General Finishes High Performance Topcoat, Flat, Gallon

General Finishes High Performance Topcoat, Flat, gallon (GF item GAHF, UPC 606016109340). Available to order now at Project Weekend DIY.

Ship time: Orders usually ship in 2 to 4 business days, then standard delivery takes 3 to 7 business days, so plan on about 1 to 2 weeks. Free shipping at $75+ (lower 48 + DC); under $75, FedEx or UPS rates show at checkout. Shipping policy

High Performance Flat, gallon size

Painted kitchen cabinets, a run of built-ins or several doors call for a gallon, and this one holds General Finishes High Performance in Flat (10 or less on the sheen scale). Fine Woodworking named High Performance its "Best Overall Choice," with voters calling it the hardest, most durable consumer polyurethane topcoat. It is a water-based urethane/acrylic for interior use that brushes, rolls, pads or sprays, and it doesn't amber in the can.

Free shipping at $75, no code needed (lower 48 + DC). Free 30-day returns with a prepaid label on unopened cans; opened paint can't be returned (refund policy).

How far a gallon goes

GF lists 500 to 600 sq ft per gallon per coat, so a two-coat job finishes about 250 to 300 sq ft and a three-coat job about 165 to 200 sq ft. GF advises 2 to 3 coats and no more than 3; extra coats don't add durability. Solids are 27% by volume.

Hand-application habits for a flat sheen

• Stir from the bottom before and during the job; flatting agents settle.
• Thin with distilled water, 5% up to 10% by volume, if you want it to flow more.
• For more open time add 10 to 15% GF Extender where rules allow. In California, more than 2% Extender makes the product non-compliant with SCAQMD.
• Spray at 3 to 5 mils wet with an HVLP 1.1 to 1.3 mm tip and medium air cap, gun 6 to 8 in from the surface, overlapping passes 25%.
• Between coats use a 220-320 sanding pad, never steel wool.

Dry time and blush

At 70 F and 50% humidity, recoat after 2+ hours. A fine 220-320 pad that raises powder means the coat is dry. Rushing traps moisture and causes blush, a cloudy look; humidity over 80%, cool rooms, thick coats and work over another brand's finish all stretch the wait. Over oil-based stain or finish, wait 72+ hours. Do not use over white or light paints such as Milk Paint whites, since any clear coat can yellow over them. Light use after 7 to 10 days, full cure in 21 days.

Siblings: Clear Satin Gallon and Dead Flat Gallon.

Manufacturer part number: GAHF

Questions

Why does my flat topcoat streak, and how do I stop it? General Finishes explains that more flatting agent makes a topcoat more likely to streak when hand-applied. With Flat, apply a liberal amount, avoid pressure and back-brushing, wipe with the grain, and use a large applicator such as a paint pad on big surfaces. Buff out streaks with a 220-320 pad or sand and recoat; spraying gives the smoothest result.

Is High Performance Flat the same as Flat Out Flat? No. GF says Flat Out Flat is a self-crosslinking acrylic with a wax-like, softer feel for low-use pieces, while High Performance is urethane-based, slightly harder and clearer, and the better choice for tabletops and kitchen cabinets.

Can I mix Flat with Satin to get something in between? Yes. GF says the Flat, Satin, Semi-Gloss and Gloss High Performance sheens can be mixed to adjust sheen. Dead Flat is a different polymer and can't be mixed with the others.

Can I return it? Yes. Unused, unopened cans can be returned within 30 days, and we send a free prepaid return label. Opened paint can't be returned.

How fast does it ship? Orders usually ship in 2 to 4 business days, and standard delivery takes 3 to 7 business days after that. Shipping is free on orders of $75 or more (lower 48 + DC).

High Performance Flat information comes from the General Finishes High Performance page and GF answers on Flat Out Flat vs High Performance. Every sheen and size: General Finishes High Performance topcoat.

Smaller Flat sizes: Flat quart and Flat pint.

Data sheets: High Performance technical data sheet (Dec 2021); High Performance Flat safety data sheet (Feb 2025).

Free standard shipping on orders $75+ to the lower 48 states and DC. Some large or heavy items are excluded at checkout.

30-day returns on unused, unopened items. Returns accepted within 30 days. We send you a prepaid return label. Contact us within 30 days of delivery to start a return. Opened paint, aerosols, flammables, special orders and sale items can't be returned. Read the full refund policy.