Quick Answer: A BIAB infill is a maintenance appointment every 3 to 4 weeks where your nail tech files back the existing builder gel, preps the new growth with a dry Russian manicure, then rebuilds the structure and apex over the whole nail. Nothing is fully removed unless it needs to be, which is why infills are the gentlest way to keep BIAB gel nails strong and healthy.
TL;DR
- An infill rebalances your BIAB as your natural nail grows out, usually every 3 to 4 weeks.
- Most of the old product stays on as a base. Only what is needed gets filed back.
- The new growth is prepped with a dry Russian manicure before fresh BIAB goes on.
- The apex is rebuilt in the right place, which is what stops nails snapping.
- Infills protect your natural nail far better than soaking off with harsh acetone every appointment.
*“Is an infill just a top-up at the cuticle?” No, it’s not, it’s basically a full, dry removal, and then reapplication, therefore taking longer than the initial appointment on bare nails. A proper BIAB infill is a full rebalance, and knowing what happens in the chair makes it easy to tell a good one from a rushed one.*
If you wear BIAB, the infill is the appointment you will book most often. As a Melbourne nail tech working 1:1 at Apricot Nails in Hawthorn, I do more infills than any other service, so here is exactly what happens, step by step.
Why BIAB Needs an Infill at All
Your nail grows roughly 3mm a month, and the BIAB moves forward with it. A gap opens at the cuticle and the apex (the strongest point of the structure) slides towards the tip. By week 3 or 4 the nail is carrying weight in the wrong place, and that is when lifting and breaks start. An infill resets all of that.
The BIAB Infill, Step by Step
Step 1: Assessment
I check every nail for lifting, cracks and how the structure has grown out. This decides whether you get a straightforward infill or whether a nail needs repair work first.
Step 2: File back, not off
Using an e-file, I reduce the existing BIAB to a thin, even base. Any lifted or compromised product is removed completely. The well-bonded product stays, because it is protecting your natural nail.
Step 3: Russian manicure prep on the new growth
The freshly grown nail near the cuticle is prepped dry with a [Russian manicure](https://ashwhite.co/nail-diaries/russian-manicure-hawthorn-melbourne-what-it-is). Dead tissue is lifted from the nail fold so the new BIAB can bond right at the base without touching skin.
Step 4: Rebuild the structure
Fresh BIAB goes over the whole nail, not only the gap. This is where the apex is rebuilt in the correct position for your current length, so the nail is balanced again from cuticle to tip.
Step 5: Shape, colour and finish. Once cured, I refine the shape, add your colour or leave it sheer, and finish with top coat and cuticle oil.
Nail tech tip: if an “infill” only adds gel at the cuticle and leaves the old apex sitting near your tip, the nail is still unbalanced. Ask your tech if they rebuild the structure every time.
How Long Does a BIAB Infill Take?
Allow around 90 minutes at Apricot Nails. Because the studio is 1:1, the time goes into prep and structure rather than rushing to fit the next client in. You can see how appointments run on the What to Expect page.
Infill or New Set?
There is a longer breakdown in BIAB infill vs new set, and if you want to know when to book, read how often you should get BIAB infills.
Frequently Asked Questions
What is a BIAB infill?
A BIAB infill is a maintenance appointment where the existing builder gel is filed back to a thin base, the new growth is prepped, and fresh BIAB is applied to rebuild the structure. It keeps nails balanced without removing all the product.
How often do you need a BIAB infill?
Most people need a BIAB infill every 3 to 4 weeks. Short, gentle wearers can sometimes stretch a little longer, but waiting past lifting or chipping risks damage to the natural nail.
Is a BIAB infill better than soaking off?
Yes, for most people. Infills avoid repeated acetone soaks and full removals, which is kinder to the natural nail and supports healthy nails long term.
How long does a BIAB infill take?
Around 90 minutes at Apricot Nails in Hawthorn, including assessment, Russian manicure prep, rebuilding the structure and finishing.
Can I get a BIAB infill if my last set was done elsewhere?
Often yes, if the product is well bonded. If there is heavy lifting or an unknown product, a removal and new set is the safer start.
Due for a rebalance?
Book your BIAB infill in Hawthorn, or check the BIAB FAQs if you still have questions.
Book Your BIAB Infill
Private 1:1 studio · 37 Lynch Street, Hawthorn · Structure rebuilt every time