Varathane Triple Thick Polyurethane is a one-coat clear finish for interior wood. Varathane says the brush-on formula is 3X thicker than its Ultimate Water-Based Polyurethane and self-levels, so most projects are done in one coat, with scratch and stain resistance, a soft amber hue and soap and water cleanup. The aerosol version, Triple Thick 3X Polyurethane Spray, is an oil-modified urethane that sprays at any angle, even upside down. Both are made for furniture, doors, trim and cabinets, and neither is recommended for floors or outdoor surfaces. Everything on this page comes from Varathane's technical data sheets and safety data sheets.
Triple Thick sizes we carry
Can or spray: specs from Varathane
|
Triple Thick Polyurethane (quart) |
Triple Thick 3X Spray (11.25 oz) |
| Base |
Water-based acrylic and polyurethane dispersion |
Oil-modified urethane (acetone, mineral spirits, VM&P naphtha) |
| Coverage |
About 50 sq ft per quart |
About 40 to 50 sq ft per can |
| Dry and recoat |
Touch in about 2 hours; recoat after 2 hours |
Touch in about 1 hour; handle in 2 hours |
| Use |
Light use after 48 hours; full cure in 7 days |
Full use after 24 hours |
| Apply at |
60 to 90°F, humidity below 85% |
55 to 90°F, humidity below 85%, out of direct sunlight |
| Apply with |
High-quality synthetic bristle brush, one thick, even coat with the grain |
Light mist coats from 10 to 12 inches |
| Cleanup |
Soap and water |
Mineral spirits |
| VOC |
Under 275 g/L on the data sheet; 184 to 195 g/L by sheen on the current safety data sheets |
Data sheet lists MIR 0.75 maximum (a reactivity rating) instead of g/L |
| Flash point |
Above 200°F |
Extremely flammable aerosol |
How to apply it
Start with clean, dry wood free of wax, grease and dust. Sand smooth, working from 120 to 220 grit for the brush-on version (150 to 220 grit before spraying), vacuum, and wipe with a lint-free cloth. Over stain, Varathane says to let the stain cure fully first and test a sample for compatibility; it recommends Varathane wood stains underneath. Stir the can, don't shake it, and brush on one thick, smooth coat in the direction of the grain. For a second coat or over an old finish, sand with 220 grit first. With the spray, shake the can hard before and during use, mist on light coats with a smooth, sweeping motion, and turn the can upside down for hard-to-reach spots.
Varathane warns that the spray can discolor white or pastel paints and stains, so test it in a hidden spot first. Existing finished wood can be refinished without stripping, but it must be cleaned of wax, silicone and polish and then scuff-sanded.
Shop related: all Varathane, every brand in polyurethane, spray polyurethane and clear sprays, and protective finishes and topcoats.
FAQ
Is Triple Thick really one coat?
Varathane designed the brush-on formula so most projects are done in one coat, about 3 mils dry. If you want a second coat, it can be recoated after 2 hours; sand with 220 grit first.
Can I use Triple Thick on floors or outdoors?
No. Varathane's data sheets say neither the brush-on nor the spray is recommended for floors or outdoor surfaces. For floors, see the Varathane floor finishes in our Varathane collection.
Is Triple Thick water-based or oil-based?
The brush-on quart is water-based and cleans up with soap and water. The Triple Thick 3X spray is an oil-modified urethane that cleans up with mineral spirits.
Does Triple Thick yellow?
Varathane says the brush-on formula has a soft amber hue, and it cautions that the spray can discolor white or pastel paints and stains. Test on a hidden spot or scrap first.
How long before I can use the piece?
For the brush-on version, allow 48 hours before light use and 7 days for full cure. For the spray, allow 24 hours before full use.
Can I return it?
We offer 30-day returns on unused, unopened items. Opened paint, aerosols and flammable liquids can't be returned, so the Triple Thick spray is final sale under our refund policy.
Shipping is $5.99 on orders under $35 and free on orders of $35 or more, to the lower 48 states and DC (shipping policy).
Sources: Varathane Triple Thick Polyurethane technical data sheet VAR-35 (rev. 040325), Varathane Triple Thick 3X Polyurethane Spray technical data sheet VAR-64 (rev. 021017), and Rust-Oleum safety data sheets for 284470 (4/23/2025), 284472, 284473 and 304588 (3/6/2026), and 318289, 318290 and 318291 (3/13/2026).
