Understanding BIAB Refills

Refills are where the real magic of BIAB happens. This is the stage that allows your client’s natural nails to grow long, strong, and beautifully supported beneath the builder base. Instead of starting from scratch every few weeks, refills maintain the existing structure, reinforce the strength of the nail, and extend the life of your work.

Regular refills don’t just keep the nails looking fresh, they’re key to promoting healthy growth and preventing unnecessary damage or lifting. It’s also your chance to assess the nails’ condition, perfect the apex and balance, and make small adjustments that improve longevity and comfort.

By mastering refills, you’re helping your clients enjoy the best part of BIAB as they watch their own nails grow stronger, healthier, and more beautiful with every appointment!

Universal Hygiene & Safety Protocol Reminder

Before beginning this service, ensure:

  • Hands are sanitised (technician and client)
  • Tools and implements are disinfected
  • Workstation is cleaned and prepared
  • Gloves and mask are worn
  • All health and safety protocols outlined in the Hygiene, Health & Safety section are being followed

Step by Step Overview: BIAB Refills

Below is a quick written guide to support the video demonstration. Use it to stay consistent with every refill and maintain clean, long lasting results.
Click the image alongside to watch the full video tutorial.

1. Remove the Gel Colour with a Carbide Bit:
Using your carbide drill bit, gently file off the gel colour and any nail art until you reach the clear BIAB underneath. You’re only removing the colour layer, not the BIAB structure, so keep a light hand and let the bit do the work. I recommend using around 8000-10000 RPM.

2. Refine the Surface with a Sanding Band (Around (5000 RPM):
Switch to a sanding band and go over each nail to:

  • Remove any lifted BIAB
  • Smooth out the ridge between the old BIAB and the regrowth
  • Even out the surface so your refill blends seamlessly
  • Work slowly and maintain control to avoid thinning the natural nail.

3. Check the Length with your Client:
Before continuing, ask whether they’d like to keep their current length or go shorter. Trim accordingly so the refill is shaped around their preferred length.

4. Shape Each Nail as you go (my personal method):
Shape to your client’s preferred style.
You can:

  • Shape each nail as you go (my preferred method, as it feels less overwhelming)
    OR
  • Shape all nails at the end, both approaches are fine.

5. Cuticle Work and Detailed Cleaning:
Move into your normal prep routine:

  • Trim excess cuticle
  • Use your diamond drill bits to clean around the cuticle and sidewalls
  • Gently refine the regrowth area so the new BIAB sits flush
    Pro Tip: This step is key as a clean base means fewer lifting issues and a smoother final application.

6. Dust and Clean the Nails:
Brush away dust thoroughly using a fluffy brush or wipe. Ensure to do your final tidu up of the nails. At this point the nails should be smooth, shaped, clean, and fully ready for fresh BIAB.

7. BIAB Refill Application:
The application is the same as covered in the BIAB application section but because this is a refill, the structure is already built, so you’ll use far less product.

  • Apply your BIAB bead mainly to the regrowth area
  • Use your fine liner brush to perfect the cuticle and sidewalls
  • Let the BIAB self level and blend into the existing structure
  • Work one nail at a time for maximum control and cleanest blending

8. Cure Each Nail Individually:
Cure each nail immediately after applying to keep the product in place and maintain your structure. It is important to flash cure the thumbs before fully curing to ensure the sides are properly cured.

9. Ready for Gel Polish:
Once all the nails are refilled, smooth, and fully cured, you can move straight into gel colour application as usual.

You’ll see each of these steps demonstrated clearly in the video, which will make the whole refill process even easier to understand and follow.

Pro Tips & Common Mistakes

Refills have their own little challenges, so here are a few quick tips and common mistakes to help keep your results smooth and consistent.

💡 Use a light hand with your carbide bit as you’re only removing colour, not the BIAB structure.

💡 Always check for hidden lifting around the sidewalls and cuticle area before applying fresh product.

💡 Blend the regrowth area smoothly with your sanding band so the new BIAB melts into the old layer without creating bulk.

And just like with any refill, there are a few common mistakes to watch out for to keep your results clean and long lasting.

⚠️ Over filing the natural nail while removing colour, which can cause thinning and sensitivity.

⚠️ Missing small pockets of lifting, which leads to peeling and early lifting after the refill.

⚠️ Applying too much product as the structure is already there, so adding bulk creates thick, uneven nails.

Refills take patience and a steady hand, so don’t rush yourself. Take your time with each step, trust your technique, and remember that every refill you do builds your confidence. Practice truly does make perfect, and you’ll see your speed and precision improve with every set.