Symplex Spartan SiO2 Review: How to Apply It and How Long It Lasts

What Spartan SiO2 Is

Spartan SiO2 is Symplex's water-based spray sealant, made with silicon dioxide and what Symplex calls advanced super polymers. It works two ways: as stand-alone protection on paint, glass, plastics and trim, or as a maintenance layer on top of a ceramic or graphene coating. Symplex rates it for 3+ months, and says to reapply every 1–2 months when you use it as a topper, or whenever the beading drops off.

It's the lowest-priced sealant in the Spartan line. We stock it by the pint, the gallon and the 5-gallon pail.

How to Apply Spartan SiO2

These are Symplex's own directions. Most of the work is prep.

The Spartan Line, Side by Side

Spartan comes in three versions. Two go on a dry car and one goes on during the wash, and that difference decides which one you want.

Spartan Graphene goes on the same way as Spartan SiO2. Symplex says the graphene adds durability, cuts down water spotting and improves chemical and UV resistance. It rates it for 4+ months, with a refresh every 2–3 months or after exposure to strong detergents. The pint is $22.37.

Spartan Aqua Guard is the one to buy if you want protection that goes on during the wash. Symplex designed it for wet application: two to four mists per panel on the wet car, then rinse right away with strong water pressure. You can also mix it 1:5 and spray and wipe. It's listed for paint, clear coat, glass, plastic trim, chrome, vinyl and wheels, and Symplex asks you to keep the surface dry for 12 hours afterward.

Which one is better? It depends on what you're after. Spartan SiO2 costs the least per ounce: about $0.29 by the gallon. Graphene carries the longer rating and the added spotting, chemical and UV resistance, for about $0.34 an ounce by the gallon. Aqua Guard is the only one of the three that goes on during the wash.

Spartan SiO2 vs CarPro Reload 2.0

Reload 2.0 is the spray sealant most people compare it to. CarPro says Reload 2.0 goes on wet or dry, gives up to 3 months of protection on a daily driver, and is made to maintain CQuartz coatings. Going on wet or dry is a real advantage, and Spartan SiO2 doesn't have it. The big difference is price.

If you'll be sealing a dry car anyway, Spartan SiO2 costs about a sixth as much per ounce by the gallon, with a rating at least as long. If you want a sealant you can use while you dry, look at Spartan Aqua Guard or Reload 2.0. We compare Reload 2.0 with EliXir, HydrO2 Lite and the whole Spartan line in CarPro Reload 2.0 Alternatives.

Where It Sits on the Symplex Sealant Ladder

P2 is the long-haul option: 100% synthetic cross-linking polymers, a high-gloss wet look, and a 6–8 month rating. It takes more work. Symplex recommends clay and paint correction first. You apply it by hand with a foam or microfiber pad in circular motions, let it haze for 5–10 minutes, buff it off, and keep water off it for at least 12 hours.

Which Size Should You Buy?

The pint is $18.83, about $1.18 an ounce. The gallon is $37.71, about $0.29 an ounce, and the 5-gallon pail is $160.17, about $0.25. If you seal cars regularly, the gallon costs about a quarter as much per ounce as the pint.

What to Pair It With

Wash with a soap that won't strip what you just put down. Platinum is pH 7.0–7.5, and Symplex formulates it to be safe on wax, sealants and ceramic coatings. Silica Wash cleans and adds SiO2 protection in one step, and Symplex says it won't strip existing waxes or sealants.

Who It Isn't For

If you want to seal the car during the wash, Spartan SiO2 isn't the product; that's Spartan Aqua Guard. If you can't keep the car dry for a few hours after sealing, pick a different day or a covered spot. And if you'd rather seal once or twice a year than every few months, look at P2 and its 6–8 month rating.

Verdict: Is Spartan SiO2 Worth It?

Yes, if you'll do the prep. The application itself is quick: mist, spread, buff. It carries a 3+ month rating, and by the gallon it costs about $0.29 an ounce. Most of the work is in the steps around it: wash, dry, wipe down, use two towels, then give it a few dry hours. That's what Symplex's directions call for, so plan for it.

Frequently Asked Questions

How long does Symplex Spartan SiO2 last?

Symplex rates it for 3+ months. Used as a topper over a coating, Symplex says to reapply every 1–2 months, or whenever the water beading drops off.

Can I use it as a drying aid?

No. Symplex's directions start with a washed and dried surface wiped down with an alcohol-based inspection spray, and ask you to keep water off it for 3–4 hours. For protection that goes on the wet car, Symplex makes Spartan Aqua Guard.

What's the difference between Spartan SiO2 and Spartan Graphene?

They go on the same way. Graphene adds graphene reinforcement that Symplex says improves durability, cuts water spotting and boosts chemical and UV resistance, and it's rated for 4+ months against 3+ for Spartan SiO2.

Is it safe over a ceramic coating?

Yes. Symplex sells it as a maintenance layer for ceramic or graphene coatings, as well as stand-alone protection for paint, glass, plastics and trim.

Does it need to cure?

Yes. Protection starts forming within minutes, but keep it away from water and rain for 3–4 hours. The full cure takes 24 hours.

Will it streak on dark paint?

Streaks usually come from too much product, a loaded or damp buffing towel, or a hot panel. Symplex's directions cover all three: two or three mists per panel, a cool surface in the shade, and a second clean, dry microfiber to level and buff. Our ceramic spray application guide goes deeper on technique.

Which size is the best value?

Per ounce, the 5-gallon pail, at about $0.25. For most people the gallon makes more sense: $37.71, or about $0.29 an ounce, against about $1.18 for the pint.