ANSWER:
It depends! Read on, or watch this GF video demonstration: http://youtu.be/torOAQy91q4
*Here are the main questions to ask yourself:
- Is my underlying product water or oil based?
- Am I OK with the finish darkening or yellowing with time?
- Is fast dry time a priority?
- Will I spray or hand-apply the product?
- Will this piece be used indoors or outdoors?
- Am I O.K. with solvent odors during application?
- Is my project detailed or large?
- Does this top coat have the sheen I'm looking for?
HIGH PERFORMANCE WATER BASED TOP COAT: Winner of Fine Woodworking's Best Overall Choice Award, High Performance Top Coat is one of the most popular water based top coat's on the market today.
CHARACTERISTICS:
- Water Based
- Clear (non-yellowing)
- Dry Time to Recoat: 2+ hours
- Cure time: 21 days
- Coats recommended: 3 minimum
- Spray or hand-application: Acrylic brush, foam brush, paint pad applicator, or spray: HVLP 1.3 (.051) needle nozzle.
- Interior application only
- Low odor
- Soap and water cleanup
- Ideal for detailed pieces and any size project
- Sheens: Flat, Satin, Semi-Gloss, and Gloss.
Video: How to spray General Finishes Water Based Top Coat: http://bit.ly/1wuurwI
Video: How to hand apply General Finishes Water Based Top Coat: http://bit.ly/1v4ne8b
ENDURO-VAR, a water-based self-crosslinking polyurethane
CHARACTERISTICS:
- Water Based
- Darkens/ambers with time
- Dry Time to Recoat: 4+ hours
- Cure time: 21 days
- Coats recommended: 3 minimum
- Spray or hand-application: Acrylic brush, foam brush, paint pad applicator, or spray: HVLP 1.3 (.051) needle nozzle (nozzle tip size estimate)
- Interior application only.
- Low Odor
- Soap and water cleanup
- Ideal for detailed pieces and any size project
- Sheens: Flat, Satin, Semi-Gloss and Gloss.
ARM-R-SEAL OIL BASED TOPCOAT: Winner of Fine Woodworking Magazines Best Overall Award, Arm-R-Seal is a long time favorite of the woodworking world. Arm-R-Seal topcoats are made with only the highest quality urethane resin, making them extremely durable and long lasting. They penetrate to provide deep protection and a "natural" look.
CHARACTERISTICS
- Oil-based penetrating finish
- Darkens/ambers with time
- Dry Time to Recoat: 12-24+ hours
- Cure Time: 30 days
- Coats recommended: 3 minimum
- Hand application: Cloth, natural bristle brush, foam brush, paint pad applicator
- Interior Application only
- Solvent odor
- Clean up with mineral spirits
- Ideal for detailed pieces and any size project
- Sheens: Satin, semi-gloss and gloss
If you want fast build or a soft satin sheen, use oil based GEL SATIN Topcoat. It is a heavy duty oil and urethane oil base top coat, which produces a beautiful hand rubbed quality finish. Gel satin has a thicker consistency, so there are no drips, runs or spills. GF developed this finish as a "sister" to GEL STAIN.
CHARACTERISTICS
- Oil-based topical finish
- Darkens/ambers with time
- Dry Time to Recoat: 12-24+ hours
- Cure time: 30 days
- Coats recommended: 3 minimum
- Hand application: Cloth, natural bristle brush, foam brush, paint pad applicator
- Interior application only
- Solvent odor
- Clean up with mineral spirits
- Not ideal for detailed pieces or large projects because of the viscosity
- Sheen: Satin
GF Video Demonstration - How To Apply Gel Top Coat
Designed for exterior wood applications, EXTERIOR 450 outdoor varnish provides your wood with a tough, protective finish that will withstand the rigors of the sun, rain, and wind. It is suitable for patio furniture, garage doors, entrance doors, outdoor kitchens and interior windows. It is not recommended as a deck finish.
Fortified with UV absorbers to help minimize fading and maximize performance, Exterior 450's built-in mildewcide retards mold and mildew growth. Exterior 450 is tough and flexible, and will resist the expansion and contraction of the wood through hot summers and cold winters that typically causes cracking and peeling.
CHARACTERISTICS:
- Water Based
- Clear (non-yellowing)
- Dry Time to Recoat: 2+ hours
- Cure time: 21 days
- Coats recommended: 3 minimum
- Spray or hand-application: Acrylic brush, poly foam brush applicator, or spray: HVLP 1.3 (.051) needle nozzle
- Exterior (outdoor) finish
- Low Odor
- Soap and water cleanup
- Ideal for detailed pieces and any size project
- Sheen: Flat, Satin, Semi-Gloss and Semi-Gloss
*General Principles:
PRODUCTS THAT NEED TOPCOAT
All stains need a topcoat, even GF's Gel Stains since they are loaded with pigment. Essentially, the stain is the colorant and the top coat protects/seals everything in.
Milk Paint does not need to be sealed with topcoat when low to medium wear is expected.
WATER VS. OIL-BASED PRODUCTS
Unlike oil-based products, water-based topcoats do not yellow over time (except Enduro-Var, a hybrid finish.)They are low-odor, take less time to dry, and spills clean up with soap and water. Oil-based topcoats amber, and penetrate the surface of the wood more, bringing both the grain of the wood to life, but also accentuating irregularities in the wood.
NUMBER OF COATS:
Normally 3 coats of a combination of sealer and/or topcoat are recommended.
DRY TIME VS. CURE TIME
Dry time is the amount of time you should wait before applying the next coat of finish or top coat. However, a longer wait time is essential when applying a water based and oil based product on top of one another (more information: Water vs. Oil Based Products). Cure time is the amount of time you should wait before using your refinished piece.
WOOD SPECIES
Every species of wood is different; every tree is unique and will have a varying effect on the finished result. Be sure to test your topcoat in a hidden area first.
WATER FINISHES WARNING: Never use any water-based topcoat with long oils such as Danish, Tung or Linseed.
OIL FINISHES WARNING: Always take care to dispose of oil-based soaked application materials safely according to your local regulations.
LARGE/DETAILED SURFACES: For more complex projects that have a lot of nooks and crannies or projects with large surface areas such as cabinets, we recommend ARM-R-SEAL liquid oil-based topcoat or HIGH PERFORMANCE water based top coat, or ENDURO-VAR, available in Flat, Satin, Semi-gloss and Gloss.
PROFESSIONAL TOPCOATS
Finally, General Finishes offers a full line of professional topcoats designed specifically for spray applications. Visit GF's website to see our professional product line: http://bit.ly/1tLDXcw