My first colour coat looks patchy. Should I go over it until it is opaque?

No. A first coat you can still see the nail through is exactly thin enough. Cure it and the second coat fills in. Some pale shades and whites need three coats, and that is still better than one thick coat that never cures underneath.

Gel keeps running into my cuticle. What do I do?

Halve the gel on the brush. Place it 1-2 mm from the cuticle and push it up until 0.5-1 mm from the skin. While waiting, tilt the finger so the cuticle sits higher than the tip. If the gel is very runny, apply and cure one nail at a time, and always run a small cleanser-dipped brush along the edge before curing.

My top coat shows brush marks.

Usually pressure or not enough waiting. Top coat can go on a little thicker than colour. Place it in the middle, float the brush outwards without going back over it, and wait until the surface is flat before curing. If marks persist, the gel may be cold or thick; leave the bottle at room temperature for a while before use.

Apply gel smooth and even: thin coats, capping the edge, no flooding

The difference you can see between a home gel manicure and a salon one is usually smoothness. The salon finish looks like glass; the home one has waves, a groove down the middle, or a thick ridge on one side. None of that is about expensive or cheap gel. It is about how much is on the brush, which way the brush moves, and whether the gel gets a moment to do its own work. This lesson takes those techniques one at a time. It assumes the nail is already prepped as in nail prep without damage.

Why gel goes wavy

Gel is a viscous liquid that keeps flowing slowly until lamp light hits it. That is a feature: given the chance, it flows into a flat surface on its own, which is called self-levelling. It is also a problem, because it flows to the lowest point as well.

Waves come from three things:

Thick coats. More gel means more flow, pooling at the side walls or cuticle, and a surface that starts to set before the layer underneath, which wrinkles.
Brush pressure. Bristles pressed down to the nail push the gel aside into a groove: too little gel on the groove, too much beside it.
Curing too soon. Fresh gel still carries brush marks. Put it straight in the lamp and those marks get locked in.

Thin coat, floated brush, wait for it to level, then cure. The same order for base, colour and top.

Two thin coats beat one thick one, every time

Load the brush lightly

Lift the brush out of the bottle and scrape one side clean on the neck, leaving gel on one face only. For a colour coat, the bead on the tip should be smaller than feels right: enough for one nail, with the brush nearly dry when you finish. If the brush still feels heavy after a nail, it was overloaded from the start.

A good sign: after the first coat you can still faintly see the nail through the colour. That is the right thickness. The second coat fills it in.

Three strokes

Place and push. Set the bead in the centre of the nail about 2 mm from the cuticle, then nudge the brush slowly towards the cuticle. Stop 0.5–1 mm from the skin. The curved edge of the gel should follow the shape of the cuticle.
Pull down the middle. From there, pull the brush straight down to the tip in one stroke, letting the bristles float on the gel rather than touch the nail. The only pressure is the weight of the brush.
Pull both sides. One stroke left and one right, parallel to the centre line, leaving the same 0.5–1 mm at the side walls. If a patch is missed, fill it after this cure, not by going back over wet gel.

On a wide nail, place a slightly bigger bead in the centre and spread it, rather than reloading the brush several times.

Cap the free edge

The tip meets everything in daily life first. If the gel stops at the top edge, that edge is where peeling starts. After the three strokes, turn the brush on its side and sweep the nearly dry bristles once along the cut edge of the tip, from one side to the other, so a thin film covers the edge without running underneath.

Do it on every layer: base, colour and top. Application guides from large gel makers list this step on every coat. If gel does run under the nail, wipe it off with a small brush before curing or it cures into a lump that catches on everything.

Keep gel off the skin (flooding)

Gel on skin costs you twice. The coat lifts from that spot because it is attached to skin, not nail, and skin that meets uncured gel repeatedly is the main route to an allergy. So:

Leave 0.5–1 mm from the skin on every side. An even gap looks tidier than a coat that runs right up to, and over, the cuticle.
While the gel levels, hold the finger with the cuticle higher than the tip. Gel flows towards the tip, not into the skin.
With a runny formula or a warm room, apply and cure one nail at a time instead of finding that nail one has flooded by the time nail five is done.
Before every trip to the lamp, look at the cuticle and side walls under the light. If gel has crept over, run a small brush dipped in cleanser along the edge to pull it back, then wipe the brush on a lint-free pad.

Let it self-level

Count 5–10 seconds after painting before curing. Tilt the finger so light reflects off the gel. A broken reflection line means brush marks are still there: wait a little longer. A continuous, smooth reflection means it is ready. Formulas level at different speeds, and most top coats flow faster than colours. If gel runs so fast that it pools at the edges, the coat is too thick, not the wait too long.

Some makers’ troubleshooting guides say so plainly: gel that shrinks back towards the centre of the nail is down to not giving it time to self-level before curing, and to overloading the brush.

Thin coats also fix heat and under-curing

Gel hardens through a reaction that gives off heat. The thicker the layer, the more gel reacts at once, and the more heat reaches the nail bed underneath. That is the stinging flash in the lamp, which thumbs get most often because they are painted thickest. A thick layer also stops light reaching the bottom, so the gel underneath stays soft, and lifting and wrinkling follow. Heat and cure times get their own lesson in curing temperature and time.

If a nail feels hot in the lamp, slide the hand out for a moment and go back in. Next time, paint thinner, and use a low-heat mode if the lamp has one.

Worked example: two thin coats versus one thick one

Say the colour’s label gives 30 seconds per coat in an LED lamp (check your own gel’s label for the real number), and the same total amount of colour is needed for full opacity.

	Two thin coats	One thick coat
Gel per nail	small bead × 2	large bead × 1
Cure time per hand	30 + 30 = 60 s	30 s (but the bottom often stays soft)
Levelling wait	10 + 10 = 20 s	10 s
Total per hand, excluding painting	about 1 min 20 s	about 40 s
Surface after cure	flat, crisp edges	pooled at the edges, likely to wrinkle
Heat in the lamp	low	higher, often stings
Chance of lifting in week one	low	high, from the uncured bottom

Across both hands, two thin coats cost about a minute and a half more than one thick one, and remove the three most common problems in one go.

Symptoms and fixes

Symptom	Usual cause	Fix
Wavy or wrinkled surface	Thick coat, or bottom layer not cured	Halve the thickness; add a coat instead
Groove down the middle, brush lines	Bristles pressed to the nail, repeated strokes	Float the brush, one stroke per line, wait to level
Gel shrinks away from cuticle and sides	No levelling time, overloaded brush, or unclean prep	Wait 5–10 s before curing, load less, buff and cleanse again
Thick ridge on one side	Finger tilted while waiting, or started from an edge	Start in the centre; hold the finger level
Gel in the cuticle	Too much on the brush, bead placed at the cuticle	Place 2 mm away and push up; wipe before curing
Peeling from the tip	No capping, or gel under the nail	Cap every layer with a nearly dry brush
Patchy colour	First coat forced opaque, brush running dry	Accept a thin first coat; fill on the second
Stinging in the lamp	Thick coat, especially thumbs	Thinner coats, slide the hand out briefly, low-heat mode

Common mistakes

Loading the brush full to get opacity in one go. The root of almost every row in the table above.
Painting right up to the skin to avoid a visible gap. An even 0.5–1 mm gap looks tidier than gel over the cuticle, and it is safer.
Curing the second the brush lifts. The gel has not levelled; brush marks get locked in.
Fixing a mark in wet gel by going over it. Every pass makes a new groove. Cure, then correct on the next coat.
Top coat as thin as colour. Top can go slightly thicker than colour so it flows flat, but never thick enough to pool at the edges.
Old colour cured on the brush. Hardened gel in the bristles drags lines. Wipe the brush on a lint-free pad every time you change bottles.

Safety

Uncured gel contains acrylate/methacrylate ingredients that can cause an allergy with repeated skin contact. Wipe gel off skin before every cure and do not touch the sticky layer with bare fingers. Work in a ventilated room, cap bottles when not in use, and keep gel away from the lamp’s light. If a nail feels very hot or painful in the lamp, take the hand out at once. If you get a rash, itching or swelling around the nails, or a nail separating from its bed after a manicure, stop and consult a doctor. This is beauty information, not medical advice.

Sources

General guidance. Products differ between brands: always follow the label. If you react to a product, see a doctor.