accessible worldwide. With that steep rise in popularity, poor education and home use, came a surge in misuse, leading to nail damage, lifting, and even allergies.
👉 Note: This blog focuses on softer, soakable builder gels in a bottle (BIAB™ style products). If you’d like clarification on the difference between hard gel vs soft builder gel, please see my dedicated blog here .
The good news? With correct builder gel application, you can avoid these problems completely, keeping natural nails healthy, strong, and safe.
Why Correct Builder Gel Application Matters
Whether you’re a qualified nail technician or just starting out as a home user, it’s your responsibility to make sure any nail covering is applied safely. Correct application ensures:
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Proper adhesion – builder gel stays put, preventing lifting and chipping.
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Full cure – minimises the risk of uncured product, which can cause allergies in the long term. It also leads to lifting, adhesion issues and further complications such as pseudomonas.
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Healthy results – the natural nail remains strong, without thinning or damage.
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Professional finish – smooth, structured nails ready for gel polish.
Many of the builder gel mistakes I see online, stem from poor prep, using an insufficient lamp, or applying the product far too thickly. Getting these basics right makes all the difference.
Step 1: Nail Prep
Proper nail preparation is the foundation of every set of BIAB nails.
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Perform cuticle work carefully and remove all non living tissue.
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Ensure the cuticle pocket is fully open and clean, if this area isn’t clear, the product will lift quickly.
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Avoid over-filing. This thins the nail and increases the risk of allergies.
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Ensure the nail is completely free from dust, oils, and debris.
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Finish prep with isopropyl alcohol/acetone for a squeaky-clean base.
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Don’t forget to clean the sidewalls and cuticle pocket using an orangewood stick wrapped in a lint-free wipe and prep liquid of choice.
Remember: Clean cuticles = perfect adhesion and no lifting.
Step 2: Base Layer
A base coat is essential, no matter which brand you’re using. Always use the base gel from the same brand as your builder gel. You may need a standard base or a rubber base. This will depend on your clients natural nails.
Why?
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It provides a flexible foundation.
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It bonds tightly to the natural nail.
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It acts like a shock absorber, preventing cracking and lifting.
Skipping a base layer is one of the most common builder gel mistakes, and one of the easiest to fix. There are the odd client that fairs better without a basecoat, this will be part of your prescriptive services.
Step 3: Applying Builder Gel
The correct amount of builder gel depends on nail length and structure. Here’s a quick guide:
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Super short nails: thin base coat, thin slip layer, and a small bead for the tiniest apex. We do not want a dumpling shaped nail.
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Short nails (just past smile line): thin base coat, thin builder layer/cure, slip layer, and a small structure bead.
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Medium to long nails: thin base coat, 1/2 thin builder layers/cure, thin slip layer, and a small structure bead.
⚠️ Never drag a big blob of builder gel down the nail all in one go. This “one bead swoosh” trend looks quick but leads to undercuring, product breakdown, and a higher risk of allergies, especially with opaque gels.
Instead:
✅ Work in thin, controlled layers.
✅ Cure fully after each step.
✅ Keep the cuticle area seamless with no visible ridge.
This method ensures strong, smooth nails every time.
Step 4: Finishing the Nail
This stage is often skipped, but it makes the difference between average nails and a flawless finish.
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Refine with a 180/240 grit file to smooth the surface. My preferred grit is 220/240.
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Correct any lumps or bumps, uneven structure can cause lifting.
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Avoid heavy filing at the cuticle, the product should already be thin here. Unnecessary pressure over this area can disturb adhesion.
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Lightly buff the surface and remove all dust before gel polish application.
👉 If your technique isn’t good enough to move on without refining, don’t move on. A messy, unstable finish can lead to lifting, poor gel polish application, and unhappy clients who may not return.
✨ A smooth finish = professional looking nails.
Common Builder Gel Mistakes to Avoid
Even experienced nail techs can slip into bad habits. Here are the top mistakes I see:
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Applying too thickly: leads to undercuring, leaving uncured product on the nail (a major cause of allergies).
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Flooding sidewalls: always pull back the skin and use a liner brush to guide your product into place if needed.
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Skipping prep: rushing this stage ruins adhesion, don’t be tempted.
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Wrong lamp or cure time: always use a recommended suitable lamp, check cure times, and replace lamp regularly .
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Ignoring safety data sheets (SDS): these documents explain how products should be used safely, they’re covered in all my beginner nail courses.
Builder Gel vs Hard Gel
As a quick reminder, builder gels in a bottle are softer, soakable gels, perfect for strengthening natural nails or creating short extensions. Hard gels, by contrast, are non-soakable and require filing off.
This blog covers BIAB/soakable builder gels only. If you’d like a full comparison, see my Hard Gel vs Builder Gel blog .
Final Thoughts
Correct builder gel application is essential for safe, long-lasting nails. Many of the problems we see in the industry lifting, breakage, nail damage, and even allergies, come down to poor application and lack of training.
If you’re serious about nails, avoid cheap shortcuts or generic manuals bought online. Instead, invest in the correct builder gel training with experienced knowledgeable educators who understand the science and application techniques behind the product. Your career and client safety depend on it.
If you’d like to learn how to apply builder gel correctly from start to finish, my online Builder Gel Course covers everything, from nail prep and structure to all theory and common troubleshooting. With personal tutor support and personalised feedback, you’ll gain the confidence to create safe, professional results.
Enrol today for immediate access.
Much Love
Mel xx