Builder gel has become extremely popular both on the web and in salons.
But what is builder gel? How do you know you’re actually getting builder gel? And what are the most common mistakes during application?
Before getting started, If you enjoy today’s topic do consider joining me in my upcoming formal Nail Thoughts Builder Gel application course. Nail Thoughts products are formulated in Japan and are the dedicated bottled gel line for colors and tinted builders of the Japanese gel brand, KOKOIST.
This certification is an online group class event, so you can join from any part of the world where Nail Thoughts by KOKOIST products are offered. You get to take the course with us as a class for support and accountability, and be certified in proper use of Nail Thoughts by KOKOIST products. Enrollment is now open, and you can view all of the details for it HERE.

What is builder gel? How do you know you’re actually getting builder gel?
Here are builder gel’s defining characteristics so that you can easily identify it.
Builder gel is a gel with viscosity to it. This viscosity allows us to structure the nails to give them added support.
Builder gel can be soft or hard gel. A soft builder gel means that the gel is a bit more flexible and can also soak-off in acetone for removal. A hard builder gel is hardly flexible and cannot be soaked off and removed with acetone.
Also the words structure and builder gel are synonymous. These are just descriptive terms used to identify gels with viscosity to them.
A soft builder gel can be found in bottle or pot form, most often a hard builder gel is found in a pot, and in very rare occasions it is offered in a bottle. Always double check with the brands you choose.
In today’s topic, the mistakes we will be addressing will have to do with soft gel bottled builders (sometimes these are referred to as BIAB– which stands for builder in a bottle).
These soft gel bottled builders are often also 3-in-1, base, builder, and color, and are semi-hard in rigidity.
Here are the top 7 mistakes when using bottled builder:
🌿Mistake # 1 Overlaying the wrong length nails
This has to be the most common mistake I see nail artists make when using bottled builders.
Natural nail length will dictate who is the appropriate candidate for a bottled builder gel application. In general the answer is short to medium length natural nails. Use them on longer lengths at your own discretion.

The thinner viscosity of a soft gel bottled builder makes it more flexible, and therefore if you overlay long length nails with it, those nails often will not be properly supported. They will flex more often than we want them to, leading to lifting, tears and thereby natural nail damage.
🌿Mistake #2 Applying the bottled builder gel too thick
When you are working with builder gels, pot or bottled, you have to pay special attention to their viscosity. Their viscosity is directly correlated to their strength. You have to give the viscosity of the gel the power to give you the correct structure.

I often tell students, -you- are a structure gel specialist because you use structure gel. You use gels with different viscosities to structure the nails– not because you put on the structure on the nails. Yes, you are in charge of guiding that gel to form the correct structure. But your goal is not to bulk up the nail to make it look structured.
The viscosity of the gel is a hint as to how thick you should structure the nails. Generally speaking lower viscosity gels will require less structure. Higher viscosity gels will naturally yield more structure to the application.
🌿Mistake #3 Building too long of a length with bottled builders
Can you extend the length of natural nails with bottled builders? Yes.
However, first, I would do so with clear, not a tinted base, and only up to a third of the amount of nail plate attached to the nail bed, extended as free-edge.

Bottled builder gel is weaker than a true hard gel, or even a more viscous soft gel builder (like those of Japanese gel brands).
It’s always better to be more conservative with your lengths when using bottled builders. Not only because they are a bit more flexible, but because they are not meant to be applied thick. And so trying to overlay the new extension with bottled builder will just be more work as you try to reinforce it in several layers. As we previously mentioned, you shouldn’t apply bottled builder too thick, especially in just one go, or one layer.
🌿Mistake #4 Working too slow
By now you are understanding that bottled builder gel is more thin, and more flexible than a higher viscosity gel. It’s just naturally more runny.
So ideally you want to work one nail at a time, and quickly guide that gel where it needs to go. If you don’t move quickly, it will run into the skin, or go flat and lose its structure, thereby losing its support.
🌿Mistake #5 Not shaping after building
When I first started using bottled builder approximately 5 years ago, I noticed I would get inconsistent wear at the free-edge. Often the gel would start lifting.

This is because harder gels, whether they are semi-hard or true hard gel, cannot be left too thin around the perimeter or they can lift or crack. Yes, adding a softer gel base underneath your harder gel mitigates that risk, but at the free-edge where there is more impact on the nails with day to day wear, the best thing is to actually file off the natural nail underneath. This keeps the product from splitting away from the natural nail, when their flexibility is too incompatible.
And you don’t have to do so significantly. Unless you are fixing a nail that curves downward 1-2mm is often sufficient.
🌿Mistake #6 Purchasing non-professional grade builder gel products
Buying low quality gel products from sources or brands not professionally regarded, is gambling with your health at the highest levels.
Gel nails are part of a chemical industry. The products issued to us must be carefully crafted for safe application. The only way we can bet a brand ourselves without knowing too much about chemistry, is to purchase from a reliable time-tested brand.

Out of all the gels, unfortunately bottled builder gels can be manipulated the most by unethical companies. They often can be filled with more monomer and acid than they need to have in order for them to self-level more easily, and adhere to the natural nail more aggressively.
High levels of monomer and acids in gels can make you allergic or sensitive to the gel nail products. Often high levels of these two components also inhibit the gel formula from curing properly… No matter how long you cure it for– an improper cure also leads to allergic reactions or chemical burns.
Do not gamble with your health, and make the mistake of buying cheap and easily accessible bottled builders on sources like Amazon, Temu, etc…
Not only can bad gel formulas cause chemical burns and make you allergic to other nail products, not just gel, but also medical procedures that may involve resin materials similar to those found in nail gels.
🌿Mistake #7 Not investing in a professional grade curing unit
The only best way that I know as a professional how to buy the best curing unit, is to buy your curing unit with the same diligence that you buy your nail gel products… From a time-tested reputable nail gel brand.
My recommendation is to buy the one from your number 1 or your number 2 most used gel brand.
Improper cure is the fastest, easiest way to an allergic reaction using nail gels.
In addition, your high quality products can’t perform at their best potential without a proper cure anyways.
This means, no high-gloss scratch-resistant finishes. No firm structured overlays. And lots of lifting and other troubleshooting scenarios.
Gel nails are a prestigious service… They often don’t get the respect as the luxury nail service they truly are.
Proper use starts with professional grade products, both formulas and curing lamps.

I hope you enjoyed learning about the 7 most common mistakes with builder gel nails.
As a reminder my Nail Thoughts Bottled builder gel class certification is happening soon. Find all the details HERE

Or you can sign up to my signature non-brand specific course, Master Gel Nails, where I help you apply structure gel on natural nail lengths.
Thank you for watching and I’ll see you in the next one. Bye for now.

Paola Ponce is a licensed nail tech of 10+ years and a certified Japanese gel educator.
Learn more about her journey as a specialized gel nail artist and her gel nail application course inside her free masterclass here.
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