Water-Based High Gloss Acrylic Cure and Seal: Solids Content Explained

What does the solids percentage on cure and seal mean?

It is the share of the liquid that stays on the slab as acrylic resin after the water or solvent evaporates. A 25% product leaves about a quarter of what you spray as film; the rest flashes off. Euclid’s curing and sealing blog says it simply: higher solids content produces a thicker film.

Most concrete cure and seal on the shelf sits near 25%. Euclid notes many products are formulated right around 25%, with some at 30% or higher. Lighter products run 10% to 20% and are mostly sold as curing compounds that leave a light sheen.

How thick is the film at 15%, 25% and 30%?

Euclid gives about 0.8 mil at 15%, 1.3 mils at 25% and 1.6 mils at 30%. For scale, it compares those to a kitchen trash bag at 1.2 to 1.7 mils. A mil is a thousandth of an inch (25.4 µm), so even the heaviest of these is thinner than most paint coats.

Those figures line up with a spread rate of 300 ft²/gal (7.4 m²/L). The spread rate moves the film as much as the percentage does. A US gallon spread over 1 ft² is about 1,604 mils wet, so dry film is roughly 1,604 divided by the rate, times the solids fraction:

These are estimates from our own math, assuming the label percentage is solids by volume. The takeaway: a 25% product laid on heavy at 200 ft²/gal puts down more film than a 30% product at 300. Run your slab size through the coverage calculator and buy for the label rate, not the percentage.

What solids content does ASTM C1315 require?

At least 25%. The Dayton Superior technical notes on cure and seals list the C1315 limits as a 25% minimum solids content and a maximum water loss of 0.40 kg/m² in 72 hours at 300 ft²/gal. The plain C309 curing spec has no solids floor. See the ASTM C1315 standard page for the classes and types.

The class letter tells you about yellowing. Dayton defines Class A as non-yellowing and Class B as allowing moderate yellowing. For clear exterior work in sun, Type I Class A is the claim to look for.

A higher percentage does not prove a C1315 claim, either. Dayton’s own list shows its 30% J23UV and its 25% J20UV meet only C309, while its 25% J22UV and J22WB meet C1315 Type I Class A. Read the standards line on the data sheet, not the number on the front of the jug.

Is 30% solids better than 25%?

Only slightly, and it costs you some ease of application. Euclid says it is hard to imagine the extra 0.3 mil of acrylic from a 30% product provides much at all. It also warns that higher-solids cure and seals are harder to apply and need a sprayer and tip built for a thicker liquid.

The older Euclid cure and seal application guide says most sprayers come with a 0.5 gpm nozzle, and higher-solids materials may need a 1 gpm (3.8 L/min) nozzle. Spray 30% through a small tip and you get spitting, heavy spots and roller marks when you backroll.

Where 30% makes sense: decorative exterior work where the owner wants a wet look and you plan on two coats anyway. W. R. Meadows pitches its 30% solvent SEAL CURE-30 for “any place a higher sheen finish is desired,” at 600 ft²/gal per coat in two coats.

Does higher solids mean more gloss?

Partly. Solids add film, and film adds sheen, but the base, the resin and the coat count matter as much. Euclid’s application guide says the amount of gloss depends on the specific cure and seal used and the number of coats. Its first thin coat soaks in with little or no sheen; the second coat gives the gloss.

Cemstone’s 2025 selection guide shows how loose the link is. Its 25% solvent Cure and Seal is listed as satin, its 25% solvent Super Clear Coat as clear gloss, and its 30% water-based Cure and Seal Plus as glossy. Same percentages, different finishes.

Can water-based cure and seal be high gloss?

Yes. Dayton’s J22WB is a water-based acrylic at 25% solids sold with a high gloss finish, non-yellowing, and meeting both C309 and C1315. Foundation Armor’s WB25 is also 25% water-based, milky white when wet and high gloss when dry, with a C1315 Type 1 Class A claim.

As a group, water-based runs flatter. Euclid’s blog says water-based cure and seals tend toward a lower gloss, matte finish, while solvent-based ones wet out and penetrate more. It rates their toughness and durability as comparable. Foundation Armor also notes gloss can drop on porous pavers.

What the data sheets say

Here are solids, base, standards and finish exactly as each maker states them. This is not a ranking, and the finish words are the makers’ own.

Sources: the Nox-Crete Cure and Seal data sheet, the Quikrete 8730 data sheet, the Super Aqua-Cure VOX data sheet, the Dayton J23UV page and the sheets linked above.

Two things stand out. Nox-Crete sells one line in three strengths, and only the 25% version carries the C1315 claim. And Dayton’s 30% solvent product claims less than its 25% ones.

If you already put down too much

Watch for bubbles, whitening, peeling and soft spots that won’t dry. Euclid’s Super Aqua-Cure VOX sheet lists failure to dry, bubbling, whitening, peeling and flaking when the product goes on too heavily, in too many coats, or is resealed too often. High-solids product makes that easier to do in one pass.

Puddles and lap marks dry darker, which is where blotchy finishes come from. On solvent-based product, a xylene wash can re-wet and level the film. On water-based product that has already failed, plan on stripping. Our guide to cure and seal peeling, flaking or blotchy walks through each case.

Indoors, a heavy film is a bigger problem, since most finish flooring won’t bond over it. Check the curing compound and flooring guide before tile, epoxy or glue-down goes over a sealed slab.

How do you get high gloss without buildup?

Use two thin coats instead of one heavy one. SpecChem’s product selection guide says two thin coats produce a better gloss than one heavy coat, and that over-application leaves a mottled look and can trap moisture.

• Spray at the label rate and backroll puddles out. The Euclid VOX sheet calls for 300 to 400 ft²/gal (7.4 to 9.8 m²/L) on the first coat over new concrete.
• Recoat inside the window on the data sheet. Foundation Armor says two WB25 coats 6 to 8 hours apart, and no more than 24 hours apart.
• Stay in the temperature range. WB25 calls for 55°F to 85°F (13°C to 29°C); Nox-Crete says its line does best above 55°F (13°C).
• Use a high-solids nozzle for 25% and up, as the VOX sheet specifies.
• Don’t reseal every year. Recoat when the old film has worn, after a light scuff and clean.