Nail primer is an adhesion product that helps the natural nail bond reliably with a layer of gel, acrylic or gel polish. Before that, a dehydrator removes oils and moisture from the nail surface, and a cleanser is used at the end to wipe off the sticky layer. All three products look similar, but they do different jobs and are used at different stages of the service.
Why gel lifts: the chemistry of adhesion in plain terms
The nail plate is made of keratin, and its surface always carries natural oils and moisture. Gel polish, gel and acrylic are (meth)acrylate-based materials that bond poorly to an oily, damp surface. Reliable adhesion comes down to three things:
- Mechanical adhesion. Removing the shine with a file creates a microscopic roughness that the product can "grip".
- A clean surface. No oils, moisture, dust or dead cuticle should be left on the nail.
- A chemical bond. This is the primer's job: it acts as the go-between for the nail and the coating.
If even one of these is skipped, the coating starts to lift from the edge or around the cuticles. We cover other causes of lifting and splitting in the article "Why gel polish cracks".
Dehydrator (nail prep): when and how
A dehydrator (also called nail prep) temporarily removes oils and moisture from the nail surface. It is not cured in the lamp and evaporates within moments.
- First tidy the cuticles, remove the shine with a file and brush off the dust.
- Apply the dehydrator to the whole nail surface, including the free edge.
- From this point on, do not touch the nails with your fingers and avoid long pauses – the nail naturally regains moisture and oils.
For example, the "Prep" nail degreaser suits all systems: gel polish, gel, acrylic and polygel.
Acid and non-acid nail primer – what's the difference
Acid primer is classically made with a methacrylic acid base. It works as a two-sided link: one part of the molecule bonds to the keratin of the nail, while the other polymerises in the lamp together with the gel or acrylic. This gives the strongest adhesion, but the acid irritates the skin and can burn it, so it is applied very sparingly and only on the nail. For example, the "Primer" acid adhesion promoter, 9 ml needs no curing and dries on its own.
Non-acid primer works not through acid but through other adhesion-improving ingredients. It is gentler on the nail and cuticles, so it is most often used for gel polish. For example, the "Ultra bond" adhesion promoter is non-acid, free of methacrylic acids and, according to the manufacturer, does not irritate the nail or cuticles.
| Acid primer | Non-acid primer (bonder) | |
|---|---|---|
| How it works | Acid bond between keratin and coating | Adhesion-boosting layer without acid |
| When to choose it | Acrylic, extensions, oily and "non-holding" nails | Gel polish, thin and sensitive nails |
| Effect on skin | Irritates, can burn | Gentler, but still keep it off the skin |
Bonder (adhesion promoter) and when it is enough
"Bonder" usually refers to a non-acid adhesion layer, but different manufacturers use the names inconsistently. So look not at the name but at the description: is the product acid-based or acid-free?
- A bonder is enough when the nails are healthy and not very oily, and gel polish is applied over a rubber or strengthening base.
- An acid primer is worth choosing when the coating keeps lifting despite good prep, when nails are oily or damp, and when working with acrylic and building longer nails.
The instructions for our "Primer" and "Ultra bond" recommend lightly priming the nail tips, applying sparingly, avoiding contact with the skin and letting the product dry for about 30 seconds.
Tacky-layer cleanser: when it is needed and when it is not
After curing, many bases, gels and top coats leave a sticky layer. This is uncured material: oxygen in the air prevents the surface from polymerising completely.
- Do not wipe between layers. A tacky base or colour surface helps the next layer adhere.
- Wipe at the end when you use a tacky top coat. A no-wipe top coat does not need a cleanser.
- Wipe before filing gel, so the file does not clog or get smeared with uncured material.
- Protect the skin. The tacky layer is uncured product, so do not touch it with your fingers and throw the used wipe away straight away. Repeated contact with uncured gel is one of the most common causes of gel polish allergy.
A handy all-round choice is the "4in1" cleanser: it removes the tacky layer, is suitable for cleaning brushes and degreases the nail plate.
The prep routine: where each product goes
So the products don't get mixed up, here is the typical routine before gel polish or extensions:
- Tidy the cuticles and remove the shine with a file.
- Brush off the dust.
- Dehydrator on the whole nail.
- Primer or bonder in a thin layer, wait until it dries.
- Base or gel, cure in the lamp (do not wipe the tacky layer).
- Colour or sculpting layers.
- Top coat and, if it is tacky, cleanser at the end.
Most common mistakes: too much primer, damaging the cuticles
- Too much primer. More is not better: the excess runs into the cuticles, irritates the skin and does not improve adhesion. A thin layer is enough.
- Primer on the skin. Acid primer can cause burning and redness. Wipe the excess off the brush on the neck of the bottle and keep away from the cuticles.
- Primer instead of a dehydrator. Primer is no substitute for degreasing – it goes on a nail that has already been prepped and degreased.
- Wiping the tacky layer between layers. This makes the layers bond less well and the coating starts to delaminate.
- Leaving the bottle open. These products are volatile, evaporate quickly and lose their properties, so close the bottle straight away.
Which products to choose for gel polish, gel and polygel
- Gel polish: dehydrator, non-acid primer or bonder (for problem nails – acid on the tips), base coat. A cleanser is needed if the top coat is tacky. You will find the full routine in the article "How to apply gel polish correctly".
- Gel (extensions, strengthening): dehydrator, primer (often acid), a thin layer of base or gel. Cleanser – before filing and at the end.
- Polygel: dehydrator and primer or bonder. Polygel slip solution is only for wetting the brush and is no substitute for primer.
- Acrylic: dehydrator and usually an acid primer.
Frequently asked questions
What is nail primer?
It is an adhesion product applied to a prepped, degreased nail before the base, gel or acrylic. It creates a bond between the natural nail and the coating, so the coating lifts less.
Do you need primer for gel polish?
For healthy nails with a good base, a non-acid primer or bonder is often enough. If the coating keeps lifting, it is worth trying an acid primer on the free edge, but first check that your nail prep is thorough.
What is the difference between acid and non-acid primer?
Acid primer works through an acid bond with the keratin and gives the strongest adhesion, but it irritates the skin. Non-acid is gentler and better suited to gel polish and sensitive nails.
What is a tacky-layer cleanser for?
To wipe off the sticky uncured layer after the top coat and before filing gel. There is no need to remove tackiness between the base and colour layers.